Influence of storage on the characteristics of soybean, soymilk and tofu

Abstract

Soybeans are subject to storage and shipping after harvest. During this period of time, the physical and biochemical characteristics of soybean may change to various degrees, depending upon the initial soybean moisture and storage/shipping conditions, including various humidities and temperatures. The changes in soybean characteristics may include darkening in surface color, increase in hydration time, reduction in solid and protein solubility, decrease in phytate content, isoflavone structural conversions, changes in protein structures, sugar pattern and lipid oxidation. The coagulant requirement per unit weight of soymilk for tofu making is reduced by improper storage. The yield and quality of soymilk and tofu are also negatively affected by severe storage conditions. Proper storage/shipping management is necessary to keep soybean quality for making high quality soy foods. Therefore, storage research is important to provide useful information for the soybean industry to better manage soybeans during harvest, storage, and transportation to maintain good quality for tofu making.