The mechanism of operation of climatic factors in the biogenesis of tea flavour

Response of tea quality parameters to time of year and nitrogen fertiliser

“…Seasonal variations in shoot growth have been associated with seasonal variations in quality. The observed quality fluctuations in Sri Lanka (Wickremasinghe 1974;Fernando and Roberts 1984), Malawi and Argentina (Malec and Vigo 1988) may therefore not exist under Kenyan growth conditions.…”

“…In tea (Camellia sinensis L 0 Kuntze) growing countries where there are large seasonal climatic variations, changes in growth patterns have been demonstrated to cause large variations in chemical composition of green leaf Hilton et a1 1973) and hence quality of made black tea (Wickremasinghe 1974;Fernando and Roberts 1984;Malec and Vigo 1988). The climatic variations in such countries make it impractical to produce tea uniformly throughout the year.…”

“…The studies in Sri Lanka (Wickremasinghe 1974;Fernando and Roberts 1984) assumed that seasons would only have an impact on the volatile flavour compounds (VFC); in Argentina, Malec and Vigo (1988) concentrated on the theaflavins (TF), thearubigins (TR) and caffeine. From the variations in the catechins (flavonols) composition with seasons, it was assumed in Malawi that the TF levels would similarly change when seasons changed.…”

Tea aroma

“…The compounds produced from carotenes have a major effect on the aroma of tea. Flavoury teas are normally produced from green leaf with high carotene contents (Wickremasinghe, 1974).…”

“…Even slight changes in climatic factors can result in noticeable changes in the composition of the aroma complex (Wickremasinghe, 1974;Takeo, 1983a;Mahanta et al, 1988a;Owuor et al, , 1990. Teas grown at higher altitudes tend to have higher concentrations of aroma compounds (Owuor et al, , 1990Mahanta et al, 1988) and superior flavour, as measured by the flavour index (Owuor et al, , 1990 or the ratio of terpenoid to non-terpenoid compounds (Mahanta et al, 1988).…”