挤压膨化协同酶解工艺制备蛋壳膜多肽及其抗氧化活性和组成分析

本文以蛋壳膜为研究对象，采用挤压膨化协同酶解工艺制备壳膜多肽。以总氮回收率、D-葡萄糖醛酸提取量及抗氧化性为指标，确定最佳工艺条件为:挤压膨化温度140 ℃，螺杆转速100 r/min，水分含量20%，酶解时间6 h，加酶量12000 U/g，温度55 ℃。在该条件下总氮回收率达60.8%，D-葡萄糖醛酸提取量达12.4 mg/g，壳膜多肽的ABTS自由基清除率为29.46%（0.1 mg/mL），OH自由基清除率为26.58%（5 mg/mL），Fe2+螯合能力为50.25%（0.4 mg/mL），细胞抗氧化活性达65%（10 μg/mL）。相对分子质量分布结果表明壳膜多肽中主要成分为低聚肽（252～2435 Da），占81.8%。氨基酸组成分析结果表明壳膜肽中Asp和Glu含量较高，与抗氧化活性有关的氨基酸含量为44.70 g/100 g蛋白。因此，蛋壳膜多肽有潜力作为天然抗氧化剂应用于食品、保健品或化妆品领域。

Analysis on Antioxidant Activity and Composition of Eggshell Membrane Peptides Prepared by Extrution and Enzymatic Hydrolysis

In this study, the eggshell membrane peptides were prepared using a two-step process involved extrution and enzymatic hydrolysis. The process parameters were determined by evaluation of the total nitrogen recovery, D-glucuronic acid yield and antioxidant activity. The optimum extrution process were 140 ℃ (temperature), 100 r/min (screw rotation speed) and 20% (moisture content). And the optimum conditions of enzymatic hydrolysis were 6 h (time), 12000 U/g (enzyme amount) and 55 ℃ (temperature). Under these conditions, the total nitrogen recovery and D-glucuronic acid yield were 60.8% and 12.4 mg/g, respectively. The ABTS, OH free radical scavenging ability and Fe2+ chelating ability of the shell membrane peptides were 29.46% (0.1 mg/mL), 26.58% (5 mg/mL) and 50.25% (0.4 mg/mL), respectively. And their cellular antioxidant activity reached 65% (10 μg/mL). Results on the molecular mass distribution indicated that the main components were oligopeptides (252~2435 Da), accounting for 81.8%. Analysis on the amino acid composition suggested a high level of Asp and Glu in the peptides, and the content of amino acids related with antioxidant activity was 44.70 g/100 g protein. And thus, the shell membrane peptides have great potentials as natural antioxidants in the field of food, healthy product and cosmetic.