水解度对蚕蛹蛋白酶解物的物化特性和抗氧化能力的影响

对蛋白质进行适度酶解是改善动植物蛋白原料的物化性质和提高其生理活性的常用方法.研究了水解度对蚕蛹蛋白的溶解性、乳化性、起泡性等物化性质的影响,以及水解度对蚕蛹蛋白的还原力,对DPPH自由基、超氧阴离子自由基和羟基自由基的清除能力等抗氧化特性的影响.实验结果表明,蚕蛹蛋白经适度酶解后溶解性得到显著改善,且水解度越大溶解性越好.蚕蛹蛋白经酶解后乳化性与乳化稳定性均降低,但起泡性和起泡稳定性增强,水解度增至5%时,起泡性和起泡稳定性达到最高值,继续增大水解度,反而下降.蚕蛹蛋白经酶解后抗氧化性显著提高,水解度为5%时,还原力和对DPPH自由基和羟基自由基的清除能力最高,水解度为15%时,对超氧阴离子自由基的清除能力最高,继续增加水解度,抗氧化能力反而下降.这说明,对蛋白质原料进行酶解改性时,不能简单的追求高水解度,而应根据产品的要求控制合适的水解度,过度水解是无益的.

Study on Functional Properties and Antioxidant Activity of Different Degree of Hydrolysates of Silkworm Pupa Polypeptide

Enzymatic modification is an effective method for the improvement of the functional properties and physiological activities of plant and animal proteins. In this study, the effect of the degree of hydroly- sis （DH） on the functional properties and antioxidant activities of the silkworm pupa protein hydrolysates were investigated. Enzymatic hydrolysis significantly improved the solubility of silkworm pupa protein and the solubility was increased with the increasing DH. Enzymatic hydrolysis decreased the emulsifying ac- tivity and emulsifying stability but increased the foaming ability and foaming stability, and the maximum foaming ability and foaming stability were obtained when DH was 5%. Enzymatic hydrolysis significantly improved the antioxidant activities. When DH was 5% , the reducing power, DPPH radical scavenging a- bility, and hydroxyl radical scavenging ability reached their maximum. However, the maximum of super- oxide anion free radical scavenging capacity was achieved at the DH of 15%. The results indicate the ap- propriate DH is very important for the functional properties of protein hydrolysates.