金佛手酵素发酵过程中有机酸及其体外抗氧化性能分析

以金佛手为主要原料制备食用植物酵素,对其自然发酵过程中体外抗氧化性能、有机酸组成及含量的变化进行研究。结果表明,金佛手酵素发酵过程中超氧自由基清除率、羟基自由基清除率和ABTS自由基清除率总体呈上升趋势,DPPH自由基清除率和还原力呈先上升后下降再缓慢上升的变化。金佛手酵素发酵5~15 d以L-苹果酸和柠檬酸为主,发酵40~90 d期间以乳酸、乙酸和L-酒石酸为主,此外还含有莽草酸、抗坏血酸、琥珀酸和草酸;发酵过程中,总有机酸含量呈先上升后下降再上升的趋势,发酵90 d时达到最高,为(9.600±0.18) mg/mL,相较发酵5 d时增长105.47%。在类间距离15处,聚类分析将发酵阶段归为2类,将有机酸种类归为3类;羟基自由基清除率和超氧自由基清除率与乳酸含量呈极显著(P<0.01)正相关(相关系数为0.885和0.680)。本研究揭示了金佛手酵素发酵过程中有机酸组成及含量、体外抗氧化性能的变化规律,为金佛手酵素的精准制备提供了理论参考。

Analysis of Organic Acids and Antioxidant Activity in Vitro of Citrus medica Jiaosu during Fermentation Process

Changes in the composition of organic acids and in vitro antioxidant activity of Citrus medica Jiaosu were investigated.During fermentation,scavenging rate on superoxide radical,hydroxyl radical and ABTS radical showed an increasing trend generally.DPPH radical scavenging rate and reducing power initially increased,then decreased,and gradually increased afterwards.The main organic acids of Citrus medica Jiaosu were L-malic acid and citric acid during 5~15 d fermentation,while they were lactic acid,acetic acid and L-tartaric acid during 40~90 d.Meanwhile,shikimic acid,ascorbic acid,succinic acid and oxalic acid were found in Citrus medica Jiaosu.The amount of total organic acid increased firstly,then decreased and then increased again until reaching its peak of(9.600±0.18)mg/mL at 90 d,growing by 105.47%compared with the amount in Citrus medica Jiaosu at 5 d.The different time points and species of organic acids were classified into two and three groups respectively by cluster analysis when rescaled distance cluster was 15.Both superoxide radical and hydroxyl radical scavenging rate showed extremly(P<0.01)significant positive correlation with the contents of lactic acid(the spatial correlation coefficient was 0.885 and 0.680 respectively).The research results revealed the changes in the composition of organic acids and in vitro antioxidant activity of Citrus medica Jiaosu,and provided a theoretical reference for precision preparation of Citrus medica Jiaosu.