云南晒干红茶的生化成分与品质分析

Analysis of Quality and Biochemical Components of Yunnan Sun-Dried Black Tea

为了解晒干红茶的生化成分与品质特点,分别收集10份晒干红茶样品和10份烘干红茶样品,进行感官审评与生化成分测定。感官审评发现晒干红茶具有外形色泽乌褐较润、汤色橙红明亮、滋味鲜甜爽口、花香馥郁、叶底红褐的品质特点,符合GB/T 13738.2—2017《红茶第2部分:工夫红茶》的感官品质特征;其中,晒干红茶的苦味与涩味分数显著低于烘干红茶(P<0.05)。通过偏最小二乘判别分析发现晒干红茶的苏氨酸、缬氨酸、苯丙氨酸、丝氨酸、亮氨酸、酪氨酸、天冬氨酸、异亮氨酸、组氨酸、精氨酸、没食子儿茶素没食子酸酯、芦丁含量高于烘干红茶[变异权重参数(variable importance in projection,VIP)>1,P<0.05,差异倍数(fold change,FC)>1.5];而脯氨酸、谷氨酸、γ-氨基丁酸、儿茶素没食子酸酯、花旗松素含量低于烘干红茶(VIP>1,P<0.05,FC<0.67)。综上发现晒干与烘干红茶成分与品质存在差异,因此,建议建立晒干红茶的标准,以促进该类茶叶的发展。

This study aims to clarify the biochemical components and quality of sun-dried black tea.To be specific,ten samples of black tea dried by sunlight and baking were collected,respectively,for sensory evaluation and measurement of chemical components.According to the sensory evaluation,the sun-dried black tea was dark brown,and the infusion was bright orange,with fresh sweet refreshing taste and fragrance.In addition,the infused tea leaves were red brown.All these characteristics met the standard of 'Black tea—Part 2:Congou black tea'(GB/T 13738.2—2017).The scores of bitterness and astringency of sun-dried black tea were lower than those of baked black tea(P<0.05).Partial least squares-discriminant analysis showed that content of threonine,gallocatechin gallate,rutin,valine,phenylalanine,serine,leucine,tyrosine,aspartic acid,isoleucine,histidine,and arginine in sun-dried black tea was higher than that in baked black tea [variable importance in projection(VIP)1,P<0.05,fold change(FC)1.5],while the content of proline,γ-aminobutyric acid,glutamic acid,catechin gallate,and taxifolin was lower than that in baked black tea(VIP1,P<0.05,FC0.67).In summary,content of biochemical components and sensory quality of black tea dried by sunlight and baking were different.Therefore,efforts should be made to develop the standard for sun-dried black tea and promote the development of the tea.