Sensory Quality And Taste Quality Components Of Typical Chinese Yellow Tea

Yellow tea,also known as huangcha in Chinese,is a lightly fermented tea unique to China,and has an increasing popularity in recent years because of its pleasant mellow taste and known health benefits.This study analyses the sensory quality of chinese typical yellow tea,and established a near infrared model of taste compounds,also discusses the change of yellow tea in the process of blending.Yellow tea was divided into fresh style and mellow style on the basis of flavor characteristic,35%samples of total were fresh style,mainly from Anhui,Hubei and Sichuan provinces.65%samples of total were mellow style,mainly from Zhejiang,Shangdong and Hunan provinces.Based on sensory evaluation,12%samples were insufficient fixing,86%samples were sufficient fixing and 2%samples were over fixing.Some Sichuan and Zhejiang yellow tea were insufficient.31%samples were insufficient sealed yellowing,63%samples were sufficient sealed yellowing and 6%samples were over sealed yellowing.Anhui,Sichuan and Zhejiang yellow tea were obviously insufficient sealed yellowing.Anhui yellow tea has floral and sweet smell,and mellow-bright taste with a little grassy feel.Zhejiang yellow tea has an unique green corn smell,with mellow and refreshing taste.Sichuan yellow tea has a prominent floral and charcoal fire smell,with a thick and astringent taste.Shangdong yellow tea has very clear fire smell and dull taste.Hunan yellow tea has refreshing and sweet floral smell,with thick and mellow taste.Hubei yellow tea has sweet floral,fire and a liitle grassy smell.90%yellow bud tea was collected from Sichuan,Zhengjiang and Anhui province.Zhejiang and Anhui province also are the mainly producing area of yellow little tea.Taste components of yellow tea Show regional characteristics:For bud type yellow tea,the total amount of catechin of Hubei yellow tea samples is 219.12mg/g,significantly higher than others.The total amount of alkaloids and flavonoids of Hunan yellow tea samples are 69.93mg/g and 182.78mg/g,significantly higher than others.For bud-leaves typle yellow tea,the total amount of catechins of Hubei yellow tea samples was 244.26mg/g,significantly higher than others.The total alkaloids of Hunan yellow tea samples were 69.92mg/g,significantly higher than others.For leaves type yellow tea,the total amount of catechins of Hubei tea samples was 248.04mg/g,significantly higher than others.The total amount of alkaloids and amino acids of Hunan yellow tea samples were significantly higher than those in other regions,55.29mg/g and 23.44mg/g respectively.The content of caffeine and alkaloids of yellow tea in Hunan province are always higher than that in other areas,and the total content of catechins of yellow tea in Hubei province is always higher than that in other areas.The principal component analysis showed that the first 3 principal components could distinguish the tenderness in 82.26%degree,and GA,non-ester catechins,ester catechins content and total alkaloids,the total amount of flavonoids play an important role in the distinction between tenderness.The first 3 principal components can distinguish the origin of yellow tea 68.51%to a degree,and 13 components,such as aspartic acid,theanine,aspartic amide,quercetin 3-o-galactose,glutamate and rutin,play an important role in the differentiation of origin.The models for predicting the content of GA,CAF,EGCG,total catechins and total amino acids were combined NIRS.The range of Rc was 0.9045-0.9854.The range of RMSEC was 0.147-22.3.The Rp were 0.7121,0.8788,0.8731,0.7717,and 0.7876.The RMSEP were 0.742,4.30,18.5,47.9 and 4.17.The models can forecast the chemical components well.According to tea blending technology rules,we obtained a kind of fresh,mellow and sweet yellow tea product with the ratio of 1:1 of mellow yellow tea and thick yellow tea.And we obtained a kind of yellow little tea with fire aroma and soft taste by blending Huoshan Huangdacha and Qilu Laoganhong with the ratio of 1:1.The influence of tea blending on aroma is more obvious.The effect of blending technology on aroma of yellow tea is stronger than that on taste.