ASHS 2025 Conference: Full Schedule

2:30pm CDT

Postharvest Interest Group Business Meeting

Tuesday July 29, 2025 2:30pm - 4:00pm CDT

Strand 3

Open to all attendees.

Tuesday July 29, 2025 2:30pm - 4:00pm CDT
Strand 3

Meetings Committee/Division/Interest Groups

Subject Postharvest

4:00pm CDT

PH 1 - 1-Methylcyclopropene (1-MCP) Effects on Fruit and Vine Quality of Cluster Tomatoes

Tuesday July 29, 2025 4:00pm - 4:15pm CDT

Foster 1

Effects of 1-MCP on tomato fruit ripening have been well studied, but much less attention has been given to its effects on vine quality. In a series of experiments, 0.5 or 1 µL L-1 1-MCP was applied to tomato clusters when the least mature fruit on the vine was mature green (MG), breaker (BR) or light red (LR). The clusters were stored at 12oC for 18 days. Overall fruit quality remained high in the MG, BR and LR fruit clusters for 18, 9, and 6 days, respectively. Quality of the 1-MCP-treated BR stage fruit did not decline until after 12 days, while little effect of 1-MCP was found for the LR fruit. Cluster weight was not affected by 1-MCP treatment. However, visual appearance of the vine tissues was greatly affected by 1-MCP. Loss of vine quality was lowest in the MG vines without 1-MCP treatment. However, the highest quality ratings were found in 1-MCP treated vines, regardless of fruit maturity. Retention of vine quality by 1-MCP was closely associated with reduced water loss from the vine tissues. These results confirm that 1-MCP can delay ripening of tomato fruit, but also highlight that the benefits of 1-MCP may be through better visual appearance of the cluster vines.

Speakers

Chris Watkins

Cornell University

Co-authors

Cheon Soon Jeong

Kangwon National University

Jennifer DeEll

Ontario Ministry of Agriculture, Food and Agribusiness

Seok-Kyu Jung

Daegu Catholic University

Youngjae Shin

Dankook Univiversity

Tuesday July 29, 2025 4:00pm - 4:15pm CDT
Foster 1

Oral presentation, Postharvest 1

Subject Postharvest
Funding Source Ontario Greenhouse Vegetable Growers, AgroFresh, Inc., NIFA Multistate NE2336

4:15pm CDT

PH 1 - Non-destructive quality assessment of tomatoes through MQ gas sensors

Tuesday July 29, 2025 4:15pm - 4:30pm CDT

Foster 1

Fresh produce quality is a critical determinant of consumer preference and market value, with high-quality tomatoes often fetching premium prices. Traditional quality assessment methods, though effective, are typically labor-intensive, destructive, and impractical for real-time monitoring. In this study, we explore the potential of low-cost ($0.99 per unit) metal oxide semiconductor (MOS) gas sensors—MQ series (MQ2, MQ5, MQ6, MQ7, MQ9, and MQ135)—as a rapid, non-destructive, and cost-efficient tool for distinguishing high-quality tomatoes based on their cultivation in nitrogen-rich or nitrogen-deficient soils. Organic tomatoes, harvested from plants exposed to relatively high (High-N) and relatively low (Low-N) levels of bioavailable nitrogen (N) were enclosed in airtight containers equipped with MQ sensors to capture their volatile organic compound (VOC) emissions over 48 hours. Three replicates were used for each N level. Complementary laboratory-based quality assessments measured fresh weight, soluble sugar content, titratable acidity, pH, firmness, color space (Lab*), antioxidant capacity (DPPH assay), and total phenolic content. Gas chromatography-mass spectrometry (GC-MS) was utilized for VOC profiling. The resulting sensor and analytical data were preprocessed and normalized, followed by training 193 machine learning models with principal component analysis (PCA) at a 95% variance threshold in MATLAB. Significant differences were observed between High-N and Low-N treatments across several quality parameters. High-N tomatoes exhibited a 25.32% increase in average fruit fresh weight (p = 0.002), whereas Low-N tomatoes had 18.80% higher firmness (p = 0.020). Low-N tomatoes showed a 27.09% increase in antioxidant capacity (p = 0.0001), a possible indication of an adaptive response to N deficiency. Whereas VOC analysis revealed higher concentrations of octanoic acid, nonanoic acid, and 2-methyl-1-propanol in High-N tomatoes, with increases of 142.67%, 191.46%, and 37.72%, respectively, compared to Low-N tomatoes (p = 0.007, p = 0.020, p = 0.040). Sensor performance analysis demonstrated that MQ9 and MQ5 sensors were the most effective in differentiating between the two nitrogen treatments, with ensemble learning, neural networks, and support vector machines achieving 100% classification accuracy, followed by MQ135 and MQ2. Feature reduction criterion identified a minimal yet highly discriminative subset—including MQ9 sensor responses, octanoic acid, 4-heptanone, nonanoic acid, 1-penten-3-ol, 2-methyl-1-propanol, limonene, 3-methylbutanoic acid, 2-heptanone, fresh weight, and DPPH values—yielding classification accuracies of 97.06% during training and 89.29% in testing with a tri-layer neural network model. These findings underscore the potential of low-cost MOS gas sensors, particularly MQ9, as a viable, non-destructive alternative for real-time quality assessment of tomatoes.

Speakers

Ali Ahmad

Pennsylvania State University

Co-authors

Erin Rosskopf

USDA-ARS

Francesco Di Gioia

Pennsylvania State University

Jaime Lloret

Universitat Politècnica de València (UPV)

Jinhe Bai

USDA-ARS

Sandra Sendra

Universitat Politècnica de València (UPV)

Thais P Freitas

USDA-ARS

Tuesday July 29, 2025 4:15pm - 4:30pm CDT
Foster 1

Oral presentation, Postharvest 1

Subject Postharvest
Funding Source WA Tree Fruit Research Commission

4:30pm CDT

PH 1 - A Robust UHPLC Method Using Multiple Modifiers for Carotenoid Analysis of Tomatoes of Different Colors

Tuesday July 29, 2025 4:30pm - 4:45pm CDT

Foster 1

Carotenoids are natural pigments that give fruits and vegetables their yellow, orange, and red colors, and their consumption is associated with numerous health benefits. Most carotenoids occur in isomeric forms (primarily cis and trans); this poses challenges for efficient separation and identification during chromatographic analysis. Tomato (Solanum lycopersicum), an economically important crop, has high nutritional and health benefits, attributed mainly to carotenoids. Lycopene, a major carotenoid in tomatoes, predominantly exists in the trans isoform; however, the trans isoform is less bioavailable than the cis isoform. To accurately measure these isoforms in tomatoes and thus provide information for breeding tomatoes with more cis lycopene, we aimed to develop an Ultra-High Performance Liquid Chromatography (UHPLC) method based on mobile phase (MP) modifiers to measure a wide range of carotenoids (cis and trans) across different tomato varieties (heirloom and cherry) with different colors (green, yellow, orange, purple, and red). The chromatographic parameters, such as temperature (15-30 °C), flow rate (0.3-1.5 ml/min), column lengths (50, 150, and 250 mm), and gradients, and MP modifiers (water, acetonitrile, tetrahydrofuran, triethylamine, ammonium acetate, and ethyl acetate) were optimized. Among the tested parameters, methanol and tert-butyl methyl ether as MP, including ethyl acetate (10%) as a modifier, and C30 column (150 x 4.6 mm) at 20 °C gave the best resolution, allowing the separation of up to 20 peaks indicating individual compounds and isoforms in 35 min. The optimized UHPLC method was also validated for complete profiling, recovery, precision, limit of detection, and quantification. The complexity of the profile based on the number of peaks followed the following order: Orange Heirloom (15) > Orange Cherry (15), Red Cherry (15) > Red Heirloom (13) > Green Heirloom (13) > Purple Cherry (13) > Yellow Cherry (2). Among all the tested tomatoes, trans-lycopene, 5-cis-lycopene, and β-carotene were the predominant carotenoids, followed by 9- and 13-cis-lycopene, and for the first time, mutatoxanthin was detected in Orange Heirloom tomatoes. This method provided efficient peak separation resolution, although not all of them were identified as potential carotenoids; however, their identification could be confirmed by mass spectrometry analysis in future studies. The efficiency, separation, and quantification in this method make it robust for carotenoid analysis in any tomato variety regardless of color. USDA-NIFA-2024-51181-43464 supported this work through the Vegetable and Fruit Improvement Center and partially funded by the Texas A

Speakers

Braulio Cervantes

Texas A

Co-authors

Bhimanagouda Patil

Texas A

Debanjan Chatterjee

Texas A

Debanjan Chatterjee, PhD, is a dedicated researcher specializing in natural products chemistry and pharmacological studies. He earned his B.Pharm in 2017, followed by an M.S. (Pharm) from the National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, in 2019... Read More →

Deepak Kumar Jha

Texas A

Vikas Dadwal

Texas A

I am experienced in phytochemical extraction and LC-MS metabolomics of pre and post-harvested fruits and vegetables. My research focuses on the development of plant-derived bioactive formulations and the assessment of their biological activity in vitro and in vivo. I am currently... Read More →

Tuesday July 29, 2025 4:30pm - 4:45pm CDT
Foster 1

Oral presentation, Postharvest 1

Subject Postharvest
Poster # csv

4:45pm CDT

PH 1 - Estimation of γ-aminobutyric acid and other amino acids as metabolic precursors in tomatoes using a novel unbuffered UPLC-FLD analytical approach

Tuesday July 29, 2025 4:45pm - 5:00pm CDT

Foster 1

Tomato metabolism changes in response to environmental conditions such as heat, drought, and soil salinity. This response causes changes in amino acid levels, which are directly related to enzyme activity, photosynthesis, and stress responses. For example, measuring the increase of proline during drought is a biomarker for stress conditions. Qualitative and quantitative analysis of amino acid levels requires precise chromatographic conditions in controlled settings. To accomplish consistent amino acid separation, individual chemical groups require adjustments to chromatographic parameters such as mobile phase composition, pH levels, column type and size, temperature, absorbance/emission wavelength, and gradient combination. This study developed a precise ultra-high performance liquid chromatography (UPLC) approach with a fluorescence detector (FLD) to quantify various amino acids, including γ-aminobutyric acid (GABA), using optimized concentrations of a weak acid (formic acid) and weak base (triethylamine) as modifiers in water and acetonitrile mobile phases, respectively. Buffers are commonly employed in amino acid chromatography; however, excessive usage can result in precipitation and salt accumulation, blocking the pumps. They may also cause pH shifts under high pressure and temperature conditions. Optimized chromatographic conditions improve amino acid separation and quantification. A mobile phase of 0.2% formic acid in water (A) and triethylamine in acetonitrile (B) produced the best results, with maximal separation at 55°C. The gradient began at 90% A and gradually decreased until minute 20, when it returned to the beginning conditions. The injection volume remained steady at 5 µL, with FLD detection peaking at 360 nm. Distinct peaks formed at a 1.0 mL/min flow rate while the pressure was maintained at 1300 psi. Calibration R² results were between 0.97 and 1.0, indicating technique correctness. Separation of real samples found 18 chemicals with retention time changes ranging from 0.01 to 0.05 min. Tomato fruit samples were procured from two developmental stages and amino acid levels were measured. This will provide a benchmark for distinguishing the tomato varieties based on their stress-resilient behavior. This work was partially supported by USDA-NIFA-2024-51181-43464, USDA-NIFA-AFRI 2023-67013-39616 through the Vegetable and Fruit Improvement Center and Institute for Advancing Health Through Agriculture of the Texas A

Speakers

Vikas Dadwal

Texas A

Co-authors

Bhimanagouda Patil

Texas A

Braulio Cervantes

Texas A

Debanjan Chatterjee

Texas A

Deepak Kumar Jha

Texas A

SANGEETA BALYAN

Texas A

Tuesday July 29, 2025 4:45pm - 5:00pm CDT
Foster 1

Oral presentation, Postharvest 1

Subject Postharvest
Funding Source This work was partially supported by USDA-NIFA-2024-51181-43464, USDA-NIFA-AFRI 2023-67013-39616 through the Vegetable and Fruit Improvement Center and Institute for Advancing Health Through Agriculture of the Texas A&M University.
Funding Option SCRI funded all or part of the research associated with this abstract

5:00pm CDT

PH 1 - Assessing postharvest outcome in d’Anjou pears sorted by a chlorophyll-carotenoid index based on hyperspectral images

Tuesday July 29, 2025 5:00pm - 5:15pm CDT

Foster 1

Large-canopy training systems commonly used in Washington pear orchards create sunlight exposure disparities among fruits. Pear ripening is influenced by sunlight exposure and variability contributes to non-uniform ripening postharvest outcomes. To enhance uniformity in fruit batches based on sunlight exposure, d ‘Anjou pears were sorted according to a newly adapted Chlorophyll-carotenoid index (Cri) based on Hyperspectral images. In September 2024, d’Anjou pears were harvested in three commercial orchards located across distinct growing regions in Washington and Oregon. Reflectance spectral information for each fruit was extracted from Hyperspectral images, and wavebands related to Chlorophyll and carotenoids (430, 662, 454, 549 nm) were subsequently used to calculate Cri values for each fruit. This index value allowed for sorting of fruit into batches under three sunlight categories: Low, Medium, and High. Fruit was kept in controlled atmosphere storage (3.0 % O2, 0.8 % CO2, 0 oC) and quality (Chlorophyll degradation (IAD), firmness (lb)), was studied after 4 months of storage plus 7 days at room temperature (20 oC). Fruit maturity indexes, at harvest, showed no differences between fruit categories. Chlorophyll degradation (IAD) on fruit surface showed that in two of the three orchards, low-exposure fruits exhibited lower values in comparison to high-exposure ones (P ≤ 0.01). Firmness values were significantly lower in high-exposure categories after cold storage and room temperature periods, landing at around 12 lbs and 3 lbs, respectively (P ≤ 0.01). No major differences in physiological disorders incidence between sunlight categories were observed. Further investigation needs to be conducted to determine how these categories behave in longer cold-chain storage scenarios.

