The rancidity of soybean (Glycine max L.) from Yeonhaeju, called “Bazaz”, in powder forms was evaluated through a fluorescence spectrum test (FST). The results from the FST were validated by comparing the TBA and acid values. Soybean powders were stored in 25, and 90℃ for 20 days. The maximum excitation and maximum emission of fluorescent compounds generated from the soybean powder during storage were observed at the 360 nm and 430-440 nm wavelengths, respectively. The mean particle size of soybean powder was maintained at 40 μm to avoid the dependence of the reaction area during measurement. According to the FST results, lipid oxidation did not actively progress during storage at 25℃. The fluorescence intensity (FI) from FST on the first day of storage was not significantly different from that on the last day of storage (day 20; p < 0.05), but the FI dramatically increased at 90℃. A smooth increase was observed in the initial stage; then, after 11 days of storage, the FI value increased by nearly 100% compared to that on the first day. The FI values were compared with TBA and acid values that were measured under the same storage conditions. All the values at 25℃ showed similar patterns during storage, but at 90℃, the FI and acid values showed similar patterns but the TBA decreased after reaching the maximum values on storage day 12. The results demonstrated that FST may be useful for measuring the rancidity of the powder form of soybean because it does not require extraction to measure the rancidity.

• 엄주태(강원대학교 바이오산업공학부 식품생명공학전공) | Joo-Tae Uhm
• 윤원병(강원대학교 바이오산업공학부 식품생명공학전공, 강원대학교 생명공학연구소, 강원대학교 농업생명과학연구원) | Won-ByongYoon Corresponding author