糖基化及酶解对大豆蛋白功能性质的影响

Effect of glycosylation and limited hydrolysis on the functional properties of soybean protein isolate

天然蛋白质不具有所有期望的功能性质,而糖基化和酶解修饰能够改善蛋白质某些功能性质。在壳寡糖存在的条件下,利用转谷氨酰胺酶的酰基转移作用,对大豆分离蛋白进行糖基化修饰,得到糖基化产物。随后用碱性蛋白酶制备水解度分别为1%、2%、4%的酶解产物。对修饰产物的热特性、溶解性、乳化性等进行了分析。结果表明,糖基化产物及其酶解产物的功能性质发生了显著的变化,相对于大豆分离蛋白,糖基化产物的乳化稳定性提高。随后的酶解显著提高了糖基化大豆蛋白的一些功能性质,水解度为4%的糖基化产物的溶解性、乳化活性及持油性分别增加54.0%(pI)、19.5%和35.4%。因此,糖基化和酶解修饰相结合能够改善大豆蛋白的功能性质。

Proteins from food cannot provide all the desirable functional properties,while glycosylation and enzymatic hydrolysis can be used to improve functional properties of food proteins.Soybean protein isolate(SPI)was first glycosylated using transglutaminase in the presence of oligochitosan to produce a glycosylated soybean protein isolate(GSPI),then hydrolyzed with Alcalase to prepare various hydrolysates(1%,2% and 4% DH).Differential scanning calorimetry(DSC)and functional properties including solubility,emulsifying properties,water and oil retention capacities of the modified protein were analyzed.Results showed that the functional properties of GSPI and its hydrolysates were significantly modified.The emulsion stability of GSPI was improved in comparison with SPI.GSPI hydrolysates also showed improvement in solubility(54.0% at PI),emulsifying activity index(19.5%),and oil holding capacity(35.4%).Therefore,utilization of glycosylation and enzymatic hydrolysis combination were able to improve SPI′s functionality.