大豆肽的制备及其美拉德反应产物特性研究

本文以高温大豆粕为原材料,模拟酱油制曲工艺,通过发酵和酶解技术制备大豆肽,研究大豆肽及其美拉德反应产物的特性。通过比较其蛋白质回收率、DPPH自由基清除率等抗氧化指标、褐变程度及其肽分子量分布情况,深入研究了发酵酶解工艺和酶解时间对大豆肽及其美拉德产物抗氧化特性的影响。研究发现,发酵和酶解处理均可显著提升高温大豆粕的蛋白质回收率和抗氧化活性,在酶解时间为24 h时大豆粕的回收率达到最大值77.21%,此时大豆粕酶解产物的DPPH自由基IC50值和还原力(A700)分别为0.77 mg/m L和0.16。而美拉德反应则可以进一步提升大豆粕酶解产物的抗氧化活性。另外美拉德反应过程中分子质量较大的组分热降解反应比较剧烈,而小分子寡肽则比大分子多肽具有更高的美拉德反应活性。

Preparation of Soybean Peptides and Characteristic Study of Their Maillard Reaction Products

In this paper, the technique of using koji to produce soy sauces was simulated, soybean peptides were prepared by fermentation and enzymatic hydrolysis using high-temperature soybean meals as raw materials, and the properties of soybean peptides and their Maillard reaction products were studied. An in-depth analysis of the effects of fermentation, enzymolysis, and enzymolysis time on the antioxidant activities of soybean peptides and their Maillard reaction products was conducted through comparison of their protein recoveries, antioxidant indicators as DPPH scavenging capacities, degrees of browning and molecular weight distributions. The results showed that both fermentation and enzymolysis could significantly increase the protein recoveries and antioxidant activities of the soybean peptides prepared from soybean meals. The highest protein recovery was 77.21% after an enzymolysis time of 24 h, and the half-inhibitory concentration (IC50) of the 2,2-diphenyl-1-picryhydrazyl (DPPH)-scavenging capacity and reducing power (A700) of the enzymatic hydrolysate of soybean were 0.77 mg/mL and 0.16, respectively. However, the antioxidant activity of the Maillard reaction products could be further enhanced. Additionally, the thermal degradation of higher-molecular-weight components during the Maillard reaction was more intense, while the small molecules (oligopeptides) had higher Maillard reactivity than the large molecules.