不同苦荞蛋白酶解产物抗氧化活性研究

以苦荞蛋白作为底物,采用碱性蛋白酶Alcalase 2.4 L、木瓜蛋白酶、胃蛋白酶、胰蛋白酶以及胃蛋白酶加胰蛋白酶模拟体内蛋白消化,制备苦荞麦蛋白水解物。采用DPPH及ABTS~+·法比较不同的蛋白水解物与水解前苦荞蛋白的体外抗氧化活性。结果表明:不同蛋白酶水解产物水解度由高到低的顺序为:碱性蛋白酶胃蛋白酶~胰蛋白酶胃蛋白酶木瓜蛋白酶胰蛋白酶,其中碱性蛋白酶水解苦荞蛋白水解度达29.95%。苦荞蛋白本身具有一定的抗氧化能力,其中DPPH清除率及ABTS~+·清除率最高分别达71.91%及11.25%,但均显著低于阳性对照Vc。随着水解程度的增加,苦荞蛋白水解产物抗氧化能力逐渐增强。其中,以碱性蛋白酶酶解产物抗氧化活性最高,其DPPH清除率及ABTS~+·清除率最高分别为91.65%(0.5 mg/mL)及16.67%(1 mg/mL),均显著高于原苦荞蛋白。其中,碱性蛋白酶水解产物的DPPH自由基清除率在高浓度(0.5mg/mL)条件下,与阳性对照Vc持平。同时碱性蛋白酶酶解产物抗氧化性(DPPH清除率及ABTS~+·清除率)显著优于其他蛋白酶解产物。因此,苦荞麦蛋白采用碱性蛋白酶解制备苦荞水解产物可作为天然的抗氧化剂。

Antioxidant activity of different protein hydrolysates from tartary buckwheat

Tartary buckwheat protein hydrolysate was prepared with tartary buckwheat protein as substrate, hydrolyzed by Alcalase 2.4 L, papain, pepsin, trypsin, and combination of pepsin and trypsin to simulate in vitro digestion. The antioxidant properties of different protein hydrolysates were tested by DPPH and ABTS+·scavenging ability. The result showed that the order of the degree of hydrolysis of different proteases hydrolysates was: Alcalase 2.4 L > pepsin+trypsin >pepsin> papain>trypsin. The tartary buckwheat protein hydrolysate by Alacalase 2.4 L had highest degree of hydrolysis of 29.95%. The original tartary buckwheat had antioxidant ability. The highest scavenging ability of DPPH and ABTS+·of original tartary buckwheat protein was 71.91% and 11.25%, but both of them were significantly lower than positive control group of Vc. With the increase of hydrolysis degree, the antioxidant ability of protein hydrolysate increased. The protein hydrolysates from Alcalase 2.4 L showed the highest antioxidant ability, which was significantly higher than original tartary buckwheat protein. The highest scavenging ability of DPPH and ABTS+·of protein hydrolysates from Alcalase 2.4 L were 91.65% (0.5 mg/mL) and 16.67% (1 mg/mL), respectively. At high concentration (>0.5 mg/mL), protein hydrolysates from Alcalase 2.4 L showed no significant difference compared with positive control of Vc. Besides, protein hydrolysates from Alcalase 2.4 L showed significantly higher antioxidant properties than other protein hydrolysates. Therefore, the tartary buckwheat protein hydrolysate by Alcalase 2.4 L could be used as an antioxidant.