Changes in Postharvest Respiration, Growth, and Vitamin C Content of Soybean Sprouts under Different Storage Temperature Conditions

摘要

To understand the postharvest characteristics of soybean sprouts, 5-day-old sprouts were harvested, packed in PE film, and stored at 4,12, and 20 °C for up to 4 days. In addition, the sprout respiration rate was measured after storage at 4, 8,12,16,20, and 24 °C for up to 20 h. During the first day of storage at 20 °C, the sprouts maintained temperature-dependent longitudinal growth, especially of hypocotyl length; hypocotyl and root grew 0.8 cm and 0.2 cm, respectively. The hypocotyl thickness decreased by 11,13, and 18 % after 4 days of storage at 4, 12, and 20 °C, respectively. No temperature-dependent differences in fresh weight, dry weight, or water content were found, despite decreases of 3 % over the 4 days of storage. A significant postharvest decrease of 50 % in vitamin C content was observed in the sprouts stored at 20 °C for 3 days. Based on the CO_2 production rate, the soybean sprouts exhibited an increase in respiration in proportion to the storage temperature; sprouts stored at8,12,16,20, and 24 °C showed approximately 2, 5, 6,11, and 17 times, respectively, than the respiration rate of sprouts stored at 4 °C. These results indicate the importance of low temperature storage during market circulation for minimizing the postharvest morphological and nutritional degradation of soybean sprouts.