Study on the Differences of Color,Taste and Aroma Constituents in White Loose Tea and White Tea Pine

To figure out the effects of pressing process in white tea quality,white loose tea (WLT) was used to produce white tea pine (WTP),then the differences between WLT and WTP in raw tea color,taste and aroma constituents were analyzed in this study. Results indicated that the WLT appearance was green,soup taste was strong and main fragrance was tenderness. However,the WTP leaves showed yellow appearance,soup taste became mellow and main fragrance was fruity and sweet. Compared with WLT,the WTP dried leaves transferred from green to red caused by the significantly increasing of red and green degree (p<0.01) and significantly decreasing of total chlorophyll,chlorophyll a and chlorophyll b (p<0.05). The aqueous extract,tea polyphenol,flavonol,theaflavin,thearubigins,theabrownin contents and tea polyphenol and amino acids ratio in WTP was significantly lower than WLT (p<0.05),whereas amino acid and soluble sugar contents significantly increased (p<0.01). After pressing process,the total alcohols aroma average relative contents and geraniol decreased about 9%. However,the linalool oxides,alkenes,ketones,esters and oxides aroma relative contents increased by 1.86%,1.89%,1.87%,3.42%,0.83%,respectively after pressing. The fragrance principal component analysis indicated that the comprehensive scores of WTP were 4~7 scores higher than that of WLT.