不同年份老香黄活性成分、抗氧化活性及挥发性成分分析

Analysis of active components,antioxidant activity,and volatile components of Laoxianghuang in different years

该文开展了不同贮藏年份对老香黄黄酮类化合物的组成及含量、抗氧化活性、挥发性成分的影响等研究,为老香黄的品质形成及年份鉴定提供理论支撑。选取5个不同贮藏年份(1年、2年、4年、6年、8年)的老香黄,采用HPLC探究不同年份老香黄黄酮类化合物的组成,采用DPPH法、ABTS法及铁离子还原能力(ferric reducing/antioxidant power,FRAP)进行体外抗氧化性评价,采用GC-MS进行挥发性成分的定性定量分析。结果发现,随着贮藏年限的增加,老香黄的总酚、总黄酮含量、DPPH自由基和ABTS阳离子自由基清除率及FRAP均呈上升趋势。其中相比贮藏1年,贮藏8年的老香黄的总酚、总黄酮含量分别增加了345.28%、68.35%;DPPH自由基清除率、ABTS阳离子自由基清除率及FRAP分别提高了75.19%、58.97%和148.39%。黄酮类化合物中,绿原酸、阿魏酸、儿茶素的含量随着年份的增加与老香黄的总酚、总黄酮及抗氧化性呈正相关。挥发性物质中,随着贮藏时间的延长,老香黄中的柠檬烯等萜烯类物质和1-甲基-4-(1-甲基乙基)-苯等芳香烃类物质的含量下降,而乙醇、α-萜品醇等醇类物质增加,气味随之变香醇。综上所述,随着贮藏时间的延长,老香黄总酚、总黄酮含量增加,抗氧化能力增强,气味逐渐变香醇,可为老香黄“陈久者良”提供科学依据。

In this paper,the effects of different storage years on the composition and content of flavonoids,antioxidant activity,and volatile components of Laoxianghuang(bergamot)were studied to provide theoretical support for the quality formation and age identification of Laoxianghuang.Five different storage years(one year,two years,four years,six years,and eight years)of Laoxianghuang were selected,and high-performance liquid chromatography(HPLC)was used to explore the composition of flavonoids.DPPH method,ABTS method,and ferric reducing/antioxidant power(FRAP)were used to evaluate the antioxidant activity in vitro,and gas chromatography-mass spectrometry(GC-MS)was used for qualitative and quantitative analysis of volatile components.Results showed that with the increase in storage years,the antioxidant properties of Laoxianghuang,such as total phenols,total flavonoids,DPPH free radicals,ABTS cationic radicals,and FRAP,all showed an upward trend.Compared with the one-year storage,the total phenolic and total flavonoid contents of Laoxianghuang after eight years of storage increased by 345.28%and 68.35%,respectively.The antioxidant properties of DPPH free radicals,ABTS cationic radicals,and FRAP increased by 75.19%,58.97%,and 148.39%,respectively.Among the flavonoids,the contents of chlorogenic acid,ferulic acid,and catechin increased with the years and were positively correlated with the total phenols,total flavonoids,and antioxidant properties of Laoxianghuang.Among the volatile compounds,with the prolongation of storage time,the contents of terpenes and aromatic hydrocarbons such as limonene and 1-methyl-4-(1-methylethyl)-benzene in Laoxianghuang decreased.With the increase of alcohols,such as ethanol andα-terpineol,the smell became mellow.To sum up,with the prolongation of storage time,the content of total phenols and total flavonoids of Laoxianghuang increased,the antioxidant capacity enhanced,and the odor gradually became mellow,which could provide a scientific basis for the“ageing is better”of Laoxianghuang.