茶籽多糖羧甲基化修饰及其对油脂抗氧化作用研究

Carboxymethylation modification of Camellia oleifera seed polysaccharides and its antioxidant effect on oils and fats

以羧甲基化茶籽多糖对O2-·的比清除率作为茶籽多糖羧甲基化修饰的衡量指标,优化NaOH、一氯乙酸钠反应体系对茶籽多糖进行羧甲基化修饰的条件,并探讨羧甲基化茶籽多糖对油脂的抗氧化作用。通过单因素试验和正交试验分析乙醇体积分数,茶籽多糖与NaOH、一氯乙酸钠的质量比,反应温度,反应时间对羧甲基化茶籽多糖对O2-·的比清除率的影响;采用Schaal烘箱法研究羧甲基化茶籽多糖对油脂的抗氧化作用。结果表明:茶籽多糖羧甲基化修饰的最佳条件为乙醇体积分数80%,茶籽多糖与NaOH、一氯乙酸钠的质量比1∶3∶2,反应温度50℃,反应时间3 h。在最佳条件下,羧甲基化茶籽多糖对O2-·的比清除率为0.600 mL/mg,取代度为0.624。羧甲基化茶籽多糖对油脂的抗氧化作用较茶籽多糖有明显提高。茶籽多糖羧甲基化修饰有利于提高茶籽多糖的抗氧化效果。

The conditions of Camellia oleifera seed polysaccharides(COSP)modified by carboxymethylation were optimized in the NaOH and sodium chloroacetate reaction system with the specific scavenging rate of COSP carboxymethylation(COSPC)on O2-·as an index.The antioxidant effect of COSPC on oils and fats was investigated.The effects of ethanol volume fraction,mass ratio of COSP to NaOH and sodium chloroacetate,reaction temperature and reaction time on specific scavenging rate of COSPC on O2-·were analysed by single factor experiment and orthogonal experiment.The antioxidant effects of COSPC on oils and fats were investigated by Schaal oven method.The results showed that the optimal conditions of COSP modified by carboxymethylation were obtained as follows:ethanol volume fraction 80%,mass ratio of COSP to NaOH and sodium chloroacetate 1∶3∶2,reaction temperature 50℃and reaction time 3 h.Under these conditions,the specific scavenging rate of COSPC on O2-·was 0.600 mL/mg and the substitution degree was 0.624.The antioxidant effect of COSPC on oils and fats was significantly higher than that of COSP.The carboxymethylation modification of COSP could improve its antioxidant effect.