Speakers

Oswaldo Gonzalez-Garcia

WSU TFRECT Postharvest Lab

Co-authors

Carolina Torres

Washington State University

Rene Mogollon

Washington State University

Tuesday July 29, 2025 5:00pm - 5:15pm CDT
Foster 1

Oral presentation, Postharvest 1

Subject Postharvest
Funding Source WSDA Specialty Crop Block Grant Program "Non-destructive sorting at harvest to improve pear cold chain outcome"

5:15pm CDT

PH 1 - Adapting a Hyperspectral Chlorophyll-Carotenoid Index (Cri) to Standardize Postharvest Outcomes in d ’Anjou Pears

Tuesday July 29, 2025 5:15pm - 5:30pm CDT

Foster 1

In Washington state, pears are typically cultivated on trees with large canopies, which results in different levels of sun exposure and, therefore, fruit maturity variability at harvest and postharvest. Hyperspectral reflectance imaging has been previously used to detect sun stress and predict sunscald risk through a chlorophyll-carotenoid index (Cri; 430, 662, 454, 549 nm) on apples. The objective of this work was to adapt a non-destructive sorting index to standardize groups of fruit with predictive postharvest outcomes throughout the cold chain and treatments. d ‘Anjou pears were harvested from different canopy positions (internal, external, and random) in three commercial blocks during 2023. Hyperspectral images (640 x 840 px; 400–1100 nm) were captured from the exposed and unexposed sides of the fruit at harvest. The reflectance information was then extracted and pre-processed with Savizky-Golay and Standard Normal Variate filters. With this information, the Cri was calculated for every fruit. Cri values ranged from 0.9 to 3.6 for fruit from external canopy positions and 1.1 to 3.8 for those from internal ones. The analysis of variance showed significant differences in Cri values across fruit sides and tree positions (p < 0.01). These findings support the viability of using the chlorophyll-carotenoid index to sort pears with different sun stress levels at harvest. Further research is needed to evaluate the consistency in response of the different fruit groups when submitted to different cold chain scenarios and postharvest treatments.

Speakers

Rene Mogollon

Washington State University

Co-authors

Carolina Torres

Washington State University

David Rudell

USDA-RS Wenatchee

Oswaldo Gonzales-Garcia

Washington State University

Tuesday July 29, 2025 5:15pm - 5:30pm CDT
Foster 1

Oral presentation, Postharvest 1

Subject Postharvest
Funding Source WSDA SPECIALTY CROP BLOCK GRANT PROGRAM; Project Title: Non-destructive sorting at harvest to improve pear cold chain outcome.

5:30pm CDT

PH 1 - Demonstration of the functionality of apple citramalate synthase on ester production in transiently transformed banana fruit

Tuesday July 29, 2025 5:30pm - 5:45pm CDT

Foster 1

Citramalate synthase is proposed to be the first committed step in the formation of branched chain esters in apples based on detailed biochemical, pharmacological, isotopic, and molecular data. However, the function of the full citramalate pathway, from the formation of citramalate to the formation of the branched chain esters containing 2-methylbutyl and 2-methylbutanoate moieties has not been tested using a gain of function model. In this work, we report on the transient transformation of ripening banana fruit with functional and non-functional alleles of MdCMS (MdCMS_1 and MdCMS_2, respectively) and report on the compounds induced by the addition of this gene. Banana do not produce appreciable levels of citramalate and make little to no 2-methylbutyl and 2-methylbutanoate containing esters. Following the transformation event, citramalate accumulated in banana transformed with MdCMS_1, but not MdCMS-2. Similarly, banana with the functional form of MdCMS produced modest levels of 2-methylbutyl acetate and 2-methylbutyl butanoate esters. Fruit transformed with MdCMS_1 also accumulated isoleucine as a by-product of the enhanced pathway throughput. Finally, there was a marked enhancement of propyl esters, likely a function of an increase in alpha-ketobutyrate, which is an intermediate in the citramalate pathway between citramalic acid and 2-methylbutyl and 2-methylebutnoate esters. The data provide the last necessary evidence for the conclusively documenting function of citramalate synthase as a functional pathway in apple useful for the production of aroma active branched-chain esters.

Speakers

Nobuko Sugimoto

University of Georgia

Co-authors

Ozge Horzum

Ankara University

Philip Engelgau

Michigan State University

Randolph Beaudry

Michigan State University

Dr. Randolph Beaudry, Professor, MSU Department of Horticulture (MSc, PhD, University of Georgia). His appointment is 50% MSU Extension and 50% AgBioResearch. His research program includes both regional and international projects and focuses on the physiology of plant responses to... Read More →

Tuesday July 29, 2025 5:30pm - 5:45pm CDT
Foster 1

Oral presentation, Postharvest 1

Subject Postharvest
Poster # csv

10:14am CDT

PH 2 - Oral Session

Wednesday July 30, 2025 10:14am - 10:15am CDT

Strand 12B

Presiding/Moderator

Jagjit Singh

Graduate Research Assistant (MS), Auburn University

Wednesday July 30, 2025 10:14am - 10:15am CDT
Strand 12B

Oral presentation, Postharvest 2

Subject Postharvest

10:15am CDT

PH 2 - Exploring the Effect of Postharvest Storage on Composition Changes in Selected Muscadine Grape (Vitis Rotundifolia Michx.) Cultivars

Wednesday July 30, 2025 10:15am - 10:30am CDT

Strand 12B

Muscadine grapes are native to the southeastern U.S. and are known for their unique flavor and aroma. Rapid postharvest deterioration of muscadine berries is a major barrier in market expansion. This study investigated the change in muscadine berries’ general composition over a four-week storage period. The vines were planted at the Chilton Research and Extension Center, Clanton, AL in a randomized complete block design with four single plant replications. Berries from the perfect-flowered cultivars ‘Hall’, ‘Paulk’, and ‘Southern Home’, and from the pistillate cultivars ‘Eudora’ and ‘Supreme’ (standard) were studied. Experimental vines were harvested on Aug. 2 and Sept. 4, 2024. One-pound clamshells were filled with berries collected from each experimental vine. Fresh samples (Week 0) were compared for berry quality changes occurring after 1, 3, and 4 weeks of cold storage at 4°C and 85% RH. After completing each storage period exposure, the berry samples were allowed to rest for 1 hour at room temperature. The change in berry weight and firmness was recorded after each storage treatment and 5 berry subsample was frozen at -80°C for later analysis of total soluble solids (TSS), titratable acidity (TA), TSS:TA ratio and pH. Our results indicate that the 4 Weeks storage period led to a significant weight loss of 11.3% in ‘Paulk’ and 7.6% in ‘Supreme’ berries in comparison to Week 0. It was found out that both cultivar and storage duration were accountable for the significant firmness reduction with ‘Paulk’ and ‘Supreme’ experiencing 51.4% and 46.2% reduction by Week 4 in storage. Titratable acidity increased significantly over time in all cultivars. The highest TA at Week 4 (0.67) was recorded for ‘Southern Home’, while ‘Paulk’ berries had the lowest TA (0.44), indicating strong cultivar effect (p < 0.0001). After the first week of storage, berries of ‘Hall’ were significantly sweeter than ‘Paulk’, while at Week 4, all cultivars had similar sweetness. Due to an increasing acidity trend, fruit pH decreased with increase in storage time exposure. Both cultivar and storage duration affected the berry pH. TSS:TA ratios varied significantly by cultivar and storage period duration with ‘Supreme’ maintaining its sweetness level throughout the four weeks of storage. Overall, the prolonged storage period resulted in significant firmness reduction and increased acidity with ‘Paulk’ exhibiting the highest reduction of berry firmness while ‘Supreme’ consistently maintained sweetness level over the 4-week period.

Speakers

Jagjit Singh

Graduate Research Assistant (MS), Auburn University

Co-authors

Bernardo Chaves-Cordoba

Auburn University

Edgar Vinson

Auburn University

Elina Coneva

Auburn University

Marlee Trandel Hayse

Auburn University

Melba Ruth Salazar Gutierrez

Auburn University

Wednesday July 30, 2025 10:15am - 10:30am CDT
Strand 12B

Oral presentation, Postharvest 2

Subject Postharvest
Funding Source USDA-SCBG-ADAI and Southern Region Small Fruit Consortium (SR SFC)

10:30am CDT

PH 2 - Insights into the Postharvest Quality of Brassica Leafy Greens Grown in the Southeastern United States

Wednesday July 30, 2025 10:30am - 10:45am CDT

Strand 12B

Brassica leafy greens are important vegetable crops in the Southern United States, where they are commercialized in whole and fresh-cut formats. Their consumption is associated with health benefits as these crops are rich in bioactive compounds with antioxidant activity. Several factors contribute to the postharvest quality of Brassica leafy greens. Preharvest seasonal variations associated with environmental variables can have a significant influence on shelf-life and quality maintenance and have been reported in various Brassica species. The effect of postharvest temperature management and mechanical stress induced by fresh-cut processing has also proven to be critical in organoleptic and nutritional quality; however, none of these factors have been systematically studied in collards, kale and turnip greens. This project aimed to address this knowledge gap by investigating the postharvest performance of whole and fresh-cut kale, turnip greens and collards during storage at different temperatures (2, 5 and 7°C) for up to 28 days in two growing seasons (fall and winter-spring). Cooling delays after harvest were imposed on some experiments. We also characterized the shelf-life of commercial and traditional collards ('landraces') commonly grown in the Southeast. Organoleptic (color, marketability scores, total soluble solids) and compositional (total chlorophyll, carotenoids, total polyphenols, lycopene, vitamin C and ammonia contents) were monitored during postharvest storage. Results revealed there was significant quality variation in fresh-cut kale, collards and turnip greens, which could attributed to genotypic differences and preharvest factors in each growing season. High shelf-life variability among commercial collards and landraces was observed. Moreover, postharvest storage at abusive temperatures accelerated quality deterioration in fresh-cut collards to a greater extent than in whole leaves. Collectively, these findings highlight that adjusting postharvest practices to seasonal shelf-life variations can contribute to minimizing food losses and optimizing produce supply chain performance. Furthermore, postharvest temperature regimes are critical in influencing the visual quality and nutrient retention of whole and fresh-cut collards during storage.

Speakers

Karin Albornoz

Assistant professor, Clemson University

Co-authors

Zenaba Abdissa

Clemson University

Wednesday July 30, 2025 10:30am - 10:45am CDT
Strand 12B

Oral presentation, Postharvest 2

Subject Postharvest
Funding Source South Carolina Department of Agriculture, NIFA USDA

10:45am CDT

PH 2 - Lettuce Postharvest Quality in Response to The Increase of Phosphorus Fertilizer

Wednesday July 30, 2025 10:45am - 11:00am CDT

Strand 12B

Florida ranks third in the United States for lettuce production with approximately 90% of commercial lettuce cultivated on organic soils in southern Florida. These organic soils require phosphorus (P) inputs to sustain economic production and ensure lettuce shelf-life. Lettuce shelf-life depends on quality factors such as firmness, appearance, color, texture, decay, discoloration, and wilting. Optimal P fertilizer management is necessary to improve yield, market quality, and ensure postharvest quality (shelf-life). Over-fertilization can reduce quality, while deficiencies can limit yield and shelf life. Therefore, the objective of this research was to understand how different rates of P affect the lettuce shelf-life across four cultivated morphological types. Two field trials were conducted at the Everglades Research and Education Center in Belle Glade, FL, during the lettuce growing seasons (spring, fall, and winter). Experiments were set as a split-plot designed in which P fertilizer rates (0, 48, 97, 150, 195, and 210 lbs P2O5 acre-1) were considered as the main plot and four lettuce types (romaine, iceberg, butterhead, and leaf) as the subplot. Ammonium polyphosphate (11-37-0) was used as the source of P fertilizer. Shelf-life was evaluated over 10 days at 15 °C and 90% RH using visual ratings of 9 (excellent) to 1 (poor) following the protocol for an accelerated shelf-life testing. The estimated shelf-life was considered as the number of days when lettuce reached an acceptable appearance on the rating scale of ≥5 and multiplied by a factor of 2 (2-fold factor proportional to the deterioration rate). The results indicate varying responses to P fertilizer application in shelf-life that were significantly morphological-type dependent. Overall, leaf lettuce had the shortest shelf-life and iceberg lettuce had the longest shelf-life. Butterhead had an acceptable estimated shelf-life rating of 5 at 24 days at 210 lbs. P2O5 acre-1 while romaine and leaf had a shelf-life rating of 5 at 22 and 21 days at 210 lbs. P2O5 acre-1, respectively. In addition, crisphead had an acceptable estimated shelf-life rating of 5 above 35 days at 150 lbs. P2O5 acre-1. However, an acceptable shelf-life was maintained at 48, 150, or 195 lbs. P2O5 acre-1 in iceberg lettuce over 30 days. Together these results demonstrate that there is no effect of increasing the rate of P2O5 acre-1 to maintain economic yields on the lettuce shelf-life. Rather, shelf-life quality increases with P inputs.

