茶组植物新资源-元宝山茶的主要化学成分及其抗氧化活性

Chemical Components and Antioxidative Activities of Camellia yungkiangensis var.yuanbaoshanica-A New Resources of Camellia sinensis

以茶组植物新资源元宝山茶和九万山大茶树(对照)的鲜叶固定样、红茶工艺样和绿茶工艺样为材料,分析两种茶主要品质化学成分的差异,采用DPPH、FRAP和ABTS三种方法对比分析二者的抗氧化活性。结果表明,元宝山茶鲜叶固定样茶多酚、可溶性糖、黄酮、可可碱、没食子酸、DL-C的含量分别为31.33%、10.96%、0.41%、2.84%、0.21%、9.28%,显著高于对照茶树鲜叶固定样(p<0.05),其游离氨基酸、咖啡碱、总儿茶素、EGC、EGCG、GCG、ECG含量分别为1.17%、0.39%、12.55%、0.21%、1.45%、0.12%、0.86%,显著低于对照九万山大茶树鲜叶固定样(p<0.05)。DPPH IC_(50)和ABTS IC_(50)以两个绿茶工艺样最小,其次是两个鲜叶固定样;FRAP IC_(50)以元宝山茶绿茶工艺样最小(225.21μg/mL),以对照九万山大茶树红茶工艺样最大(862.63μg/mL)。元宝山茶各样品的DPPH IC_(50)小于ABTS IC_(50)和FRAP IC_(50),均以FRAP IC_(50)最大。相关性分析表明,茶多酚、黄酮和儿茶素类物质的含量与各供试样品的抗氧化活性呈极显著相关(p<0.01)。因此,与茶(Camellia sinensis)相比元宝山茶属于高茶多酚、高DL-C、高可溶性糖、高可可碱、低咖啡碱的特异性资源,具有较强的体外抗氧化活性。

Camellia yungkiangensis var.yuanbaoshanica(a new resource in Sect.Thea plants)and the Camellia sinensis plants grown locally in Jiuwan Mountain was compared in terms of their main quality-controlling components,using fresh leaf,black tea,and green tea samples.Additionally,the antioxidative activities of the two plants were analyzed using 1,1-diphenyl-2-picrylhydrazyl(DPPH),ferric reducing antioxidant power(FRAP),and 2,2ʹ-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS)assays.The contents of the tea polyphenols,soluble sugars,flavonoids,theobromine,gallic acid,and DL-catechin(DL-C)in the fresh leaf sample of Camellia yungkiangensis var.yuanbaoshanica were 31.33%,10.96%,0.41%,2.84%,0.21%,and 9.28%,respectively,all of which were significantly higher than those of Camellia sinensis(p<0.05).By contrast,the contents of free amino acids,caffeine,total catechins,epigallocatechin,epigallocatechin gallate,gallocatechin gallate,and epicatechin gallate in the fresh leaf sample of Camellia yungkiangensis var.yuanbaoshanica were 1.17%,0.39%,12.55%,0.21%,1.45%,0.12%,and 0.86%,respectively,which were significantly lower than those observed for Camellia sinensis(p<0.05).Moreover,for both plants,the IC_(50) values of the green tea samples against DPPH and ABTS were the lowest,followed by those of the fresh leaf samples.The FRAP IC_(50) value of the green tea sample of Camellia yungkiangensis var.yuanbaoshanica was the lowest(225.21μg/mL)whereas that of the black tea sample of Camellia sinensis was the highest(862.63μg/mL).Furthermore,the DPPH IC_(50) values of all three types of Camellia yungkiangensis var.yuanbaoshanica samples were all smaller than the respective ABTS and FRAP IC_(50) values,with the FRAP IC_(50) values being the highest.Additionally,the correlation analysis revealed that the tea polyphenol,flavonoid,and catechin contents were significantly related to the antioxidative activities of all the samples(p<0.01).In summary,Camellia yungkiangensis var.yuanbaoshanica was shown to be a special resource with high contents of tea polyphenols,DL-C,soluble sugars,and theobromine and a low content of caffeine.Importantly,it exhibited stronger antioxidative activities in vitro compared to Camellia sinensis.