Changes in thearubigin fractions and theaflavin levels due to variations in processing conditions and their influence on black tea liquor brightness and total colour
Publication Date
2004-03-30Author
Obanda
Owuor, P Okinda
Mang’oka, Richard
Kavoi, Mutuku M
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Show full item recordAbstract/ Overview
Increase in coarser plucking standards significantly (P< 0.05) depressed levels of theaflavin
(TF; μmol/g), total colour and brightness (spectrophotometer) of black tea. But total
thearubigins (TR) TRSI, TRSII and brightness (taster) levels did not significantly (P< 0.05)
change with plucking standards. Increasing fermentation duration led to rise in TF (μmol/g),
total TR, total colour, TRSI and TRSII, liquor brightness (taster) but not liquor brightness
determined by spectrophotometer method (P< 0.05). Correlation analysis showed that total
TR and TRSII had negative correlations (r=− 0.66 and− 0.77, P< 0.01), respectively, while
total TF levels had positive correlation with taster brightness (r= 0.57, P< 0.01). Total TF level
had highest correlation with spectrophotometer liquor brightness (r= 0.87, P< 0.01) for a
single substance. TRSII and total TR gave an r of 0.86 indicating that the two groups of …
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- Department of Chemistry [326]