Speakers

German Sandoya Miranda

Associate Professor, University of Florida EREC

Co-authors

Adrian Berry

University of Florida

Jairo Arcos Jaramilo

University of Florida EREC

Jesse Murray

University of Florida EREC

Shabnam Sadeghibaniani

University of Florida EREC

Steven Sargent

University of Florida/IFAS

Professor and Extension Postharvest Specialist

Wednesday July 30, 2025 10:45am - 11:00am CDT
Strand 12B

Oral presentation, Postharvest 2

Subject Postharvest
Poster # csv

11:00am CDT

PH 2 - Fruit Maturity Highly Affects Controlling Necrotic Peel Disorders By Mediating Major Metabolisms in Cold-stored Hardy Kiwifruit (Actinidia arguta)

Wednesday July 30, 2025 11:00am - 11:15am CDT

Strand 12B

The incidence of necrotic peel disorders during cold storage is a severe CI symptom observed in hardy kiwifruit, impacting fruit visual quality. This study focuses on understanding the mechanisms of necrotic peel disorder in ‘Daebo’ hardy kiwifruit cultivar during cold storage. This research aimed to investigate the effects of different soluble solids content (SSC)-based fruit maturity at harvest on the severity of peel disorder after storage and to present the associated biochemical alteration using integrated transcriptomic, antioxidant, and lipidomic analyses. The fruit of ‘Daebo’ hardy kiwifruit cultivar harvested at various SSC levels, including 5.5%, 6.1%, and 7.2%, were cold-stored for upto four weeks. Fruit harvested at 5.5% SSC exhibited the highest severity of necrotic peel disorder, accompanied by significant weight loss and elevated reactive oxygen species (ROS) levels. The enhanced activities of antioxidant scavenging enzymes, such as superoxide dismutase and ascorbate peroxidase, were observed, indicating the response of fruit to oxidative stress. However, lower enzymatic activities of dehydroascorbate reductase and glutathione reductase were insufficient to restore the ascorbic acid-glutathione cycle. In contrast, the 7.2% SSC fruit contained higher concentrations of phenolic compounds, suggesting their role as natural antioxidants in mitigating oxidative damage. Additionally, lipid analysis revealed increased levels of phosphatidylcholine and fatty acids during fruit maturation, which are crucial for membrane stability. Notably, the differences in phosphatidic acid concentrations between SSC levels indicated its potential role in ROS scavenging. Overall, this study elucidates the biochemical mechanisms contributing to necrotic peel disorder in hardy kiwifruit during cold storage, highlighting the importance of SSC at harvest in managing fruit quality. These findings can comprehensively understand necrotic peel disorder and fruit maturity in hardy kiwifruit.

Speakers

Hyowon Park

Chung-Ang University

Co-authors

Jinwook Lee

Chung-Ang University

Uk Lee

National Institute of Forest Science

Yonghyun Kim

National Institute of Forest Science

Wednesday July 30, 2025 11:00am - 11:15am CDT
Strand 12B

Oral presentation, Postharvest 2

Subject Postharvest
Funding Source This work was financially supported by a grant (Grant Number FP0802-2022-02-2025) from the National Institute of Forest Science (NIFoS) in the Republic of Korea.

11:15am CDT

PH 2- Investigate the Molecular Mechanisms of Postharvest Senescence in Vegetables

Wednesday July 30, 2025 11:15am - 11:30am CDT

Strand 12B

Postharvest longevity of perishable produce remains a challenge in the global fresh market supply chain. Postharvest longevity is determined by the rates of ripening and senescence, which are influenced by harvest time and storage conditions. Ripening and senescence are predominantly regulated by ethylene, which produces a plethora of metabolic effects within the harvested produce, leading to physiological and developmental changes during postharvest. Broccoli (Brassica oleracea L. var. italica) are prone to yellowing and wilting due to the relatively high respiration rate and tissue senescence during postharvest handling, transportation, and storage, which greatly affects the quality and reduces market value that led to the problem of food waste and loss. Broccoli florets treated with hydrocooling, 1-MCP (ethylene inhibitor) and controlled atmosphere (CA) can delay the senescence. However, little is known about the mechanisms on how those treatments worked at the molecular level. Here, we combined a physiological, biochemical, and genomics analyses on the postharvest broccoli and identified a core gene regulatory network governing senescence-associated developmental events, ethylene-regulated signaling pathways, and activation of stress responses. Additionally, we developed genome-editing toolkits by CRISPR/Cas9 system to understand deterioration of broccoli as well as through machine learning approaches to aid development of an innovative and easy-to-use accessibility tool to accurately estimate the freshness of produce. The findings give insights into ethylene biosynthesis and signal transduction at the tissue-specific level in broccoli and provide guidance on how to extend broccoli shelf life and reduce its economic losses, which also generate genetics and molecular recourses for marker-assistant breeding and expand the general scientific knowledge of regulating senescence of Brassicaceae family.

Speakers

Tie Liu

University of Florida

Wednesday July 30, 2025 11:15am - 11:30am CDT
Strand 12B

Oral presentation, Postharvest 2

Subject Postharvest
Poster # csv

11:30am CDT

PH 2 - “Correlation Between Boron Leaf Damage and Fresh Yield in Saline-Sodic Soils”

Wednesday July 30, 2025 11:30am - 11:45am CDT

Strand 12B

Most of the world's pistachios are grown in saline-sodic soils with soil boron (B) levels over the 2 ppm suggested for most trees. As a resulting symmetrical leaf edge necrosis produced by B accumulation, “B toxicity”, is common and regarded as damaging to leaf photosynthetic capacity. This study was carried out in a 8-year-old pistachio orchard with field-budded Pistacia vera cv. ‘Golden Hills’ on cloned P. atlantica x P. integerrima, UCBI rootstocks, spaced at 18 x 20 feet, 121 trees per acre. The soil was a silty clay loam saline-sodic Cerrini complex with salinity ranging from 3 to 15dS/m, pH 7.5 to 8.2, boron levels of 3 to 12 ppm and soil sodium levels ranging from 16 to 130 meq/l (370 to 3000 ppm). High soil and water B levels will produce increasingly higher scion leaflet B leaf symptoms ranging from a slender marginal necrosis to almost complete necrosis. We analyzed the relationships among soil B, leaf B, percentage of damaged leaf surface and marketable yield. Our results a demonstrated a strong negative correlation of yield as a function of soil B. As soil B levels increased yield decreased; r = - 0.705, p < 0.001. However, both leaf B levels and % leaf damage had had weak, insignificant relationships with soil B levels. As soil B increased leaf B levels and the percentage of damaged leaf areas did not increase. However, there was a moderately positive relationship between leaf boron levels and leaf damage; r = 0.50, P

Speakers

MARTA INES SALUDES ZANFANO

Subs. Professor, Universidad de Salamanca

Marta I. Saludes Zanfaño, a passionate biologist who’s revolutionizing sustainable farming with a special knack for pistachio cultivation and organic weed control. Based at the University of Salamanca, Spain, as a graduate member of the Chemical Sciences and Technology group, she... Read More →

Co-authors

Blake L Mccullough-Sanden

University of California

CLAY BECK

MARICOPA ORCHADS

DONALD WILLIAMS

UNIVERSITY OF FRESNO

Giulia Marino

UC Davis

JOSEPH COELHO

Maricopa Orchards

Louise Ferguson

UC DAVIS

MAE CULUMBER

University of California

Mukesh Mehata

University of California, Davis

Wednesday July 30, 2025 11:30am - 11:45am CDT
Strand 12B

Oral presentation, Postharvest 2

Subject Postharvest
Poster # csv
Funding Source California Pistachio Research Board
Funding Option OREl or ORG funded all or part of the research associated with this abstract

11:45am CDT

PH 2 - Optimizing Mechanical Harvesting of Vidalia Onions Using Impact Sensing Technology to Minimize Bruise Damage

Wednesday July 30, 2025 11:45am - 12:00pm CDT

Strand 12B

Short-day onions such as Vidalia are vital in warmer climates, but their delicate skins make them prone to an average of 8% bruise damage during mechanical harvesting. As a result, manual hand harvesting remains the preferred method despite its high cost of $3,951/hectare for labor, according to the 2019 Onion Irrigated Budget (University of Georgia). Addressing issues of mechanical harvesting could offer a more cost-effective alternative while solving the labor shortage problem. This study aimed to evaluate the bruise tolerance of five Vidalia varieties (Vidora, Sweet Magnolia, Sapelo, Red Maiden, and Monjablanca) under different impact conditions and identify the specific sections of mechanical harvesters that contribute to bruising. Identifying the most bruise-tolerant varieties can guide growers in selecting onions better suited for mechanical harvesting, reducing labor costs and postharvest losses and by understanding which sections of the harvester cause the most damage, modifications can be made to reduce bruising. Controlled pendulum tests were conducted to simulate onion-to-surface impacts, using onions embedded with Impact Recording Devices (IRDs) to measure impact forces at two maturity stages (80% tops down and one week after 80% tops down) and two drying durations (0 and 7 days). Drop heights were selected based on bruise damage results for Vidora, with two levels for each surface type: 10 cm and 30 cm for flat surfaces, and 30 cm and 55 cm for padded surfaces. A total of 320 impacts were recorded. To identify the most bruise-prone sections of the harvester, 23 field trials were conducted using a Top Air Harvester, with IRDs embedded within onions and placed on field, to capture real-time impact data. The Top Air Harvester, consisting of a collecting belt, elevator, sorting belt, and conveyor, transferred onions to the bulb collection truck within 36 seconds. Early results for Vidora variety indicate that bruising severity increases with higher drop heights, on flat surfaces, while padded surfaces significantly reduce damage. Testing all five varieties will provide a comprehensive profile of bruise tolerance, helping growers select varieties better suited for mechanical harvesting, potentially reducing labor costs. Initial analysis of field trials revealed that the conveyor-to-bin transition generated the highest impact forces, significantly contributing to bruising. These preliminary results indicate the need for design improvements in this section to reduce impact damage and enhance mechanical harvesting efficiency. Further testing will validate these findings and guide the development of improved mechanical harvesting practices.

Speakers

Aleena Rayamajhi

University of Georgia

Co-authors

MD Sulton Mahmud

University of Georgia

Wednesday July 30, 2025 11:45am - 12:00pm CDT
Strand 12B

Oral presentation, Postharvest 2

Subject Postharvest
Poster # csv
Funding Source USDA NIFA
Funding Option SCRI funded all or part of the research associated with this abstract

1:00pm CDT

PH 1 - Alternative Oxidase Interacts with SNF1 Kinase to Modulate Energy Metabolism During Pear Fruit Ripening

Wednesday July 30, 2025 1:00pm - 1:45pm CDT

Empire AB

Alternative Oxidase Interacts with SNF1 Kinase to Modulate Energy Metabolism During Pear Fruit Ripening Adwaita Prasad Parida and Amit Dhingra1 Correspondence: Amit Dhingra, Professor, Department of horticultural sciences, A

Speakers

Adwaita Parida

Texas A

Co-authors

Amit Dhingra

Texas A

Wednesday July 30, 2025 1:00pm - 1:45pm CDT
Empire AB

Poster, Postharvest 1

Subject Postharvest
Funding Source Texas A&M University and Texas A&M AgriLife Startup Funding to the Dhingra Genomics and Biotechnology Lab

1:00pm CDT

PH 1 - Effect of Atmospheric Modification on the Postharvest Shelf-Life of Pawpaw (Asimina triloba)

Wednesday July 30, 2025 1:00pm - 1:45pm CDT

Empire AB

Pawpaw (Asimina triloba), a North American tree fruit, belongs to the Annonaceae family and is the only temperate member of this family. Pawpaw is emerging as an alternative high-value niche crop for small farms in Kentucky and surrounding states; however, due to its highly perishable nature, the marketing window for fresh fruit is currently limited. Pawpaw fruit can only be stored for 3-5 days at room temperature or for about 1 month under cold storage at 4 °C. The objective of this study was to examine the efficiency of modified atmosphere with plastic packaging in cold storage to increase the shelf-life of pawpaw fruit and its impact on the quality attributes of fruit. This experiment was conducted with fruit from the pawpaw cultivar Sunflower. Fruits were harvested and stored in three treatments of modified atmosphere in 2.5-gallon plastic container bags, with the treatments of 1) plastic bag with ambient air (Control), 2) plastic bag with an additional ethylene absorber, and 3) plastic bag with modified atmosphere of low oxygen and high carbon dioxide gas mix (12% O2 and 10% CO2 and balance nitrogen). There were three replicate bags per treatment with each bag containing three fruits. Fruits were stored at 6 °C. Data on gas composition in bags and quality parameters of fruit such as firmness, brix, color (L*, a*, b*), and weight were taken on 5, 10, 20, 40, and 80 days of storage. The ethylene absorber and gas mix treatments maintained lower ethylene concentrations inside the bags as compared to the control. The gas mix treatment resulted in reduced fruit weight loss and maintained the lightness of fruit pulp significantly. However, firmness in all fruits significantly declined after 20 days of storage in all treatments. These data suggest that the ethylene absorber and gas mix treatments during cold storage have at least some potential for extending shelf-life of pawpaw, with additional modifications or harvest times.

