为了研究谷朊粉酶解产物中发挥抗氧化活性的肽片段,采用截留不同相对分子质量的超滤膜对谷朊粉酶解产物进行初步分离富集,并通过测定各级多肽的亚铁离子螯合能力、对亚油酸的自氧化抑制能力以及对ABTS自由基的清除能力来评价其体外抗氧化能力.结果表明:抗氧化能力由弱到强依次为:大于10 000＜10 000～5 000＜小于5 000.对于相对分子质量在5000以下的组分,当质量浓度为0.2、0.4 mg/mL时,亚铁离子螯合能力是超滤前样品的2倍左右;对亚油酸自氧化的抑制能力在36 h后比其它相对分子质量片段的组分效果明显;而当质量浓度为4 mg/mL时,TEAC值达到1.45 mmol/L Trolox;并且由高效液相色谱法对其相对分子质量进行分析发现,小分子肽占了绝大部分,说明抗氧化肽主要集中在相对分子质量2 000以下.%In order to study the active fraction of wheat gluten hydrolysates(WGH), WGH was preliminary separated and purified by using different MWCO of the ultrafiltration membrane. Different antioxidant assays in vitro such as ferrous ion-chelating activity, inhibition of linoleic acid emulsion peroxidation and 2, 2 -azinobis (3-ethylbenothiazoline-6-sulphonic acid) diammonium salt (ABTS) radical scavenging activity, were employed to evaluate the antioxidant activities of the obtained wheat gluten hydrolysate. It was found that the antioxidant activity of the WGH can be arranged in the following order: over 10KD＜10KD-5KD＜below 5KD. For the fraction which molecular weight was below 5KD, when the concentration was set at 0.2 or 0.4 mg/mL, the ferrous ion-chelating activity was about as twice as the sample which was not treated by ultrafiltration; in the linoleic acid system, a longer induction time made a significant decrease of lipid peroxidation, especially after 36h, gaps began to widen; and also when the concentration was set at 4mg/mL, the TEAC value was up to 1.45mmol/L Trolox. And it was found that small molecular weight peptides accounted for the most by the high performance liquid chromatography analysis of its molecular weight, it showed that antioxidant peptides concentrated in the following 2KD.
展开▼
