大豆皂苷提取工艺优化及对胃蛋白酶抑制活性

为深入研究大豆功能分子对消化酶的作用,以市售大豆为研究对象,采用超声辅助提取大豆粉中总皂苷,在超声时间、超声温度、料液比、乙醇浓度等单因素实验的基础上,选用响应面法优化超声提取大豆总皂苷的最佳工艺参数,并考察了最佳提取工艺条件下大豆总皂苷的抗氧化活性及对胃蛋白酶的抑制作用,同时深入分析酶的抑制机制。实验结果表明,大豆总皂苷的最佳提取工艺参数为料液比60 mL/g、乙醇浓度64%、超声时间20 min、超声温度41 ℃,实际提取率为(4.26±0.17)%。抗氧化实验表明,大豆总皂苷对ABTS⁺自由基和DPPH自由基均有清除效果,该皂苷具有一定的抗氧化活性。胃蛋白酶抑制实验表明,大豆皂苷对胃蛋白酶具有抑制作用,其IC₅₀为(0.585±0.021)mg/mL。酶动力学研究表明大豆皂苷与胃蛋白酶属于非竞争性抑制。研究结果为大豆总皂苷作为天然抗氧化剂和酶抑制剂的开发提供参考。

Optimization of Extraction Process and Inhibitory Activity Against Pepsin of Soybean Saponin

In order to further study the functional of soybean,functional components on digestive enzymes,the commercial soybean was taken as the research object,the total saponins from soybean powder were extracted by ultrasonic-assisted extraction.On the basis of the single factor experiments such as ultrasonic time,ultrasonic temperature,solid-liquid ratio and ethanol concentration,the response surface methodology was used to optimize the optimal process parameters for the ultrasonic extraction of total saponins from soybean powder.The antioxidant activity of soybean saponins and the inhibition on pepsin were investigated under the optimum extraction conditions,and the inhibition mechanism on the enzyme was also analyzed.The results showed that the optimal extraction conditions were solid-liquid ratio of 60 mL/g,ethanol concentration of 64%,ultrasonic time of 20 min and ultrasonic temperature of 41 ℃.The actual extraction yield was (4.26±0.17)%.The antioxidation experiments showed that the saponins had the scavenging effect on ABTS⁺free radical and DPPH free radical,and the saponins had certain antioxidant activity.The results of pepsin inhibition test showed that soybean saponin had an inhibitory effect on pepsin,and its IC₅₀was (0.585±0.021)mg/mL.The study of enzyme kinetics showed that soybean saponin and pepsin were non-competitive inhibition.This paper provides reference for the development of soybean total saponins as natural antioxidants and enzyme inhibitors.