Speakers

Kshitij Shahi

Kentucky State University

Co-authors

Brent Arnoldussen

University of Kentucky

Jeremy Lowe

Kentucky State University

Kirk Pomper

Kentucky State University

Dr. Kirk W. Pomper is the Professor of Horticulture in the College of Agriculture, Community, and the Sciences at Kentucky State University in Frankfort, Kentucky. As Horticulture Research Leader, his program is focused on research and Extension efforts toward developing pawpaw as... Read More →

Sheri Crabtree

Kentucky State University

Wednesday July 30, 2025 1:00pm - 1:45pm CDT
Empire AB

Poster, Postharvest 1

Subject Postharvest
Funding Source USDA Evans Allen Grant Number KYX--10-17- 63P

1:00pm CDT

PH 1 - Investigations of apple lenticel breakdown and other superficial disorders

Wednesday July 30, 2025 1:00pm - 1:45pm CDT

Empire AB

Several apple cultivars are susceptible to lenticel breakdown including but not limited to ‘Honeycrisp’, ‘Red Delicious’, ‘Gala’, and ‘SweeTango’. ‘Honeycrisp’ in particular has received considerable scrutiny by apple growers and packers due to its low percentage of packable fruit. ‘Honeycrisp’ in Michigan are put into storage with little to no disorders and, in 3-5 months, are pulled out of storage achieving less than 50% pack-outs of quality fruit in severe cases. These low pack-outs are a result of internal disorders, a physiological disorder ‘bitter pit’, lenticel breakdown, advanced decay, and some unknown light brown spotting that can be similar or smaller in size than lenticels. Investigations into the mechanisms behind these various ‘spots’ and discriminating between them is an essential first step in understanding the disorders and the discovery of solutions for growers and storage operators. In this study, three preliminary assessments were made to resolve the ambiguity behind lenticel breakdown and associated ‘spots’: 1) apple lenticels were imaged by light and scanning electron microscopy and characterized, 2) ‘Honeycrisp’ and ‘SweeTango’ apples were wrapped in paper and mesh bags on the tree as a field chemical spray exclusion assessment, and 3) a preliminary look at the microbiome of healthy and unhealthy lenticels. The latter effort revealed that ‘Alternaria’ species dominate the fungal community of unhealthy lenticels.

Speakers

Alexander Engelsma

Michigan State University

Co-authors

Emily Lavely

Michigan State University Extension

Nikki Rothwell

Michigan State University Extension

Nobuko Sugimoto

Michigan State University

Ozge Horzum

Michigan State University

Randolph Beaudry

Michigan State University

Wednesday July 30, 2025 1:00pm - 1:45pm CDT
Empire AB

Poster, Postharvest 1

Subject Postharvest
Funding Source Michigan Apple Committee and Project GREEEN

1:00pm CDT

PH 1 - Physiological And Metabolic Responses Of Maturity Levels And Postharvest Treatments In Cold-stored Interspecific ‘Greens

Wednesday July 30, 2025 1:00pm - 1:45pm CDT

Empire AB

The interspecific pear cultivar ‘Greensis’ has become a highly demanded pear cultivar due to its unique flavor of sweetness, crispness and juiciness. This study evaluated the postharvest storage quality of ‘Greensis’ pear at two maturity levels, treated with the 1 µL L-1 1-methylcyclopropene (1-MCP), pre-storage conditioning (PSC), and the combination treatment of 1-MCP and PSC before long term cold storage at 0.5 °C for 6 months. Both the incidence and severity of physiological disorders, such as cortex and core browning, were significantly reduced in PSC treatments, meanwhile, the severity levels of cavity were notably lower in treated fruit compared to untreated (control) fruit. Among the targeted metabolites, soluble carbohydrates and organic acids particularly, sucrose and shikimic acid were lower in mature fruit than immature fruit. Moreover, the contents of glucose, fructose, malic acid and shikimic acids were higher in PSC treated fruit than the other treatments especially in mature fruit. The branched-chain amino acids, including isoleucine and leucine, glutamic acid and phenylalanine, in all treatments were lower in immature fruit, meanwhile, methionine was higher in mature fruit. Additionally, in immature fruit, the contents of asparagine, serine, threonine and proline in the combination treatment of 1-MCP and PSC were higher than the other treatments. In addition, the phenolic contents of all treated fruit were higher in immature than mature fruit especially in chlorogenic acid, arbutin, caffeic, p-coumaric acid, and gallic acid after long term cold storage. Overall, these results suggested that the higher accumulation of phenolic compounds and specific amino acid contents in immature fruit play as a defense mechanism and enhances cold stress tolerance during long-term cold storage. Furthermore, PSC treatments effectively maintain the postharvest fruit quality by reducing the physiological disorders in cold stored ‘Greensis’ pear.

Speakers

Theintthandar Latt

Chung Ang University

PhD candidate at Postharvest Physiology Laboratory, Chung-Ang University.

Co-authors

Hyowon Park

Chung-Ang University

Jinhee Lee

National Institute of Horticultural and Herbal Science

Jinwook Lee

Chung Ang University

Jiwon Park

Chung Ang University

Joohyuk Jo

Chung Ang University

Si-Eun Byeon

Chung-Ang University

Wednesday July 30, 2025 1:00pm - 1:45pm CDT
Empire AB

Poster, Postharvest 1

Subject Postharvest
Poster # csv

1:00pm CDT

PH 1 - Postharvest Handling and Shelf-Life Evaluation of Three Blackberry Cultivars Under Controlled Storage Conditions

Wednesday July 30, 2025 1:00pm - 1:45pm CDT

Empire AB

Blackberry berries are highly perishable fruits, requiring effective postharvest management to maintain quality during storage. This study investigates the shelf-life and postharvest physiology of three blackberry cultivars ‘Ponca’, ‘Freedom’, and ‘Osage’—stored at 0°C for 0 to 7 days and 5°C for 8 to 16 days. Key parameters measured include red drupelet reversion, leakiness, weight loss, acidity (citric, malic, tartaric acid), pH, Brix content, anthocyanin, and antioxidant content. Fresh blackberry fruits of three different cultivars were collected from a commercial garden and stored in 6 oz clamshell boxes under controlled conditions. Physiological parameters such as weight loss, red drupelet reversion, and leakiness were evaluated at 0, 7, 12, and 16 days of storage. For chemical analysis, an additional 6 oz clamshell box for every sample was stored at -40°C at 0, 7, 12, and 16 days to assess acidity, Brix content, anthocyanin, and antioxidant. Results indicate significant varietal differences in postharvest stability. ‘Freedom’ exhibited the highest red drupelet reversion and leakiness, with a steady decline in acidity over time, suggesting rapid deterioration. ‘Osage’ maintained the most stable postharvest quality, showing the lowest red drupelet reversion and highest acidity, which may contribute to improved storage potential. ‘Ponca’ demonstrated moderate stability but exhibited a sharp increase in leakiness and red drupelet reversion at later stages, indicating postharvest instability. Weight loss data revealed that ‘Freedom’ experienced the highest weight reduction, while ‘Ponca’ and ‘Osage’ exhibited greater stability over the storage period. Acidity levels varied significantly among cultivars, with ‘Osage’ retaining the greatest citric, malic, and tartaric acid concentrations, potentially enhancing shelf stability. ‘Freedom’ exhibited the lowest acidity, affecting taste and preservation. pH trends revealed that ‘Freedom’ lost acidity fastest, while ‘Ponca’ maintained stable acidity, making it more suitable for extended storage. These findings highlight the need for cultivar-specific postharvest strategies. While ‘Osage’ appears to have better natural postharvest qualities, ‘Ponca’ and ‘Freedom’ may require optimized storage conditions to minimize quality loss. This study provides valuable insights for improving blackberry storage, reducing postharvest losses, and extending marketability.

Speakers

Nurjahan Sriti

University of Florida

Co-authors

Guodong Liu

University of Florida

Jeffrey Williamson

University of Florida

Steven Sargent

University of Florida/IFAS

Professor and Extension Postharvest Specialist

Zhanao Deng

University of Florida

Wednesday July 30, 2025 1:00pm - 1:45pm CDT
Empire AB

Poster, Postharvest 1

Subject Postharvest
Poster # csv

1:00pm CDT

PH 1 - Preharvest Ethylene Regulators and their Impact on Postharvest Fruit Quality of ‘Honeycrisp’ Apples Grown in the Mid-Atl

Wednesday July 30, 2025 1:00pm - 1:45pm CDT

Empire AB

Reduced fruit quality throughout cold storage is a major stakeholder-identified factor limiting production and marketability of the profitable apple ‘Honeycrisp’ in the Mid-Atlantic. ‘Honeycrisp’ is known to be a chilling sensitive cultivar when cooled immediately after harvest, therefore fruits are submitted to a postharvest conditioning treatment (10ºC for 7 days) prior to cold storage (3ºC). However, conditioning exacerbates the expression of bitter pit, rendering the fruit unmarketable. Moreover, maturity at harvest is a critical factor affecting apple fruit quality as well as susceptibility to chilling stress. Ethylene, the primary hormone related to hastening fruit maturity, can be regulated via the use of preharvest ethylene regulators. We aimed to characterize and compare the effects of different preharvest ethylene regulators on ‘Honeycrisp’ fruit maturity, quality and chilling sensitivity during postharvest. Three preharvest ethylene regulators with different modes of action were applied based on manufacturer’s recommendations, including 1- methylcyclopropene (1-MCP, Harvista), aminoethoxyvinylglycine (AVG, Retain), Ethephon (Ethrel) and a control. Fruits were harvested at two maturity stages: at the anticipated commercial harvest (CH) and one week after CH (CH 1). After harvest, in each case, fruit were submitted to conditioning (10ºC for 7 days) and then stored at 3ºC. Fruit from all 8 treatments were evaluated at harvest, and after 8, 16 and 24 weeks of storage at 3ºC, followed by a shelf-life period (7 days at 20ºC). Our results show that preharvest ethylene regulator treatments impacted fruit maturity and quality of ‘Honeycrisp’ apples during storage. Ethylene production was reduced in 1-MCP and AVG treated fruit, with the latter showing the lowest values throughout storage during both harvest dates. Concurrently, 1-MCP and AVG treated fruits displayed a higher flesh firmness as well as a greener background color (as indicated by higher IAD values) compared to Ethephon- treated and control fruit. Skin blush was negatively affected by 1-MCP and AVG applications, which were maintained throughout postharvest, with AVG-treated fruit exhibiting the significantly lower values. Effects on starch pattern indices and soluble solids contents were inconsistent. Chilling sensitivity, through the presence of soft scald, was not observed, but 1-MCP treated fruit presented the highest bitter pit incidence, followed by AVG-treated fruit, while Ethephon and control fruit displayed the lowest. This study contributes to understand how preharvest ethylene modulation influences ‘Honeycrisp’ apple maturity and quality throughout storage.

