碱性蛋白酶限制性酶解对蓝圆鲹分离蛋白功能特性的影响

Effect of Limited Alcalase Hydrolysis on Functional Properties of Blue Round Scad(Decapterus maruadsi) Protein Isolate

以蓝圆鲹(Decapterus maruadsi)分离蛋白为原料,采用碱性蛋白酶对其进行限制性酶解,研究水解度(degree of hydrolysis,DH)对分离蛋白酶解产物溶解性、持油力、乳化性与起泡性等功能特性的影响。结果表明,碱性蛋白酶酶解产物的相对分子质量显著下降。酶解可有效提高分离蛋白的溶解性,其溶解度随DH增加而增加。与对照组相比,分离蛋白经酶解后,产物乳化性与起泡性均显著提高,并呈现先升高后降低的趋势。不同DH酶解产物在pH值为4.0时的乳化性和起泡性最低;当pH值为10.0时,DH5(DH=5%)的乳化性最高((100.9±0.7)m2/g);当pH值为7.0时,DH5起泡性最高((227.3±3.8)%)。除DH20外,其他组的持油力均有显著提高,其中DH5的持油力最高,达3.50 g/g(油/蛋白)。结果表明,一定程度的水解可以显著提高蓝圆鲹分离蛋白的功能特性。本研究为鱼蛋白在食品蛋白配料中的应用提供了一定理论参考。

In the present study, limited hydrolysis of protein isolate from blue round scads was performed with alcalase. The effects of the degree of hydrolysis(DH) on the solubility, oil-holding capacity and functional properties including emulsifying and foaming properties of hydrolysates were investigated. The results showed that the molecular masses of the proteins were remarkably decreased by alcalase hydrolysis. The solubility of the proteins was significantly improved and increased as DH increased. The emulsifying and foaming properties of the proteins significantly increased after hydrolysis, showing a trend of increased first and then decreased with increasing DH. At pH 4.0, the worst emulsifying and foaming properties were recorded for the hydrolysates at different DHs. The hydrolysate with 5% DH had the highest emulsifying capacity((100.9 ± 0.7) m~2/g) and highest foaming capacity((227.3 ± 3.8)%) at pH 10.0 and 7.0, respectively. All hydrolysates except 20% DH showed a notable increase in oil-holding capacity, with the highest value of 3.50 g/g(oil/protein) being found at 5% DH. In conclusion, a certain degree of hydrolysis could remarkably improve the functional properties of protein isolate from blue round scads. The present work provides a theoretical reference for application of fish protein isolate as a protein ingredient in foods.