Study on the Effect of Cleaning Technology of Fresh Tea Leaves on the Quality of Green Tea

Abstract

This experiment was conducted to study the new shoot, bud and leaf of Fuding Dabai Tea, which was picked and purchased from Zhongfeng Tea Garden in Ya'an famous mountain area. The sensory quality, contents, pesticide residues and heavy metals of fresh leaves and green tea were studied and compared. The total soluble solids content and turbidity of water samples before and after the cleaning process were determined. The results showed that: (1) the weighted total score of sensory evaluation of finished tea added with fresh leaf cleaning technology was 91.15, which was 2.45 points higher than that of the control (without fresh leaf cleaning), and increased by 2.76%. (2) Fresh leaf cleaning process can significantly reduce the content of tea polyphenols, caffeine and water extract, and the ratio of phenol to ammonia, but has no significant effect on the content of amino acid and soluble sugar. (3) The total soluble solids of Q 2 are 4.3 times as much as Q1, and the turbidity of Q2 is 37.2 times as much as Q1. Cleaning process of fresh leaves can significantly reduce the indexes of agricultural residues and heavy metals. In conclusion, the cleaning process of fresh tea leaves can improve the sensory quality of tea to a certain extent, significantly reduce the content of bitter and astringent substances in tea leaves, effectively clean the surface impurities of fresh tea leaves, reduce pesticide residues and heavy metal content.