Speakers

Md Shipon Miah

University of Maryland - College Park

Co-authors

Macarena Farcuh

University of Maryland

Wednesday July 30, 2025 1:00pm - 1:45pm CDT
Empire AB

Poster, Postharvest 1

Subject Postharvest
Funding Source USDA NIFA AFRI GRANT13712074

1:00pm CDT

PH 1 - Red Drupelet Reversion and Consumer Preference of Four Blackberry Cultivars Grown in Georgia

Wednesday July 30, 2025 1:00pm - 1:45pm CDT

Empire AB

Blackberry (Rubus spp.) production in Georgia is valued at $19.9 million annually with approximately 1,900 planted acres, mostly concentrated in the southern part of the state. Blackberries have been increasingly planted in Georgia as a dynamic alternative crop that can diversify and support blueberry growers’ income. The harvest season is short, starting in mid-May and ending mid-July. The planted genotypes are mainly from other Southeastern breeding programs often with little to no testing on their suitability for the local growing conditions. Four University of Arkansas-bred cultivars – ‘Caddo,’ ‘Osage,’ ‘Ouachita,’ and ‘Ponca,’ were selected with a goal to identify the most appropriate cultivar for production in Georgia climatic conditions. Blackberries were hand-harvested, field-packed, placed in cold storage for up to 21 days, and evaluated over a two-year harvest period from a commercial field in Holt, GA (31.5957˚N, 83.1507˚W). Red Drupelet Reversion (RDR) is a major postharvest disorder where fully ripe, black drupelets revert to red color after harvest. Assessments for RDR incidence were conducted immediately after harvest and every seven days, along with measurements of berry physicochemical traits. Consumers' taste panels were conducted a day after harvest. A high incidence of RDR was quantified at harvest and after storage for ‘Ouachita,’ followed by ‘Ponca,’ ‘Caddo’ and ‘Osage.’ In addition, the panelists favored ‘Caddo’ blackberries, while ‘Ouachita’ was the least preferred cultivar. Appropriate preharvest and postharvest practices, in combination with timely, gentle harvests should be employed to decrease RDR incidence and maintain fruit quality.

Speakers

Vinicius Fernandes Araujo

University of Georgia

Co-authors

Angelos Deltsidis

University of Georgia

Ramsey Corn

University of Georgia

Zilfina Rubio

University of Georgia

Wednesday July 30, 2025 1:00pm - 1:45pm CDT
Empire AB

Poster, Postharvest 1

Subject Postharvest
Poster # csv

1:00pm CDT

PH 1 - Sweetpotato Peel Nanoparticle Coatings Reduce Postharvest Deterioration

Wednesday July 30, 2025 1:00pm - 1:45pm CDT

Empire AB

Edible nanoparticle coating materials were developed from sweetpotato peel tissue combined with sodium alginate and tested for their efficacy in reducing sweetpotato and potato postharvest deterioration. The bio-based nanoparticle coatings applied as thin films to the surface of sweetpotato roots and potato tubers reduced postharvest weight loss and respiration rate. The sweetpotato peel-based nanoparticle coating formulations included 1% and 2% sodium alginate. To enhance the structural integrity of the coatings, they were cross-linked by immersion in a 1% calcium chloride solution. The crosslinked formulations significantly outperformed non-crosslinked coatings and uncoated samples by minimizing weight loss (to below 2.0%–4.0% versus 3.5%–6.5% in controls) and decreasing respiration rates (to 5-13 mL CO₂/kg·h versus 7-20 mL CO₂/kg·h in controls) over extended storage periods. The enhanced performance is attributed to the formation of a dense, mechanically robust coating matrix. Sweetpotato peel tissue nanoparticles combined with sodium alginate and crosslinked with calcium chloride offer promise as sustainable coating materials for reducing fresh produce postharvest deterioration

Speakers

Ragab Abouzeid

Louisiana State University

Co-authors

David Picha

Louisiana State University

Qinglin Wu

Louisiana State University

Wednesday July 30, 2025 1:00pm - 1:45pm CDT
Empire AB

Poster, Postharvest 1

Subject Postharvest

1:00pm CDT

PH 1 - The Difficulty of Degreening Florida Grapefruit with the “Greasy Green” Disorder

Wednesday July 30, 2025 1:00pm - 1:45pm CDT

Empire AB

Fresh grapefruit consumers are trained to expect vivid yellow-orange peel color, depending on the variety, even though peel color has little to do with internal maturity or quality. The greasy spot rind blotch disease has been in Florida for many years, ascribed to a fungal pathogen called Zasmidium citri-griseum (previously named Mycosphaerella citri). Besides causing defoliation, it also mars the peel with tiny black specks that cause the rind to remain green, even after degreening. The spots can coalesce into black patches in extreme cases, sometimes called “pink pitting” or greasy spot rind blotch. Growers had this disease under good management, but within the past five years, fruit with similar symptoms started appearing as early as November, when nighttime temperatures are low, and peel color should improve instead of regreening. The symptoms are like greasy spot rind blotch, but there are few to no symptoms on the leaves of the same trees. Thus, the industry generally refers to the disorder as “greasy green” until a more definitive identification of the causal agent and disease development is determined. In a 2021 grower survey, 89% of respondents experienced the disorder to some extent, with packers reporting losses ranging between $20,000 and $1.7 million. There was no consensus among growers and packers regarding the cause of greasy green or the factors contributing to the problem. While studies are underway to determine if the disorder is indeed related to greasy spot rind blotch, studies were initiated to determine if affected fruit could be degreened effectively, as many packers often ended up abandoning degreening attempts on affected fruit and not using them for the fresh market. Our tests found that even after degreening (5 ppm ethylene at 27oC) red and white grapefruit for up to 5 days, their peel color still was not acceptable (

Speakers

Mark Ritenour

University of Florida - Indian River REC

Co-authors

Cuifeng Hu

University of Florida

Eva Mulandesa

University of Florida

Liliana Cano

University of Florida

Megan Dewdney

University of Florida

Monty Myers

University of Florida

Wednesday July 30, 2025 1:00pm - 1:45pm CDT
Empire AB

Poster, Postharvest 1

Subject Postharvest
Funding Source Citrus Research and Development Foundation, Inc.

12:30pm CDT

Fruit, Vegetable, and Edible Crops Collaboration Session

Thursday July 31, 2025 12:30pm - 1:30pm CDT

Collaboration Center, Empire AB

A forum for discussion of potential collaborations with regards to fruit, vegetable, and edible crops – i.e. citrus, breeding, production systems, postharvest, pomology, crop management, viticulture, etc.

Thursday July 31, 2025 12:30pm - 1:30pm CDT
Collaboration Center, Empire AB

Hort Theater & Collaboration Center, Collaboration Center

Subject Citrus Crops, Postharvest, Pomology, Produce Quality Safety and Health Properties, Viticulture and Small Fruits, Horticulture Industry, Organic, vegetable Breeding, Vegetable Crops Management, Temperate Tree Nut Crops, Fruit Breeding, Commercial Horticulture, Growth

1:00pm CDT

PH 2 - Analyzing Aflatoxin Risks Through Molecular Detection of A. flavus Strains and Co-Infection Patterns In Peanut Seeds

Thursday July 31, 2025 1:00pm - 1:45pm CDT

Empire AB

Aspergillus flavus is an airborne fungus that can contaminate agricultural commodities very rapidly, including grains and nuts. This pathogen causes aflatoxin contamination in peanuts, which leads to significant crop losses and their quality, particularly in storage conditions. Accurately identifying toxin and non-toxin producing A. flavus isolates is important in terms of effective management because traditional approaches have limitations such as being less effective and time-consuming. To address this problem, we developed molecular tools to differentiate toxigenic and non-toxigenic A. flavus isolates. We identified A. flavus isolates through morphological and species-specific primer (FLA1/FLA2). Also, to characterize toxigenic and non-toxigenic A. flavus isolates, we employed a combination of approaches such as RT-PCR, RT-qPCR, and aflatoxin measurement, focusing on four genes (AflD, AflQ, AflP, AflR) from the aflatoxin biosynthesis gene cluster with primer optimization. In addition, research on the co-infection pattern of aflatoxin contamination on peanut seeds during storage conditions is limited. To address this, we collected peanut isolates from different seed lots and performed ITS sequencing to understand the pattern of microbial communities on peanut seeds during aflatoxin contamination. Regarding aflatoxigenic and non-toxigenic A. flavus detection, different gene expression patterns were observed among four AFs biosynthesis genes. However, by combining gene expression patterns, quantification and AFs production, we differentiated toxin and non-toxin producing A. flavus isolates. These results indicated the efficacy and specificity of these molecular tools, which could be helpful for developing good molecular markers for distinguishing toxigenic and atoxigenic isolates and to manage A. flavus contamination in peanut seed lots. Our co-infection results from peanut seed lots during multiple years observed the infection of diverse microbiota along with A. flavus, which indicates other microbes co-infect with A. flavus infection. This co-infection could trigger aflatoxin production in peanut seeds. Therefore, this approach offers novel insights into peanut seed-associated microbiomes, co-infection and aflatoxin production, shedding light on the correlation between the role of microbial communities and aflatoxin contamination.

Speakers

Md Mostafa Masud

Alcorn State University

Co-authors

Emran Ali

Alcorn State University

Sumyya Waliullah

Alcorn State University

Thursday July 31, 2025 1:00pm - 1:45pm CDT
Empire AB

Poster, Postharvest 2

Subject Postharvest
Funding Source USDA-NIFA

1:00pm CDT

PH 2 - Assessing Postharvest Texture Variations in Rabbiteye and Southern Highbush Blueberries Grown in Alabama

Thursday July 31, 2025 1:00pm - 1:45pm CDT

Empire AB

Blueberry firmness is a crucial factor affecting shelf-life, fruit quality and consumer acceptance. Rabbiteye (RE; Vaccinium virgatum) blueberries are noted for their tough skin and lower pulp firmness compared to southern highbush (SHB; Vaccinium corymbosum L.). Yet limited firmness data is available on newly released RE genotypes bred for high yield, large berry size and increased firmness. The research objective was to evaluate weight loss, fruit firmness, and berry diameter on 14 RE and 3 SHB genotypes through storage. Blueberries were harvested from E.V. Smith Research station (Tallassee, AL) in 2024, then stored at 4 °C and 85% relative humidity. Four postharvest timepoints were followed: days 0, 14, 28, and 42 in storage. Firmness and fruit size were measured using a FruitFirm1000 texture analyzer, and weight loss was recorded using a digital scale. Significant changes in weight loss (%), firmness (g/mm), and fruit size (mm) during storage were found for the interaction between genotype and days in storage. On day 42, RE genotypes of ‘T-3081’, ‘Vernon’, and ‘T-3075’ exhibited the lowest weight loss at 7.2%, 7.8%, and 7.9%, respectively. Conversely, ‘MS1228R’ (18.3%), ‘MS1110R’ (13.6%), and ‘Titan’ (13.2%) (RE genotypes) and ‘Newhanover’ (14.9%) (SHB genotype) had the highest weight loss. During storage, most cultivars decreased in berry diameter. RE genotypes ‘Titan’, ‘T-3081’, and ‘T-3075’ had the largest diameter (24.9, 24.1, and 26.1 mm, respectively) at harvest and retained fruit diameter through storage (23.7, 23.4, and 26.1 mm, respectively). At harvest (day 0), ‘Titan’ (RE) had the highest firmness (287 g/mm), while ‘MS1110R’ (RE) had the lowest (152 g/mm). After 6 weeks of storage (day 42), RE genotypes of ‘Titan’, ‘Vernon’, ‘T-3075’, and SHB ‘Legacy’ maintained high firmness (˃200 g/mm), while ‘Alapaha’ (RE), ‘NewHanover’(SHB), and ‘MS1110R’ (RE) were lowest (˂150 g/mm). Hierarchical Cluster Analysis (HCA) identified three distinct firmness clusters, categorizing cultivars into enhanced (‘Titan’, ‘T-3075’), moderate (‘Legacy’, ‘Overtime’, and ‘T-3081’), and suppressed firmness (‘Alapaha’, ‘Krewer’, ‘Brightwell’, and ‘MS1110R’). HCA was crucial in selecting 10 genotypes (7 RE and 3 SHB) for future cell wall and texture analysis. This study provided valuable data for growers to select RE genotypes with maintained firmness and shelf-life. This data will aid blueberry breeders in selecting high-quality and competitive RE genotypes.

