Abstract:
Four special early raw tea cultivars (Wuniuzao, Chuancha No.3, Fuxuan No.9 and Mingshan 213) were selected from Sichuan tea area to study the effect of frost in early spring on the amount of growth, the biochemical composition and sensory quality of the new shoots.Length and weight of new shoots which were under normal condition or suffered from 1-level frost damage were observed, the main biochemical composition of these shoots was determined, and the sensory quality of tea samples was reviewed, the effects of frost, biochemical composition and sensory quality of new shoots in different tea cultivars were compared.The results showed that: compared to normal tea samples, the length, weight and main biochemical composition of frozen tea samples showed a downward trend, in which water extracts, amino acids, polyphenols, caffeine declined by 1.72%-7.76%, 4.29%-10.26%, 3.82%-20.06%, 2.21%-4.46%, respecytively;the total amount of free amino acid and catechin decreased by 3.42%-8.17%, 9.06%-21.78%.Frost stressed significantly influenced amino acid content, total free amino acid and catechins quality index.Sensory evaluation results showed that the quality of all frozen samples decreased.The results also showed that 1-level frost in early spring affected the biochemical composition and sensory qulity more in Fuxuan No.9 and Mingshan 213 than Chuancha No.3 and Wuniuzao.