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.