Speakers

Peter Ephraim

Graduate Research Assistant, Auburn University

Peter Ephraim is a PhD student in the Department of Horticulture at Auburn University. Peter has a strong background in food science, holding a bachelor’s degree in food science and technology from Lilongwe University of Agriculture and Natural Resources in Malawi and a Master’s... Read More →

Co-authors

Camila Rodrigues

Auburn University

Marlee Trandel Hayse

Auburn University

Michael Miller

Auburn University

Sushan Ru

Auburn University

Suzanne Johanningsmeier

United States Department of Agriculture-Agricultural Research Service (USDA-ARS)

Thursday July 31, 2025 1:00pm - 1:45pm CDT
Empire AB

Poster, Postharvest 2

Subject Postharvest
Funding Source Southern Region Small Fruit Consortium

1:00pm CDT

PH 2 - Comparison of Fruit Quality, Anthocyanin Contents, and Volatile Organic Compounds at Various Pigmentation Levels in Red

Thursday July 31, 2025 1:00pm - 1:45pm CDT

Empire AB

As consumer preferences and needs for strawberries have become increasingly diverse, various strawberry cultivars have been developed in Korea. Although the ‘Seolhyang’ (SH) cultivar still occupies the highest proportion in the strawberry industry, the proportion of strawberry cultivars has unique characteristics, including bigger size, higher ascorbic acid content, or unique color. One of the distinctive cultivars recently gaining attention is a white-pink colored strawberry known as ‘Cinderella’ (CD). Thus, the objective of this study aimed to evaluate the metabolic variations in secondary metabolites between SH and CD cultivars, based on the pigmentation of the fruit peel, which could be 0%, 50%, 75%, or 100%, following a 3-day cold storage period. The fully developed strawberry had a higher fresh weight and fruit diameter in CD than in SH cultivar. The peel color variables, including lightness, yellowness, and hue angle, were gradually decreased with fruit pigmentation. The redness of the peel increased rapidly along with fruit pigmentation in SH, while that of CD showed only a slight increase. The ethylene production rate indicated higher values in SH than in CD during fruit pigmentation. Fruit firmness gradually decreased while soluble solids content (SSC) increased along with fruit pigmentation, regardless of strawberry cultivars. The anthocyanin analysis revealed that the SH cultivar had notable levels of pelargonidin-3-O-glucoside, pelargonidin-3-(6”-malonylglucoside), and cyanidin-3-O-glucoside, which contributed to fruit pigmentation. In contrast, pelargonidin-3-O-glucoside was only detected in the CD cultivar. Based on the volatile organic compounds (VOCs) profiling, a total of 74 VOCs were detected, including 26 esters, 14 alcohols, 12 aldehydes, 9 ketones, 5 terpenes, and 3 acids. In SH cultivar, (E)-2-hexenal, (E)-nerolidol, methyl hexanoate, hexanoic acid, and linalool were major VOCs. On the other hand, methyl hexanoate, ethyl hexanoate, (E)-2-hexenal, mesifurane, and (E)-nerolidol were the main VOCs in the CD cultivar. Therefore, the results indicate that the profiles and levels of anthocyanins and VOCs were differently regulated during the pigmentation of strawberry fruit between SH and CD cultivars.

Speakers

Hyowon Park

Ph.D candidate, Chung-Ang University

Co-authors

Ho-Yeon Kim

Korea Institute of Science and Technology

Jinwook Lee

Chung-Ang University

Jiwon Park

Chung-Ang University

Joohyuk Jo

Chung-Ang University

Si-Eun Byeon

Chung-Ang University

Theintthandar Latt

Chung Ang University

PhD candidate at Postharvest Physiology Laboratory, Chung-Ang University.

Thursday July 31, 2025 1:00pm - 1:45pm CDT
Empire AB

Poster, Postharvest 2

Subject Postharvest
Funding Source This work was supported by the Korea Institute of Planning and Evaluation for Technology in Food, Agriculture and Forestry (IPET) through ‘Smart Agri Products Flow Storage Technology Development Program’ funded by Ministry of Agriculture, Food and Rural Affairs (MAFRA; Grant No. 322052052HD030).

1:00pm CDT

PH 2 - Degreening temperature can be lower for two seedless mandarin (Citrus reticulata Blanco) cultivars

Thursday July 31, 2025 1:00pm - 1:45pm CDT

Empire AB

Production of mandarin, sweet orange, and grapefruit has increased in most tropical and subtropical areas of the world in recent years due to growing market demand for high-quality, blemish-free fruit. Citrus fruit grown in the coastal region of the southeastern U.S. are more susceptible to blemishes and poor peel color than those grown in cooler climates. Early season, Florida mandarins are commonly degreened by treating with ≤ 5 ppm of ethylene for 12 h to 72 h at 29 °C /96% relative humidity (RH). However, optimal citrus degreening conditions vary with citrus cultivar, growing area, stage of maturity and season. Additionally, degreening can negatively affect mandarin quality (flavor, nutrition, acidity, sensory acceptability) and promote postharvest decays. The objective of this study was to evaluate the postharvest quality of two seedless mandarin cultivars degreened at temperatures lower than the commercial standard of 29 °C. These cultivars were released by the University of Florida breeding program: ‘UFGlow’, grown on ‘Rich’ trifoliate, ‘Carrizo’ citrange or ‘Sun Chu Sha’ mandarin rootstocks, and ‘UFSunrise’, grown on ‘Rich trifoliate’, ‘Carrizo citrange’ or HRS 812 rootstocks and were compared to the commercial cultivar ‘Owari-satsuma’, grown on ‘Carrizo citrange’ rootstock. On the day of harvest, fruit of each cultivar were pooled, treated with 5.0 μL·L-1 ethylene in a humidified, flow-through system for 72 hr at 20, 25 or 29 °C and 95% RH, then transferred to 8 °C/87% RH and evaluated weekly for 21 days. The three cultivars had better peel color and higher peel total carotenoid content when degreened at 25 or 29 °C than at 20 °C. Soluble solids content and total titratable acidity changed slightly during storage, independent of degreening treatment. Degreening did not affect ascorbic acid content; fruit total antioxidant capacity (oxygen radical absorbance capacity, ORAC) declined less with the ethylene treatment but remained constant in ‘UFGlow’. The best degreening treatment for these seedless mandarin cultivars was 5 ppm ethylene at 25 °C/96% RH for 72 hr, resulting in the best peel color, highest total peel carotenoids content, less weight loss and firmer fruit. Although ‘Owari’-satsuma developed better color at 29 °C, weight loss was significantly higher than when degreened at 20 or 25 °C.

Speakers

Steven Sargent

University of Florida

Professor and Extension Postharvest Specialist

Co-authors

Charles A. Sims

University of Florida/IFAS

Jose X. Chaparro

University of Florida/IFAS

Mark A. Ritenour

University of Florida/IFAS

Ramadhani O. Majubwa

Sokoine University of Agriculture

Theodosy Msogoya

Sokoine University of Agriculture

Thursday July 31, 2025 1:00pm - 1:45pm CDT
Empire AB

Poster, Postharvest 2

Subject Postharvest
Poster # csv

1:00pm CDT

PH 2 - Effectiveness of Blue Light Over Infrared for Sugar Estimation in Frozen Sweetcorn

Thursday July 31, 2025 1:00pm - 1:45pm CDT

Empire AB

We had earlier showed that spectrometric scanning of dehusked, fresh sweetcorn-on-the-cob (SOTC) in the visual (Vis) blue wavelength range (Vis-blue) offered an alternative nondestructive brix quantitation. In this report, we demonstrate that scanning in the Vis-blue is effective in a wide range of sample temperatures including freezing temperatures where the in-market infrared (IR) scanners fail. This is an important development for instore consumer decision-making experience. Eight packs of frozen (~-340C) SOTC in thin, translucent polyethylene packing bags were evaluated. Each pack contained at least12 pieces of SOTC, representing three different commercial brands bought directly from two different groceries stores on St. Croix. The samples were transported in ice and kept frozen (at temperature conditions as in the stores) until the time of measurements. At least six random SOTC were marked for IR and Vis-blue data every 5 minutes from freezing to room temperatures (~22degC) until the samples were completely thawed. The thawing temperatures at which each instrument was able to start recording were noted. The IR was insensitive at temperatures below ~160C, while the Vis-blue scanner recoded brix on frozen samples all the way to room temperatures and at complete sample thaw. The Vis-blue scanner also measured all frozen samples through the plastic packaging and directly on samples taken out of the packing. The Vis-blue scanner was also able to obtain spectral signals on the SOTC while the samples were in the freezer, but the signals were weak and, in some cases, when the sample packaging was completely covered in ice. With further developments and refinements, the Vis-blue scanning method can be integrated into scanning devices for quality assessments of frozen corn.

Speakers

Henry Awika

University of the Virgin Islands

Co-authors

Donna Gonzalez

University of the Virgin Islandss

Johnson Southwell

University of the Virgin Islandss

Thalia Stanley

University of the Virgin Islands

Thursday July 31, 2025 1:00pm - 1:45pm CDT
Empire AB

Poster, Postharvest 2

Subject Postharvest
Funding Source USDA-AMS-SCBR-VIDA

1:00pm CDT

PH 2 - Postharvest Assessment of Rabbiteye and Southern Highbush Blueberry Visual and Fruit Quality

Thursday July 31, 2025 1:00pm - 1:45pm CDT

Empire AB

Blueberries are valued for their flavor and nutritional content, yet postharvest data on rabbiteye (RE; V. virgatum A.) genotypes remain limited. In this study fruit quality of 16 RE and 3 southern highbush (SHB; V. corymbosum L.) genotypes were evaluated through cold storage. Fruit harvested in 2024 from E.V. Smith Research Center (Tallassee, AL) were stored at 4°C and 85% relative humidity in a randomized complete block design. Measurements were taken on days (d) 0, 14, 28, and 42 including color attributes (L*, a*, b*, C*, h* CIELAB units), soluble solids content (SSC, °Brix), titratable acidity (Tacid) and pH. Total anthocyanins (mg/g), phenolics (mg/100g), and DPPH antioxidant capacity (mM/100g) were quantitated via UV-VIS spectrophotometry. Significant interaction for days in storage*genotype were observed in Tacid and SSC:Tacid ratio. Tacid was highest in ‘MS1228R’ and ‘MS1234R’ (42d; 0.73 and 14d; 0.77) and lowest in ‘Legacy’ and ‘NC5303’ (42d; 0.30 and 0d; 0.31). The SSC:Tacid ratio was highest in ‘Brightwell’ (0d; 47.47) and lowest in ‘Vernon’ (0d; 19.76). SSC decreased with increased storage time (0d to 28d) by 0.69 °Brix while pH increased from 0d (3.31) to 42d (3.54). Genotype differences indicated ‘Brightwell’ and ‘Ochlocknee’ had the highest SSC (16.5 and 15.9 °Brix) compared to ‘T-3075’ and ‘New Hanover’ (12.4 and 12.1 °Brix). pH was highest in ‘Legacy’ and ‘New Hanover’ (3.67 and 3.63) and lowest in ‘T-3075’ and ‘MS1234R’ (3.25 and 3.19). Across all storage timepoints, RE genotypes were higher in total anthocyanins, phenolics and antioxidant activity at 16.54 mg/g, 298.40 mg/100g and 21.41 mM/100g, respectively compared to SHB genotypes at 11.35 mg/g, 213.90 mg/100g and 17.19 mM/100g. Hierarchical cluster analysis (HCA) indicated 3 clusters of interest. In cluster I, ‘Vernon’, ‘Overtime’ and ‘MS1595R’ had enhanced C* and h*. In cluster II, ‘Brightwell’ and ‘Ochlocknee’ indicated enhanced anthocyanin, phenolic and antioxidant activity, while ‘T-3075’ and ‘T-3072’ had suppressed phytonutrient content in cluster III. The industry accepted range for blueberry SSC is 11.2-14.3 °Brix and all genotypes in this study met industry standards. Some RE selections, e.g., MS selections, were above the U.S. accepted range (0.2 to 0.5) for Tacid relating to sour/tart flavors. HCA was useful in sub-selecting RE and SHB genotypes for sensory and electronic analysis to assess flavor patterns. Identifying fruit quality and flavor traits postharvest will aid in selecting superior RE germplasm to enhance consumer acceptance and inform breeding efforts.

Speakers

Clarisse Cochran-Chipura

Auburn University

Co-authors

Elina Coneva

Auburn University

Marlee Trandel Hayse

Auburn University

Sungeun Cho

Auburn University

Sushan Ru

Auburn University

Thursday July 31, 2025 1:00pm - 1:45pm CDT
Empire AB

Poster, Postharvest 2

Subject Postharvest
Funding Source AgR Seed Grant Program # 7008151

1:00pm CDT

PH 2 - The Effects of UV-Treated Hydroponic Nutrient Solution on Postharvest Quality of Romaine Lettuce

Thursday July 31, 2025 1:00pm - 1:45pm CDT

Empire AB

Romaine lettuce (Lactuca sativa L. var. longifolia) is a highly nutritious, leafy green vegetable that can be easily grown hydroponically, offering a sustainable and efficient alternative to conventional agricultural practices. Although hydroponically grown lettuce is less susceptible to microbial infection compared to its soil-grown counterparts, contamination with human pathogens is still possible. Sterilization methods, such as ultraviolet (UV) light treatment, may be employed to control contamination in the hydroponic system, but its effect on lettuce postharvest quality remain unclear. The aim of this study was to investigate the impact of nutrient solutions treated with two doses of UV-C on the harvest and storage quality of the romaine lettuce cultivar 'Sparx' grown in a deep-water culture (DWC) hydroponic system. Nutrient solutions were either left untreated (control) or treated three times over a six-week growing period with UV-C (254 nm) at two different flow rates, delivering estimated UV-C doses of 18.93 mJ/cm² (low) or 37.85 mJ/cm² (high) per treatment. Postharvest quality was evaluated by measuring leaf length, fresh weight, dry root weight, water loss, soil plant analysis development (SPAD), color, texture, visual quality, respiration rate, micronutrient content, and nutritional content at time of harvest and over a seven-day storage period. We utilized a randomized complete block design, and the experiment was repeated three times. Lettuce grown in the low dose UV-C-treated nutrient solution had significantly longer lettuce leaf length, higher fresh weight, and higher vitamin C content compared to the high dose UV-C treatment. Additionally, fresh shoot weight was significantly higher in the low dose UV-C-treated lettuce compared to the high dose treatment. In terms of visual quality, the high dose UV-C treatment showed significantly better visual quality at the end of storage compared to lettuce grown in the control nutrient solution. No significant differences were observed for dry root weight, water loss, SPAD, texture, color, or micronutrient content between the three treatment groups. Overall, this study demonstrates that UV-C-treated nutrient solution had no negative impact on quality parameters of hydroponic lettuce at harvest or during storage, indicating that UV-C treatment, particularly at lower doses, may be a viable option for effectively sterilizing hydroponic systems without compromising lettuce postharvest quality.

