核桃青皮总酚含量测定和抗氧化能力研究

目的]测定核桃青皮80%乙醇提取物及其经大孔树脂HP-20分段后的各纯化部分的总酚含量,评价其各部分的抗氧化能力,并分析总酚含量与抗氧化能力的关系。方法]采用福林-酚比色法,测定总酚含量,通过DPPH·和ABTS·自由基清除法评价其抗氧化能力。结果]核桃青皮提取物及其各纯化部分均表现出一定的抗氧化性,其中Fr.2(20%甲醇洗脱部分)、Fr.3(40%甲醇洗脱部分)部分的IC50(半数抑制浓度)均高于VC(抗坏血酸),Fr.4(60%甲醇洗脱部分)和Ext.(80%乙醇提物部分)与VC相当,并且总酚含量和抗氧化能力呈正相关。结论]经过大孔树脂HP-20处理后的核桃青皮乙醇提取物,其总酚的含量得到了富集,为进一步研究核桃青皮各部分的物质成分提供了依据。同时表明核桃青皮的提取物可以作为天然的抗氧化剂应用于食品、医疗、化妆品、保健品等行业。

Determination of Total Phenols Content and Antioxidant Capacity of Walnut Green Husks

Objective]To determine the content of total phenols in the 80% ethanol extracts of walnut green husk and its several purification sections isolated and purified by HP-20,evaluate the antioxidant capacity of the extracts,and analyze the relationship between the content of polyphenols and antioxidant capacity.Method]The content of total phenolswere determined by the method of Folin-phenol,and its extract antioxidant capacities were compared by DPPH· and ABTS· radical scavenging.Result]All the extracts showed antioxidant activity,in which the IC50(half maximal inhibitory concentration) value of Fr.2(the elution fraction of 20% methanol) and Fr.3(the elution fraction of 40% methanol) was better than that of VC(ascorbic acid),Fr.4(the elution fraction of 60% methanol) and Ext.(the extract portion of 80% ethanol) was similar to VC,and polyphenol content and antioxidant capacity was positive correlation.Conclusion]The content of polyphenols in the ethanol extract of walnut green husk can be enriched by HP-20,which will provide a basis for the further study of the material composition of the walnut green husk.The extract of walnut green husk can be used as a natural antioxidant used in food,health care,cosmetics,health products and other industries.