Effect of Exogenous Addition of Tea or Pear Juice on the Quality of Meizhan Black Tea

In order to explore the effect of exogenous addition of tea or pear juice on the quality of Meizhan Gongfu black tea, fresh leaves of Meizhan cultivars were used as raw material to process Gongfu black tea. During the process, tea juice or pear juice was added with the ratio of tea:tea juice or pear juice was 2:1 (kg:L), and then the overall sensory quality, main taste and aroma substances of the obtained Gongfu black tea were analyzed. The Congfu black tea with no addition during the process was considered as control samples. The results showed that exogenous addition of both tea juice and pear juice could significantly (P<0.05) reduce the contents of epigallocatechin-3-gallate (EGCG), epicatechin-3-gallate (ECG), epigallocatechin (EGC) and epicatechin (EC), and increase the content of theaflavins. The soluble sugar content of Gongfu black tea made by exogenous pear juice was 92.53% and 95.31% higher than that of control and exogenous tea juice, respectively, which enhanced the sweetness of the finished tea soup. Exogenous addition of tea juice could significantly increase the contents of amino acids, caffeine, gallic acid, tea pigments and volatile compounds in Gongfu black tea, among which, the total amount of alcohols, aldehydes, esters and ketones were the highest, and the total amount of volatile compounds was 6.36% and 74.99% higher than that in the control samples and Gongfu black tea prepared by exogenous addition of pear juice, respectively. Geraniol with a characteristic floral aroma and the content in tea juice treatment was 15.73% and 79.64% higher than that in control and pear juice treatment, respectively, and its finished tea aroma showed obvious fruity aroma. Therefore, this study showed that exogenous addition of tea juice could improve the taste and aroma quality of Meizhan Gongfu black tea.