Speakers

Tori Kent

Kansas State University

Co-authors

Eleni Pliakoni

Kansas State University

Manreet Bhullar

Kansas State University

Sachin Adhikari

Kansas State University

Tricia Jenkins

Kansas State University

Thursday July 31, 2025 1:00pm - 1:45pm CDT
Empire AB

Poster, Postharvest 2

Subject Postharvest
Funding Source Kansas State University Global Food Systems Seed Grant Program

1:44pm CDT

PH 3 - Oral Session

Thursday July 31, 2025 1:44pm - 1:45pm CDT

Strand 11B

Presiding/Moderator

Deepak Kumar Jha

Texas A

Thursday July 31, 2025 1:44pm - 1:45pm CDT
Strand 11B

Oral presentation, Postharvest 3

Subject Postharvest

1:45pm CDT

PH 3 - Priming onion seeds with iron and copper nanoparticles enhances yield, reduces pungency, and improves postharvest qualit

Thursday July 31, 2025 1:45pm - 2:00pm CDT

Strand 11B

Priming seeds with nanoparticles (NPs) has the potential to enhance germination, growth, and resilience against environmental stresses by inducing the biosynthesis of secondary metabolites, which promote plant protection and health. However, the effectiveness of the essential micronutrients iron (Fe) and copper (Cu) as priming agents for crop production and postharvest qualities is largely unexplored. This study examines the impact of seed priming with Fe- and Cu-NPs on the production of onions, a crop of significant economic importance in Texas. NPs were synthesized using a green approach that employs onion juice as a reducing agent. The resulting Fe-NPs and Cu-NPs were characterized, and an optimal dose, determined by the length of root and shoot growth, was employed as a priming agent for two commercial yellow onion varieties (Legends and Pecos) and two Texas A

Speakers

Deepak Kumar Jha

Texas A

Co-authors

Bhimanagouda S. Patil

Texas A

John Jifon

Texas A

Subas Malla

Texas A

Vikas Dadwal

Texas A

Thursday July 31, 2025 1:45pm - 2:00pm CDT
Strand 11B

Oral presentation, Postharvest 3

Subject Postharvest

2:00pm CDT

PH 3 - Storage of ‘Covington’ Sweet Potatoes Under Controlled Atmosphere Conditions: Effects on Quality and Shelf Life

Thursday July 31, 2025 2:00pm - 2:15pm CDT

Strand 11B

Sweet potato is a nutritious root crop, rich in fibers, beta-carotene and vitamin C, especially in highly pigmented varieties. The warm climate of Georgia provides ideal conditions for the cultivation of sweet potatoes. Maintaining postharvest quality during long-term storage remains a challenge for sweet potatoes packers and shippers. This study aimed to evaluate the effects of controlled atmosphere (CA) storage on the postharvest quality and shelf life of ‘Covington’ sweet potatoes. Roots from two farms in South Georgia, Herring Farms (HF) and Bland Farms (BF), were cured at 29 °C and 85–90% relative humidity (RH), for three weeks and one week, respectively. After curing, samples were stored at 13 °C and 85–90% RH for up to six months under different atmosphere compositions: (1) Air 21 kPa O2-Control, (2) 7 kPa O2, (3) 7 kPa O2 2 kPa CO2, and (4) 7 kPa O2 10 kPa CO2, using an Oxystat 200 control atmosphere system, which mixed and regulated O2 and CO2 gases under constant pressure, ensuring gas levels within ± 0.5% of the target concentrations. After cold storage, roots were transferred to ambient conditions (21 °C and 85–90% RH) to simulate market and consumer handling. Quality parameters, including firmness, color, weight loss, decay incidence, sprouting, and respiration rates, were assessed at six time points: one month, one month plus two weeks at ambient conditions (AC), three months, three months plus two weeks at AC, six months, and six months plus two weeks at AC. For each location, 1,260 roots were evaluated, with 315 roots assigned to each atmospheric composition (three replicates of 15 roots per evaluation time point). Results demonstrated that storage under low O2 and moderate CO2 levels (7 kPa O2 2 kPa CO2) reduced weight loss and decay while maintaining higher firmness compared to Control (storage in air). In contrast, higher CO2 levels (10 kPa) resulted in increased weight loss and surface decay. These findings suggest that controlled atmosphere storage with low O2 and moderate CO2 levels can improve postharvest quality and extend the shelf life of sweet potatoes, whereas higher CO2 levels negatively affect postharvest quality of Georgia-grown ‘Covington’ sweet potatoes.

Speakers

Jakeline Zuluaga Acosta

University of Georgia

Co-authors

Angelos Deltsidis

University of Georgia

Wei-Shiang Liao

University of Georgia

Thursday July 31, 2025 2:00pm - 2:15pm CDT
Strand 11B

Oral presentation, Postharvest 3

Subject Postharvest

2:15pm CDT

PH 3 - Zinc Nanoparticles as a Seed Priming Agent to Improve Postharvest Quality of Onion Bulbs

Thursday July 31, 2025 2:15pm - 2:30pm CDT

Strand 11B

Sweet onions (Allium cepa L.) are becoming increasingly popular due to their mild, sweet flavor and low pungency. Consequently, enhancing their pre- and post-harvest quality attributes has emerged as a key area of research. One promising method is seed nanopriming, where seeds are pre-treated with nanoparticles (NPs) to improve germination, overall plant growth, and quality. Zinc (Zn) plays a crucial role in plant metabolism, acting as a cofactor for various enzymes involved in processes like auxin production and chlorophyll synthesis, and onions are particularly sensitive to Zn deficiency. This study investigated seed nanopriming in four onion varieties: two yellow commercial types (Legend Onion and Pecos Onion) and two Texas A

Speakers

Jelisha Perera

Texas A

Thursday July 31, 2025 2:15pm - 2:30pm CDT
Strand 11B

Oral presentation, Postharvest 3

Subject Postharvest

2:30pm CDT

PH 3 - Strawberries - A Plea for Common Sense for Research on Edible Coatings

Thursday July 31, 2025 2:30pm - 2:45pm CDT

Strand 11B

A large and expanding literature about the application of skin coatings to fruits and vegetables has developed. Interest in coatings is being driven in part by concerns about the use of plastic films for packaging. While several major crops are routinely treated with coatings, many research studies do not consider the commercial logistics of applying coatings to the product. The prime example of this issue is strawberry fruit, which are usually field packed into clam shell containers, cooled, and in some cases stored in pallet shrouds that are injected with high carbon dioxide, before being sent to market. Despite claims that strawberry storage is problematic because of its short storage life, the market size continues to grow steadily, e.g., internationally from $15.3 billion in 2023 to $15.88 billion in 2024, success being based on cultivar selection and standard technologies. Despite this, numerous reviews on postharvest handling of strawberries cite technologies and treatments as if they are applied commercially. A Web of Science search with the words ‘strawberry’ and ‘skin coatings’ reveals 760 publications, mostly in the last 25 years. The reality is that almost without exception, no commercial application is viable because they do not fit well with harvest and handling processes that are focused on getting fruit market expeditiously. Breeding programs are critically important strategies to improve strawberry fruit storability. Where postharvest technologies or treatments may have a place for further development it most likely through modified atmosphere packaging either passive or active. The best coating for strawberries is chocolate.

Speakers

Chris Watkins

Cornell University

Thursday July 31, 2025 2:30pm - 2:45pm CDT
Strand 11B

Oral presentation, Postharvest 3

Subject Postharvest
Funding Source Hatch multistate NE2336

10:14am CDT

PH 4 - Oral Session

Friday August 1, 2025 10:14am - 10:15am CDT

Foster 1

Presiding/Moderator

Sushan Ru

Auburn University

Friday August 1, 2025 10:14am - 10:15am CDT
Foster 1

Oral presentation, Postharvest 4

Subject Postharvest

10:15am CDT

PH 4 - Sensory and Quality Assessment of Rabbiteye and Southern Highbush Blueberry Genotypes

Friday August 1, 2025 10:15am - 10:30am CDT

Foster 1

Rabbiteye blueberries (RE; V. virgatum A.) are perceived to have poor fruit quality compared to southern highbush (SHB; V. corymbosum L). Comprehensive quality assessments of RE genotypes during storage are scarce. To understand fruit quality differences firmness, general composition and phytonutrient contents in 5 RE (‘Brightwell’, ‘Vernon’, ‘MS1110R’, ‘T-3072’ and ‘T-3075’) and 1 SHB (‘Legacy’) genotype were evaluated. Fruit harvested from E.V. Smith Research Center (Tallassee, AL) were stored at 4°C at 85% relative humidity. Measurements were taken on days 0 and 14 (0d and 14d) in storage. Firmness was measured using a FruitFirm1000 (g/mm). Soluble solids content (SSC, °Brix), titratable acidity (Tacid) and pH were assayed. Total anthocyanins (mg/g), phenolics (mg/100g), and DPPH antioxidant capacity (mM/100g) were quantitated via UV-VIS spectrophotometry. Days in storage*genotype were significant in firmness, Tacid, pH, anthocyanins, phenolics, and antioxidants. ‘T-3072’ had the highest firmness (0d; 289.97 g/mm) compared to ‘MS1110R’ (0d; 130.61 g/mm). ‘Vernon’ (0d; 0.66) had the highest Tacid while ‘Legacy’ (0d; 0.34) was lowest. Conversely, pH was highest in ‘Legacy’ (0d; 3.68) and lowest in ‘T-3075’ (0d; 3.12). Anthocyanins and antioxidants were highest in ‘MS1110R’ on 0d (28.62 mg/g and 29.59 mM/100g) and phenolics were highest in ‘Brightwell’ after 2 weeks of storage (426.97 mg/100g). Genotype differences indicated SSC was highest in ‘Brightwell’ (16.19) compared to ‘Legacy’ (12.03). Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were performed on 0d and 14d among the genotypes to better determine how composition changed during storage. PCA indicated ‘Legacy’ clearly separated from the RE genotypes and was negatively correlated to firmness and all composition and nutritional traits. HCA determined three clusters of interest with similar genotype characteristics from 0d to 14d. In cluster I, ‘T-3072’ and ‘T-3075’ maintained moderate to enhanced firmness. ‘Legacy’ had consistently suppressed SSC and Tacid (Cluster II). While ‘Brightwell’ and ‘MS1110R’ had enhanced anthocyanins, phenolics and antioxidants (Cluster III). Reduced SSC and Tacid are associated with lower perceived sweetness and sourness. RE genotypes demonstrated higher SSC and enhanced nutritional content, making them appealing for health-conscious consumers. Sensory analysis on 4 RE and 2 SHB genotypes will be conducted utilizing a trained panel to determine differences in sweetness, sourness, texture and aroma. We expect analyzing sensory data with physicochemical assays will further provide insightful information helpful in developing acceptable RE genotypes with preferred flavor and texture.

Speakers

Sushan Ru

Auburn University

Co-authors

Clarisse Cochran-Chipura

Auburn University

Elina Coneva

Auburn University

Marlee Trandel Hayse

Auburn University

Sungeun Cho

Auburn University

Friday August 1, 2025 10:15am - 10:30am CDT
Foster 1

Oral presentation, Postharvest 4

Subject Postharvest

10:15am CDT

Workshop: Strengthening Latin American Horticultural Products in the U.S.: Fruits, Vegetables, and Ornamentals

Friday August 1, 2025 10:15am - 12:15pm CDT

Strand 10

WORKSHOP OBJECTIVES
The primary goal of this workshop is to bring together a diverse network of professionals from academia, industry, extension services, and government agencies who are working to enhance the performance, sustainability, and resilience of Latin American horticultural supply chains to the U.S.
Participants will:

Share knowledge on how to improve quality, minimize postharvest losses, and meet regulatory and market demands.
Highlight opportunities for supporting Latin American growers, exporters, and logistics providers.
Explore cross-cutting themes including climate resilience, labor, sustainability, and technology adoption.
Foster collaboration and lay the groundwork for future events focused on Latin America and horticulture.

