核桃油贮藏过程抗氧化能力的研究

以核桃油为试验原料,研究了核桃油在氧化过程中的抗氧化活性的变化。结果表明:未曾氧化的核桃油抗氧化活性较好,核桃油对DPPH·自由基的抑制率随着核桃油样品浓度的增加而不断增强,147.0 mg/m L质量浓度的核桃油清除DPPH·自由基能力为50%;340.83 mg/m L质量浓度的核桃油清除羟基自由基的能力为50%;1.0 mg/m L质量浓度的核桃油对超氧阴离子自由基的平均清除率与1.0 mg/m L质量浓度的Vc相当。而经氧化后的核桃油清除DPPH·自由基和·OH自由基的能力明显降低,相同浓度不同氧化时间的核桃油样品对超氧阴离子自由基的清除能力,随着氧化时间的增长而逐渐下降,但氧化时间越短核桃油对O2-·的抑制率越好,当氧化时间为30天时,核桃油对O2-·的平均抑制率从55.53%降到15.43%。总之,未曾氧化的核桃油的抗氧化物活性较好,随着氧化时间的增加核桃油对以上三种自由基的清除能力逐渐降低。

Research on antioxidant capacity of Walnut oil during the storage process

Taking walnut oil as the test material, its antioxidant activity in the storage process was studied. The results showed that unoxidized walnut oil showed good antioxidant ability. The inhibition rate of walnut oil on DPPH· radical increased with the increase of the concentration of walnut oil. The inhibition rate of walnut oil on DPPH· reached 50% when the concentration of walnut oil was 147.0 mg/mL; the inhibition rate of walnut oil on OH· reached 50% when the concentration of walnut oil was 340.83 mg/mL; the average inhibition rate of walnut oil and VC on O₂^.- was almost in the same level when the concentration of walnut oil and VC was 1.0mg/mL. The inhibition rate of walnut oil on DPPH· and OH· decreased obviously after it was oxidized. The scavenging activity of walnut oil in the same concentration oxidized for different time on superoxide anion radical (O₂^.-) declined gradually with the increase of the time. The average inhibition rate of walnut on O₂^.- dropped from 55.53% to 15.43% after 30 days being oxidized. In a word, the unoxidized walnut oil had good antioxidant ability. However, their antioxidant ability decreased as oxidation time increased.