Jeganathan Brasathe, Punyasiri P A Nimal, Kottawa-Arachchi J Dananjaya, Ranatunga Mahasen A B, Abeysinghe I Sarath B, Gunasekare M T Kumudini, Bandara B M Ratnayake
Department of Food Science and Technology, Faculty of Agriculture, University of Peradeniya, Peradeniya, Sri Lanka.
Institute of Biochemistry Molecular Biology and Biotechnology, University of Colombo, 00300 Colombo, Sri Lanka.
Int J Food Sci. 2016;2016:6057434. doi: 10.1155/2016/6057434. Epub 2016 Jun 6.
Flavonol glycosides in tea leaves have been quantified as aglycones, quercetin, myricetin, and kaempferol. Occurrence of the said compounds was reported in fruits and vegetable for a long time in association with the antioxidant potential. However, data on flavonols in tea were scanty and, hence, this study aims to envisage the flavonol content in a representative pool of accessions present in the Sri Lankan tea germplasm. Significant amounts of myricetin, quercetin, and kaempferol have been detected in the beverage type tea accessions of the Sri Lankan tea germplasm. This study also revealed that tea is a good source of flavonol glycosides. The Camellia sinensis var. sinensis showed higher content of myricetin, quercetin, and total flavonols than var. assamica and ssp. lasiocalyx. Therefore flavonols and their glycosides can potentially be used in chemotaxonomic studies of tea germplasm. The nonbeverage type cultivars, especially Camellia rosaflora and Camellia japonica Red along with the exotic accessions resembling China type, could be useful in future germplasm studies because they are rich sources of flavonols, namely, quercetin and kaempferol, which are potent antioxidants. The flavonol profiles can be effectively used in choosing parents in tea breeding programmes to generate progenies with a wide range of flavonol glycosides.
茶叶中的黄酮醇苷已被定量为苷元、槲皮素、杨梅素和山奈酚。上述化合物在水果和蔬菜中的存在与抗氧化潜力相关,已有很长时间的报道。然而,关于茶叶中黄酮醇的数据很少,因此,本研究旨在设想斯里兰卡茶树种质中一组代表性种质的黄酮醇含量。在斯里兰卡茶树种质的饮料型茶叶种质中检测到了大量的杨梅素、槲皮素和山奈酚。本研究还表明,茶是黄酮醇苷的良好来源。中国种茶树的杨梅素、槲皮素和总黄酮含量高于阿萨姆种和大叶种。因此,黄酮醇及其糖苷可潜在地用于茶树种质的化学分类研究。非饮料型品种,特别是玫瑰茶和红茶以及类似中国类型的外来种质,在未来的种质研究中可能有用,因为它们是黄酮醇(即槲皮素和山奈酚)的丰富来源,而黄酮醇是有效的抗氧化剂。黄酮醇谱可有效地用于茶叶育种计划中选择亲本,以培育出具有广泛黄酮醇苷的后代。