粳米鲜海椒的抗氧化活性及其对小鼠肝脏脂质过氧化作用的影响

摘要

粳米鲊海椒是以新鲜红辣椒经过破碎后与米粉等配料以一定比例混合并添加适量盐后厌氧发酵一定时间而成的一种中国西南地区地方特色的自然乳酸发酵辣椒制品.由于辣椒富含多酚,以及发酵过程中结合型多酚可能会释放等,因此研究了鲊海椒化学抗氧化活性及对肝脏脂质过氧化作用的影响.对不同发酵时段蚱海椒研究结果显示,总还原力和氧自由基吸收能力(oxygen radical absorbance capacity,ORAC)在发酵15d后即达到较高水平,其峰值分别出现在发酵15d和发酵60 d.进一步抗氧化活性分析显示,发酵15d样品清除1,1-二苯基-2-三硝基苯肼自由基的能力强于发酵60 d样品,但无显著差异(P＞0.05).细胞抗氧化作用研究显示,发酵60 d样品羰基含量显著低于对照十偶氮二异丁脒盐酸盐组(P＜0.05),对牛血清白蛋白氧化抑制率是发酵15d样品的2.38倍;红细胞溶血延迟时间随处理质量浓度增加快速下降,发酵15d样品下降速率快于发酵60 d样品,质量浓度为0.5 mg/mL时溶血延迟时间相对最长,发酵15d和60 d样品差异不显著(P＞0.5);发酵60 d样品对肝脏脂质过氧化的抑制作用显著强于发酵15d样品(P＜0.05),表明延长发酵时间有利于提升细胞抗氧化能力.相关性分析结果显示,不能用多酚含量判断样品的细胞抗氧化作用.本研究表明不能单独用化学抗氧化方法评价抗氧化能力,通过建立细胞模型综合评价食物的抗氧化性能更客观判断食物的抗氧化能力.%Fermented rice-chili,a fermented product produced by lactic acid bacteria in southwest China,is produced by anaerobic fermentation of a mixture of crushed fresh red chili,rice flour,salt and other ingredients for a certain time.Chili,rich in polyphenols,may release bound polyphenols during fermentation.Thus,antioxidant activity of fermented rice-chili in cells and its effect on lipid peroxidation in the liver of mice were studied.Results showed total reducing power and oxygen radical absorbance capacity (ORAC) of fermented rice-chili reached their maximum value at 15 and 60 d,respectively.1,1-diphenyl-2-picryl-hydrazyl (DPPH) free radical scavenging activity of fermented rice-chili at 15 d was higher but not significantly than at 60 d (P ＞ 0.05).However,fermented rice-chili at 15 d showed significantly lower (P ＜ 0.05) inhibitory effect on lipid peroxidation in the liver than at 60 d.Fermented rice-chili at 60 d had significantly lower (P ＜ 0.05) carbonyl content than the control + AAPH group,and its percentage inhibition against bovine serum albumin (BSA) oxidation was 2.38 times as high as that at 15 d.For hemolysis delay time,the sample at 15 d declined faster than that at 60 d with the difference being not significant,and the longest hemolysis delay time was achieved at 0.5 mg/mL.Polyphenol content and percentage inhibition against BSA oxidation were positively correlated (P ＜ 0.01).The antioxidant capacity of fermented rice-chili in cells could be increased by increasing fermentation time,but polyphenol content was not enough to estimate the cellular antioxidant capacity.These data suggest that chemical antioxidant tests in vitro alone are not enough to evaluate antioxidant capacity,and comprehensive evaluation of food antioxidant properties using a cell model can give more objective judgment.