大豆中苷元型异黄酮可直接被人体消化吸收，而其他异黄酮必须要经过水解去除糖基后才能被吸收利用。本研究通过模拟工业生产中常用的巴氏杀菌（95 ℃）、高温短时杀菌（121 ℃）和超高温瞬时杀菌（143 ℃），阐述了豆浆加热过程中异黄酮单体之间的转化，并对主要异黄酮的热降解进行了动力学分析，以期为生产高比例苷元型异黄酮的豆浆提供理论依据。生豆浆中丙二酰型异黄酮含量最高，其次分别为糖苷型和苷元型。3种热处理均导致丙二酰型异黄酮含量降低，符合一级降解动力学，且温度越高，降解速率常数越大。95 ℃处理主要导致丙二酰型向糖苷型转化，而143 ℃时异黄酮主要发生降解而非转化。121 ℃处理后，豆浆中苷元型异黄酮含量显著增加，比生豆浆提高50%，显著提高了豆浆品质。相对其他两个热处理温度，高温短时杀菌能减少异黄酮分解提高苷元型含量，更适合于豆浆工业化生产。

Soy aglycone isoflavones can be assimilated directly by humans, whereas isoflavones in other forms can only be absorbed after the removal of the sugar moiety via hydrolysis. In this paper, the conversion of individual isoflavones during the heating of soymilk was illustrated by stimulating pasteurization (95 ℃), high-temperature short-time sterilization (121 ℃), and ultra-high temperature instantaneous sterilization (143 ℃), processes that are commonly used in industry. In addition, the kinetic analysis of the thermal degradation of major isoflavones was also conducted, in order to provide a theoretical basis for the production of a high proportion of aglycone isoflavones in soymilk. In raw soymilk, the content of malonylglucoside isoflavones was the highest, followed by glycoside and aglycone isoflavones. All three heat treatments resulted in the decrease of malonylglucoside isoflavones, which followed first-order reaction kinetics. In addition, the degradation rate constants increased with increasing temperature. The heat treatment at 95 ℃ resulted in the conversion of the malonylglucoside form to the glycoside form, whereas degradation, instead of conversion, of isoflavones occurred at 143 ℃. After the heat treatment at 121 ℃, the content of aglycone isoflavones in soymilk was significantly increased by 50% when compared with raw soymilk, thus improving the quality of soymilk. Compared with the other treatment temperatures, high-temperature short-time sterilization could reduce the degradation of isoflavones and increase the content of aglycone isoflavones, and was more suitable for the industrial production of soymilk.

863科技计划项目（2010AA101505）