提取方法对核桃油理化性质、化学组成及抗氧化活性的影响

Effects of extraction methods on physical and chemical properties,chemical compositions and antioxidant activity of walnut oil

为了考察冷榨法、索氏法、水酶法3种提取方法对核桃油品质的影响,并挖掘影响核桃油抗氧化活性的关键化学组分,测定3种提取方法所提核桃油的理化性质、化学组成及抗氧化活性,并通过多元线性回归分析,建立核桃油抗氧化评价模型,分析影响核桃油抗氧化活性的关键化学组分.结果表明,3种提取方法对核桃油中脂肪酸及甘油酯的含量和组成影响不大,但是对总酚和黄酮含量以及油脂的理化性质和抗氧化活性影响较大.经核桃油抗氧化评价模型初步判断,亚油酸和总酚是影响核桃油抗氧化活性的关键化学组分.3种提取方法中,冷榨法所提核桃油的品质最好,水酶法次之,但是水酶法对应的核桃油得率较高,更重要的是其在提油过程中可同时制备生物活性肽,因而是一种极具应用潜力的油脂提取方法.

In order to investigate the effect of extraction methods,including cold pressing method,soxhlet method and aqueous enzymatic method,on the quality of walnut oil,and explore the key chemical components affecting the antioxidant activity of walnut oil.The physicochemical properties,chemical compositions and antioxidant activities of the walnut oils extracted by the extraction methods mentioned above were determined.In addition,the antioxidant evaluation model of walnut oil was established through multiple linear regression analysis to analyze the key chemical components,affecting the antioxidant activity of walnut oil.The results showed that the three extraction methods had little effect on the content and compositions of fatty acids and glycerides in walnut oil,but had great influences on the contents of total phenols and flavonoids,physicochemical properties and antioxidant activities of the oils.According to the antioxidant evaluation model of walnut oil,linoleic acid and total phenols were the key chemical components affecting the antioxidant activity of walnut oil.In conclusion,among the three extraction methods,the quality of walnut oil extracted by cold pressing method is the best,followed by that obtained by aqueous enzyme method.However,the yield of walnut oil extracted by aqueous enzyme method was higher than that by cold pressing method.More importantly,aqueous enzyme method can simultaneously produce bioactive peptides during the process of oil extraction,so it is a extraction method with great potential for application.