限制性酶解燕麦蛋白功能特性和抗氧化活性

The Functional Properties and Antioxidant Activity of Oat Protein by Restricted Enzymatic Hydrolysis

利用碱性蛋白酶限制性酶解燕麦蛋白,研究了不同水解度(DH)酶解物的溶解性、乳化性、乳化稳定性及对DPPH自由基清除率。试验结果表明,限制性酶解后燕麦蛋白的功能性质有了很大提高。水解初期,随着DH增加,溶解性增大,当DH为15%,pH 8时,溶解度达到79.78%,比原料蛋白在此pH下的溶解性提高了163.91%。乳化性随DH增加而降低,当DH为5%,pH 8时,乳化性达到0.852,比原料蛋白在此pH下的乳化性提高了56.04%。乳化稳定性的变化规律与乳化活性相反,当DH为20%,pH 8时,乳化稳定性达到73.14%,比原料蛋白在此pH下的乳化性提高了59.76%。酶解物对DPPH自由基清除率随着DH增加而变大,DH 5%、DH 10%、DH 15%和DH 20%酶解物对DPPH自由基清除率的IC50分别为6.274,6.145,6.050和5.640 mg·mL-1,而且浓度与清除率呈现出明显的剂量效应。

The solubility,emulsifying property,emulsifying stability and DPPH free radical scavenging rate of oat protein hydrolysates with different hydrolysis degrees(DH)were studied by restrictive enzymatic hydrolysis with alkaline protease.The results showed that the functional properties of oat protein were greatly improved after restriction enzymatic hydrolysis.At the initial stage of hydrolysis,the solubility increased with the increase of DH.When DH was 15%and pH was 8,the solubility reached 79.78%,which was 163.91%higher than that of raw protein at this pH.The emulsifying property decreased with the increase of DH.When DH was 5%and pH was 8,the emulsifying property reached 0.852,which was 56.04%higher than that of raw protein at this pH.The change of emulsion stability was contrary to emulsifying property.When DH was 20%and pH was 8,the emulsion stability reached 73.14%,which was 59.76%higher than that of raw protein at this pH.The scavenging rate of DPPH radicals by enzymatic hydrolysates increased with the increase of DH.The IC50 of the scavenging rate of DPPH radicals by DH 5%,DH 10%,DH 15%and DH 20%enzymatic hydrolysates were 6.274,6.145,6.050 and 5.640 mg·mL-1 respectively,and the concentration and scavenging rate showed obvious dose effect.