为了提高大豆分离蛋白(SPI)的起泡性,对SPI经alcalase有限水解产物中不同分子大小的肽段采用谷氨酰胺转移酶TGase进行交联。结果表明:TGase交联可有效提高SPI的起泡性,特别是显著地提高了其泡沫稳定性;MW〉10ku的大分子肽当加酶量为15U/g底物且交联4h时得到最佳的泡沫稳定性为88.5%;MW〉10ku和MW〈5ku的大分子和小分子肽混合物当加酶量为50U/g(底物),交联时间为4h、大分子与小分子肽摩尔比为1:1时得到的最佳泡沫稳定性为60.3%;MW〉10ku的大分子肽交联产物的分子质量显著高于MW〉10ku的大分子肽和MW〈5ku的小分子肽(摩尔比1:1)交联产物的分子质量。
In order to improve the foaming properties of soy protein isolate (SPI), transglutaminase (TGase) cross-linking was employed for the large (Mw 〉 10 ku) and small molecular peptides (Mw 〈 5 ku) that hydrolyzed from SPI with alcalase. The results demonstrated that: TGase cross-linking could effectively improve the foaming property of SPI, especially improve the foam stability effectively; for the large molecular peptide (Mw 〉 10 ku), the optimum foam stability (88.5%) was obtained with 15 U/g substrate of enzyme and 4 h of cross-linking time; as for the mixture of large molecular peptide (Mw 〉 10 ku) and small molecular peptide (Mw 〉 5 ku), the optimum foam stability (60. 3% ) could be obtained by 50 U/g substrate of enzyme, 4 h small molecular peptide; the molecular weight of the cross-linking of cross-linking time with 1:1 molar ratio of large and products from large molecular peptide (Mw 〉 10 ku) was higher than that from the mixture of large(MW 〉 10 ku) and small (MW 〈 5 ku) molecular peptide. The research may provide certain theoretical basis for improving the foaming property of SPI by enzymatic method.