1. Analysis of chemical components in oolong tea in relation to perceived quality.
- Author
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Kunbo Wang, Fang Liu, Zhonghua Liu, Jianan Huang, Zhongxi Xu, Yinhua Li, Jinhua Chen, Yushun Gong, and Xinghe Yang
- Subjects
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TEA , *POLYPHENOLS , *GLUTAMIC acid , *AMINO acids , *REGRESSION analysis - Abstract
Properties of leaf and infusion colours, chemical components and volatile flavour compounds of oolong teas and their correlation with perceived quality score given by tea-tasting panel were analysed. The scores for appearance and infused leaf correlated strongly with concentrations of chlorophyll a (chl a), chlorophyll (chl b) and chlorophyll (chl) ( r = 0.355–0.433, P < 0.05) and the total quality score (TQS) positively correlated with concentrations of chl a, chl b and chl ( r = 0.517–0.533, P < 0.01). The perceived taste score and TQS positively correlated with the concentration of total free amino acid ( r = 0.514, 0.694, P < 0.01) and theanine ( r = 0.500, 0.684, P < 0.01). The volatile composition and their quantities varied widely among oolong tea samples. Nerolidol, indole, benzeneacetaldehyde, linalool, linalool oxide I, hexanal, benzyl nitrile, geraniol and 1-penten-3-ol were prevailing volatile compounds detected in most of oolong tea samples. Principal component analysis screened ten principal components with the first three (glutamic acid, total catechins and benzeneacetaldehyde) explaining 27.86%, 20.00% and 14.46% of the total variance, respectively. Regression analysis upon the ten principal components formulated a prediction model on the total quality score with 78.5% probability. The result showed that oolong teas could be partially classified by cluster analysis based on principal components. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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