Speakers:

Jorge Vanegas – jvenegas@pairwise.com
Juan Rodriguez – jc@foginfo.org

WORKSHOP FORMAT
I. Expert Presentations (35 minutes total)
Three panelists (15 minutes each) will present on the following themes:

Production and Sustainability: Emerging challenges and innovations in Latin American fruit, vegetable, and ornamental production systems.
Postharvest and Quality Management: Best practices to preserve quality and extend shelf life during export, focusing on compliance with U.S. standards.
Trade and Market Access: Navigating U.S. regulations, phytosanitary requirements, and certification systems, with insights into logistics and cold chain management.

II. Experience Sharing from the Field (15 minutes)
A moderated session where 5–6 attendees will briefly (2–3 minutes each) share their field experiences working in or with Latin American horticultural systems. This segment will offer valuable context and grassroots perspectives to enrich the subsequent discussions.
III. Breakout Group Discussions (25 minutes)
Participants will join focused roundtables based on key crops or sectors (e.g., tropical fruits, temperate fruits, vegetables, ornamentals). Each group will explore:

Specific supply chain challenges
Opportunities for innovation and collaboration
Regional production and trade differences

IV. Group Reporting & Strategy Sharing (15 minutes)
Groups will reconvene to summarize key insights and report out barriers and proposed solutions (e.g., cold chain infrastructure gaps, pest and disease pressures, labor constraints, traceability needs). A shared whiteboard will capture these points to inform follow-up actions.

V. Building Toward Future Collaboration (15 minutes)
The workshop will conclude with an open discussion to identify opportunities for future collaboration. This may include organizing a follow-up workshop or proposing a broader symposium or conference focused on Latin American Horticulture—bringing together academic, industry, and government stakeholders to build long-term partnerships and shared research agendas.

Friday August 1, 2025 10:15am - 12:15pm CDT
Strand 10

Interactive Workshop

Subject Latin America, Postharvest, Sustainability

10:30am CDT

PH 4 - Climate and weather's effects on sweet cherry quality and maturity in extended storage

Friday August 1, 2025 10:30am - 10:45am CDT

Foster 1

Climate variability causes unpredictable seasonal weather events during the fruit-growing period. This affects fruit set and quality by affecting ripening and deterioration rates postharvest. The goal of this research was to study how different weather conditions affected fruit quality at harvest and their storage potential. Four sweet cherry cultivars (Rainier, Bing, Skeena, Sweetheart) grown commercially in Central WA during 2021-2024 were harvested at two different times and stored in air (0-1 oC) for 30 days. Maturity indices (weight, color, firmness, soluble solids), stem condition, and defects were evaluated every two weeks plus 2 days at 5-6 oC simulating refrigerated shelf-life. Overall, the seasonal weather had a significant impact on fruit quality at harvest and postharvest. Fruit firmness varied among seasons in all cultivars and increased over time in storage in most cases. Skin color was only affected by harvest time. No clear trends across cultivars were observed with soluble solids content or fruit weight. The stem condition declined with time postharvest, but the rate was season- and cultivar-dependent. Positive correlations between bioclimatic indexes and the rate of deterioration (including pitting and pebbling) were found that need further investigation.

Speakers

Carolina Torres

Washington State University

Co-authors

Gabriela Bolanos-Pabon

Washington State University

Rene Mogollon

Washington State University

Friday August 1, 2025 10:30am - 10:45am CDT
Foster 1

Oral presentation, Postharvest 4

Subject Postharvest
Funding Source USDA-AFRI

10:45am CDT

PH 4 - Continuous High-Pressure Homogenization for Reducing Thermal Degradation and Preserving Bioactive Compounds in Fruit Juices

Friday August 1, 2025 10:45am - 11:00am CDT

Foster 1

The preservation of bioactive compounds in fruit juices is essential for maintaining their nutritional value and consumer appeal. This study explores the potential of Continuous Flow High-Pressure Homogenization (CFHPH) as a promising alternative to traditional thermal processing methods, such as High-Temperature Short-Time (HTST), in fruit juice production. CFHPH has demonstrated effectiveness in preserving bioactive compounds, including ascorbic acid, carotenoids, anthocyanins, and phenolic acids, while significantly reducing the thermal degradation of heat-sensitive compounds associated with HTST. In this research, we compared CFHPH to HTST in juices from horticultural crops, including watermelon, blueberry, and grapefruit. CFHPH treatment at 300 MPa and an inlet temperature of 4 °C maintained higher levels of carotenoids, anthocyanins, and ascorbic acid during storage, while also reducing the activity of oxidative enzymes such as polyphenol oxidase (PPO) and peroxidase (POD) across all tested fruits. In contrast, HTST processing resulted in a considerable loss of bioactive compounds due to oxidation and thermal degradation. CFHPH not only preserved essential nutrients but also extended shelf life under market-simulated storage conditions by minimizing oxidative damage and reducing particulate sedimentation, making it an ideal solution for the growing demand for minimally processed, nutrient-rich fruit juices. This technology offers significant potential for the horticulture and food industries, ensuring fresh, nutritious, and appealing juices for health-conscious consumers.

Speakers

Jayashan Adhikari

Texas A

Co-authors

Bhimanagouda Patil

Texas A

Koushik Adhikari

University of Georgia

Rakesh Singh

University of Georgia

Friday August 1, 2025 10:45am - 11:00am CDT
Foster 1

Oral presentation, Postharvest 4

Subject Postharvest

11:00am CDT

PH 4 - Texture Profiling of 7 Rabbiteye and 3 Southern Highbush Blueberry Genotypes During Postharvest Cold Storage

Friday August 1, 2025 11:00am - 11:15am CDT

Foster 1

Blueberry (Vaccinium spp.) texture is a key trait in breeding programs primarily due to its influence on consumer acceptance, machine harvestability, transportability, shelf-life, and overall quality. Variations in firmness have been extensively studied on southern highbush (SHB; Vaccinium corymbosum L.), with little reported on rabbiteye (RE; Vaccinium virgatum) genotypes. Various texture instruments, including FruitFirm1000, FirmTech II, and TA.XT2 Plus texture analyzers, are used, but not all assess multiple mechanical parameters on blueberry fruit. Initial firmness evaluations on 17 RE and SHB genotypes using a FruitFirm1000 identified genotype-specific variations over six weeks of storage (4 °C, 85% relative humidity). At harvest (day 0), ‘Titan’ (RE) had the highest firmness (287 g.mm-1), while ‘MS1110R’ (RE) had the lowest (152 g.mm-1). After 4 weeks in storage (day 28), RE genotypes of ‘Titan’, ‘Vernon’, ‘T-3075’, and SHB ‘Legacy’ maintained high firmness (˃200 g.mm-1). While ‘Alapaha’ (RE), ‘New Hanover’(SHB), and ‘MS1110R’ (RE) did not retain firmness (˂150 g.mm-1). Texture is a complex and multi-component trait; a single firmness measurement cannot comprehensively capture all attributes influencing blueberry texture variations. To further understand blueberry mechanical parameters, our current study utilizes a TA.XT2Plus texture analyzer equipped with 2 mm needle and 2 mm flat probe. The needle probe will measure force parameters across different blueberry tissues: epidermis (Fep), hypoderm (Fh), parenchyma (Fp), and inner pulp (Finner). The 2 mm flat probe will measure mechanical parameters derived from force-distance curves, which relates to skin elasticity, internal firmness, graininess/grittiness, skin strength, and stiffness (Young’s modulus). Ten blueberry genotypes (7 RE and 3 SHB) representing distinct crisp/high, medium, and low firmness levels will be harvested and stored at 4 °C and 85% relative humidity. Texture measurements will be taken at two postharvest timepoints, day 0 and 14. By integrating advanced texture analysis (TA.XT2Plus) compared to FruitFirm1000, a comprehensive understanding of firmness variability and texture changes in RE compared to SHB blueberries will be obtained. The advanced textural assessment will enable data-driven insights to inform breeding selections for improved texture in fresh-market cultivars.

Speakers

Peter Ephraim

Graduate Research Assistant, Auburn University

Co-authors

Camila Rodrigues

Auburn University

Marlee Trandel Hayse

Auburn University

Michael Miller

Auburn University

Sushan Ru

Auburn University

Suzanne Johanningsmeier

United States Department of Agriculture-Agricultural Research Service (USDA-ARS)

Friday August 1, 2025 11:00am - 11:15am CDT
Foster 1

Oral presentation, Postharvest 4

Subject Postharvest

11:15am CDT

PH 4 - Hyperspectral Imaging for Haskap Berry Firmness Prediction: A Non-Destructive Approach.

Friday August 1, 2025 11:15am - 11:30am CDT

Foster 1

Firmness is an important quality attribute for assessing fruit maturity, postharvest management, and consumer acceptance. Texture profile analyser and penetrometers are two destructive and time-consuming traditional methods for measuring firmness. Hyperspectral imaging presents a potential non-destructive alternative by acquiring the spectral and spatial data of fruits. The ability of hyperspectral imaging to predict firmness of Haskap berries (Lonicera caerulea) at various ripening stages is investigated in this study. Hyperspectral images of the Aurora cultivar were collected at 3 harvesting stages (early, mid, late), 3 growing positions (high, middle, low), and different sunlight exposure conditions (partial shade, full sun). The spectral data was collected for a selected region of interest. The reflectance spectra (396.92-1033.95 nm) were analysed, and different models were developed using neural network (R2= 0.44; RMSE= 0.35), general regression (R2= 0.41; RMSE= 0.36), partial least squares (R2= 0.45; RMSE= 0.35) and bootstrap (R2= 0.63; RMSE= 0.28) predictive modelling methods. The preliminary results of the research study findings imply that hyperspectral imaging is a viable tool for promptly estimating firmness and classifying the ripeness stage of haskap berries. By integrating hyperspectral imaging and data-driven approaches, growers can significantly enhance fruit quality and optimize decision-making processes, enabling better pre- and postharvest management.

Speakers

Mohit Sharma

Université Laval

Co-authors

Arturo Duarte Sierra

Université Laval

Rani Puthukulangara Ramachandran

Agriculture and Agri-Food Canada

Friday August 1, 2025 11:15am - 11:30am CDT
Foster 1

Oral presentation, Postharvest 4

Subject Postharvest
Poster # csv

11:30am CDT

PH 4 - Non-destructive assessment of sunscald at harvest improves storage outcome for Granny Smith apples

Friday August 1, 2025 11:30am - 11:45am CDT

Foster 1

Although sunlight is crucial for optimal apple production, excessive sun exposure can negatively impact appearance and alter internal quality of the fruit. Sun stress-related disorders are the primary cause of economic losses in major apple-growing regions. Granny Smith, the third most produced variety in Washington State, is notably prone to sunscald, a postharvest disorder manifested by the superficial darkening of the peel, rendering the fruit unmarketable. Lower chlorophyll and higher carotenoid concentration in Granny Smith peel is associated with increased sunlight exposure and a higher likelihood of sunscald development. In this research, the chlorophyll-to-carotenoid ratio measured non-destructively with a hyperspectral imager at harvest was used to categorize apples according to sunscald susceptibility: high, moderate, low, and very low. The quality parameters for apples in each sunscald risk category were evaluated to determine whether pre-storage sorting based on sun exposure could enhance the consistency of cold chain quality and performance. It was hypothesized that relative sun exposure has a significant influence on apple quality parameters and ripening patterns during storage. Apples were harvested from three orchards over three consecutive years and subsequently stored in air for six months before quality analyses. During the final year, additional assessments were conducted at four and five months of storage to monitor the progression of ripening and sunscald incidence. A multi-year analysis including firmness, soluble solids, titratable acidity, greenness (Iad), peel lightness (L*), and the chromatic shift from green to yellow (a/b) resulted in similar classifications among categories. However, changes in internal quality parameters attributable to relative sun exposure were evident when analyzing fruit from a single location and season. Overall, apples classified as having high and moderate sunscald risk exhibited elevated soluble solids and reduced titratable acidity compared to those in lower sunscald risk categories. Additionally, these quality parameters were more variable for fruit with high and moderate sunscald risk. The ripening pattern was similar for fruit in the low and very low categories, with a more homogeneous data distribution. The incidence of sunscald increased over time and with increased sun exposure, resulting in 11% fruit loss after 6 months of storage. Although the primary benefit of the sunscald susceptibility index is to enhance commercial viability by enabling apples in high-risk categories to be sold before sunscald symptoms render them unmarketable, sorting and grouping fruit based on relative sun exposure rendering a more homogenous storage outcome, potentially reducing economic losses for growers and packers.

Speakers

Oral presentation, Postharvest 4

Subject Postharvest
Funding Source This work was supported by the USDA-NIFA-OREI (grant 2021-51300-34914); The USDA-ARS Penn State Cooperative Agreement: 58‐6034‐3‐016 and by the Grant PRE2021-100809 funded by MICIU/AEI/10.13039/501100011033 and by European Social Fund Plus (ESF+). F. Di Gioia’s contribution was supported by the USDA National Institute of Food and Agriculture and Hatch Appropriations under Project no. PEN04723 and Accession no. 1020664.
Funding Option OREl or ORG funded all or part of the research associated with this abstract