试验利用黑曲霉β-葡萄糖苷酶处对豆浆进行水解处理，将结合型大豆异黄酮糖苷转化为游离型苷元。选大豆为原料，以单因素实验为基础，考察加酶量、反应时间、反应温度三个因素对豆浆中大豆异黄酮糖苷水解的影响；根据Box-Behnken实验设计原理，选取不同加酶量、反应时间、反应温度3因素3水平进行中心组合实验，建立豆浆中大豆异黄酮苷元含量的多项式回归预测模型，确定了最佳工艺参数。结果表明，最佳水解工艺条件为：加酶量0.028 U/5 mL，反应时间1.64 h，反应温度53.82 ℃，在此条件下制得豆浆大豆异黄酮苷元含量明显提高。测得大豆苷元（De）、黄豆黄素（Gle）、染料木素（Ge）的浓度分别为39.434±1.410 μg/mL、4.626±0.462 μg/mL、45.851±2.098 μg/mL。而大豆苷元（De、）黄豆黄素（Gle）、染料木素（Ge）浓度的响应面预测值分别为40.905 μg/mL、4.263 μg/mL、48.441 μg/mL，测定值与模拟值接近。优化后的工艺条件合理、可行，能明显提高豆浆中大豆异黄酮苷元的含量。

The soybean was hydrolyzed by the Aspergillus niger β-glucosidase to convert the bound soy isoflavone glycosides into a free aglycone. Using soybean as the raw material, the influence of three factors (enzyme dose for addition, reaction time, reaction temperature) on the hydrolysis of soybean isoflavone glycosides in soy milk was first investigated in single factor experiments. According to the Box-Behnken center-united experimental design principles, three factors and three levels were adopted based on the combinations of different enzyme doses, reaction times and reaction temperatures to establish polynomial regression prediction models for the isoflavone aglycone content in soy milk and determine the optimal process parameters. The results showed that optimal hydrolysis conditions were as follows: the enzyme dose, 0.028 U/5 mL; reaction time, 1.64 h; reaction temperature, 53.82 ℃. Under these conditions, the content of isoflavone aglycone in soy milk was significantly improved, with the concentrations of daidzein (De), glycitein (Gle) and genistein (Ge) being 39.434±1.410, 4.626±0.462, 45.851±2.098 μg/mL, respectively. The response surface prediction values of De, Gle and Ge were 40.905, 4.263, and 48.441 μg/mL, respectively, indicating that the measured values were close to the predicted values. The optimized process conditions are reasonable and feasible, and can allow a significant increase in the contents of isoflavone aglycones in soy milk.

国家自然科学基金项目（31460407）