Effects of Storage Temperature and its Fluctuation on Keeping Quality of Mungbean Sprouts

Studies on Production and Keeping Quality of Bean Sprouts

Abstract

The deterioration of quality of mungbean sprouts during storage was caused by wilting of hypocotyl, followed by abscission of cotyledon, softening of tissue, development of stick and russet, and then decay. The optimum temperature for the storage of mungbean sprouts was 0°C. At 5°C, mungbean sprouts were kept in good condition almost similar to that at 0°C, except slightly faster change in color of hypocotyl than that at 0°C. The limiting period of marketability of mungbean spropts was 13-15 days at 0°C and 5°C, 5-6 days at 10°C, and 2-3 days at 20°C. The lowering rate of freshness of mungbean sprouts was accelerated by the increase of fluctuating storage temperature or by the increase of the storage time. It was also found that when the temperature was fluctuated 20°C to 0°C, the lowering rate of freshness was accelerated more than that at steady temperature of 20°C. The holding period of freshness was shortened by 4-5 days, even when mungbean sprouts were kept for only 1-2 hours at 20°C, compared with 7 to 10 days of steady 0°C-samples. Hardness value of hypocotyl at the time when the deterioration of freshness began was about 400dyn/g and it was about 350dyn/g when considerably deteriorated. A marked deterioration of Inungbean sprouts was observed by 55 of Hunter polar angular b value for hypocotyl, though the value for hypocotyl of fresh mungbean spropts was 50.