野菊花60%乙醇提取物的酚类成分组成及其清除自由基和防霉变能力分析

Analyses on phenolic compositions,abilities of scavenging free radicals and mildewproof of 60% ethanol extract from Dendranthema indicum flower

对野菊〔Dendranthema indicum（L.） Des Moul.〕花的60%乙醇提取物中酚类成分的组成与含量进行了分析,并研究了该提取物对.O^2-、.OH和DPPH自由基的清除能力以及防牛奶霉变的能力。结果表明,野菊花60%乙醇提取物主要含有黄酮类成分和一定量的酚酸类成分;酚酸类成分中绿原酸和咖啡酸的含量分别为20.74 mg.g-1和1 420.57μg.g-1;总黄酮含量为490.50 mg·g^-1,其中槲皮素、木犀草素、芹菜素、刺槐素和蒙花苷的含量分别为31.05、22.67、23.09、30.71和107.23 mg·g^-1,分别占总黄酮含量的6.33%、4.62%、4.71%、6.26%和21.86%。该提取物对.O2^-、.OH和DPPH自由基均有一定的清除能力,在实验设置的浓度范围内,对3种自由基的清除率与该提取物浓度基本呈正相关关系,回归方程分别为y=0.273x＋38.540、y=1.208x＋2.761和y=2.032x＋45.330,IC50分别为41.98μg.mL-1、39.11 mg·mL^-1和2.30 mg·mL^-1,其中对DPPH自由基的清除能力最强,且其IC50略高于VC。在牛奶中添加一定量的野菊花60%乙醇提取物（质量体积分数0.012 5%-0.2%）,牛奶中的各级霉斑数量、病情指数以及霉菌孢子数均低于空白处理组,且该提取物的这种防霉变能力与其浓度呈一定的正相关关系;其中0.2%的野菊花60%乙醇提取物的防霉变能力高于质量体积分数0.01%山梨酸钾。实验结果显示,野菊花60%乙醇提取物具有较高的抗氧化能力和显著的防霉变能力,可作为食品防腐剂进行开发利用。

Compositions and contents of phenolic compounds in 60% ethanol extract from Dendranthema indicum（L.） Des Moul.flower were analyzed,and its scavenging ability to free radicals of ·O^2-,·OH and DPPH and its mildewproof ability to milk were also studied.The results show that the 60% ethanol extract mainly contains flavonoids and a certain amount of phenolic acids.In phenolic acids,contents of chlorogenic acid and caffeic acid are 20.74 mg·g^-1 and 1 420.57 μg·g-1,respectively.Total flavonoids content in the extract is 490.50 mg·g^-1,in which contents of quercetin,luteolin,apigenin,acacetin and linarin are 31.05,22.67,23.09,30.71 and 107.23 mg·g-1,accounting for 6.33%,4.62%,4.71%,6.26% and 21.86% of total flavonoids content,respectively.The extract has a certain scavenging ability to free radicals of ·O^2-,·OH and DPPH,and the scavenging rate generally appears a positive correlation with the extract concentration in concentration range of each experiment.The linear regression equations between scavenging rate and concentration of the extract are y=0.273x＋38.540,y=1.208x＋2.761 and y=2.032x＋45.330,respectively,and IC50 of the extracts to ·O^2-,·OH and DPPH are 41.98 μg·mL-1,39.11 mg·mL^-1 and 2.30 mg·mL^-1,respectively.In which,the scavenging ability to DPPH free radical is the strongest,and its IC50 is slightly higher than that of VC.When a certain amount of the extract（0.012 5%-0.2%） added in milk,mildew spot number,disease index and spore number in the milk all are lower than those of the blank group,and the mildewproof ability has a positive correlation with the extract concentration.And the mildewproof ability of 0.2% extract is high than that of 0.01% potassium sorbate.It is suggested that 60% ethanol extract from D.indicum flower has a stronger oxidation resistance and a significant mildewproof ability,so it can be further exploited and utilized as food antiseptic.