局部发热过程中进口大豆品质劣变规律研究

进口大豆在海上运输及储藏的过程中，容易因环境温湿度变化使得大豆局部含水量升高，从而引起局部发热，导致品质劣变。本文采用120 kg含水量16%和含杂量50%大豆局部包埋的方式，室温下常规储藏，模拟探究其局部发热条件及品质变化。结果表明：水分含量高的大豆更容易发热，对品质变化影响较大，包埋水分含量为20%的大豆在储藏21 d后，粗脂肪含量下降了0.95个百分点，酸价上升了4.36 mg?g^-1，总不饱和脂肪酸含量下降了0.92%，蛋白持水性下降了1.09 g·g^-1，持油性上升了0.78 g·g^-1，乳化活性指数和乳化稳定性分别增加了3.38 m²·g^-1和2.59%。而包埋120 kg含水量16%的大豆和包埋120 kg含杂量50%的大豆发热慢，发热温度较低，大豆粗脂肪、蛋白品质指标变化趋势相似，但是变化幅度较小。

Quality deterioration of imported soybean during local heating process

During the maritime transportation and storage of imported soybeans, the changes of environmental temperature and humidity lead to the increase of local moisture content, resulting in local heating, and eventually lead to quality deterioration of soybean. In this paper, 120 kg soybean with different water content and impurity content was embedd in simulated warehouse to simulate local condition, the soybean quality was investigated during storage process at room temperature. The results showed that, the higher the moisture content of embedded soybean, the more easily the soybean quality was affected. After 21 days of storage, the crude fat content of the soybean with moisture content of 20% decreased by 0.95%, the acid value increased by 4.36 mg·g^-1, and the total unsaturated fatty acid content decreased by 0.92%, protein water holding capacity decreased by 1.09 g·g^-1, oil holding capacity increased by 0.78 g·g^-1, emulsification activity index and emulsification stability increased by 3.38 m²·g^-1 and 2.59%, respectively. However, the soybean embedded with water content of 16% or with impurity content of 50% have slower heating and lower heating temperature. The change trend of soybean crude fat and protein isolate quality index was similar, but the change range was smaller.