复合改性改善大豆分离蛋白功能性质的研究

Study on Improving Functional Properties of Soybean Protein Isolate by Combined Modification

为考察糖基化接枝及酶法相结合的复合改性对于大豆分离蛋白功能性质的影响,以提高接枝度及产物乳化能力等功能性质为主要指标,制备大豆分离蛋白与麦芽糊精糖基化产物,随后采用中性蛋白酶对该产物适度酶解,得到不同水解程度的糖基化产物水解物,研究产物的乳化能力、起泡性能及抗氧化能力的变化。实验结果表明:经过接枝及适度酶解复合改性后,大豆分离蛋白的乳化能力、起泡性能及DPPH自由基清除能力均有了较大的提高,但深度的酶解有可能破坏蛋白的空间结构,降低粘度从而影响功能性质的发挥。

In this paper,effects of the combined modification of glycosylation and enzymatic hydrolysis on the functional properties of soybean protein isolate were studied. In order to improve the degree of grafting（DG） and emulsifying ability,soybean protein isolate-maltodextrin（SPI-Md）products were prepared. The glycosylation products were further hydrolyzed using Neutrase,and SPI-Md conjugate hydrolysates at different degree of hydrolysis（DH） were obtained. Effect of combined modification on emulsifying and foaming properties as well as antioxidant activity was investigated. We found that after combined modification,the emulsifying ability,foaming ability and DPPH radical-scavenging activity of soy protein isolate were significantly improved,however,deep hydrolysis may destroy the proteinic spatial structure,decrease the viscosity of the solution and thus affect the functional properties.