Biochemical Characteristics of Tea {Camellia L. spp.) Germplasm Accessions in Sri Lanka: Correlation between Black Tea Quality Parameters and Organoleptic Evaluation

Abstract

Biochemical composition of tea leaf {Camellia L. spp.) is dependent on climatic conditions and the genetic
makeup of the plant. Many attempts have been focused to identify various biochemical compounds responsible for quality.
Although, currently about 500 germplasm accessions are being maintained in the Tea Research Institute of Sri Lanka, these
accessions are not adequately evaluated for biochemical components present in processed black tea. This is the first attempt
to quantify various black tea biochemical compounds viz., theailavins, thearubigins, polyphenols, amino acids, total catechins
and caffeine content in a range of germplasm accessions and to correlate with organoleptic parameters such as infused leaf
colour, liquor colour, strength, liquor quality and total quality scores using correlation analysis. A strong positive correlation
(P less than 0.001) of theaflavins with brightness, total catechins, infused leaf colour, liquor quality and total quality scores was
observed. Principal Component Analysis (PCA) based on biochemical parameters and tasters' evaluation separated thirty five
tea accessions into four groups. These groups also depicted a relationship with their origin and ancestry. First component of PC
analysis accounted for 43.0% variability while second component accounted for 13.3% of the total variability. The significant
variation of biochemical compounds detected in the present study indicates the wider diversity of tea germplasm in terms of its
biochemical components present in black tea in Sri Lanka. Results could be used to facilitate establishing inherent biochemical
constituents that reflect quality of black tea that provides early selection criteria to speed up the tea breeding programriie.