杨梅蛋白酶解肽抗氧化及降血糖活性的稳定性研究

Study on antioxidant and hypoglycemic activity stability from Myrica rubra peptide

以杨梅蛋白酶解肽为研究对象,考察其相对分子量分布范围,并以DPPH自由基清除活性和α-葡萄糖苷酶抑制活性为指标,分别研究了温度、p H、糖、防腐剂和金属离子等5个因素对杨梅蛋白酶解肽抗氧化及降血糖活性的影响。结果表明,杨梅蛋白酶解肽分子量范围在118.9～4552.2u,且杨梅蛋白酶解肽有较强的热稳定性及耐酸性,而在碱性条件下,抗氧化活性丧失较快而降血糖活性略微上升;糖类能显著增加其抗氧化活性,增加顺序为：葡萄糖〉乳糖〉蔗糖;苯甲酸和Na Cl对其抗氧化活性影响及苯甲酸对其降血糖活性影响都不显著（p〉0.05）,而Na Cl在1.5%～2%范围内促进了降血糖活性;Cu2＋和Zn2＋均能降低抗氧化及降血糖活性,而Mg2＋和K＋对抗氧化活性影响不显著（p〉0.05）,但Mg2＋对降血糖活性有较小增强作用,K＋影响不显著（p〉0.05）。

The stability of antioxidant and hypoglycemic activity from Myrica rubra peptide were determined with the effects of temperature,pH,saccharides,antiseptics and metal ions on the DPPH radicals scavenging activity and α-glucosidase inhibition activity assessed,but also investigated its relative molecular mass distribution. The result showed that the relative molecular mass distribution of Myrica rubra peptide range from 118.9-4552.2u with an excellent heat-resistant and heat-resistant ability. But antioxidant activity lost and hypoglycemic activity rose slightly in the alkali environment. Saccharides could increase the antioxidant activity significantly in the order of glucose 〉lactose 〉sucrose. Both benzoic acid and NaCl had no effects on antioxidant activity. Benzoic acid had no significant effects on hypoglycemic activity（p〉0.05）, but NaCl improved the hypogiycemic activity from 1.5% to 2%. Both Cu2＋ and Zn2＋ reduced the antioxidant and hypoglycemic activity. Mg2＋ and K＋ had no significant effects on antioxidant activity（p〉0.05）,but hypoglycemic activity was slightly enhanced by Mg2＋ and K＋ had no significant effects on hypoglycemic activity（p〉0.05）.