Study on the Correlation between Color Change and Quality of Mengding Yellow Bud by Different Processing Procedure

This paper studied the color of Mengding yellow bud dry tea, soup color and leaf base made by different processing procedures, and carried out pigment component detection and quality evaluation. The correlation between L ^*, a^*, b^* value of dry tea, soup color and leaf base color and the score of each evaluation factor, pigment content and total quality score was analyzed, so as to provide a certain reference for the evaluation of yellow tea dullness and color. The L^*a^*b^* values of dry tea, soup color and leaf bottom were measured by CR410 color difference meter, and then the significant analysis was made with the scores of dry tea, soup color and leaf base, and the correlation analysis was made with the scores of tea pigment, chlorophyll and total quality. The results showed that the L^*, a^*, b^* values of dry tea were significantly or extremely significantly correlated with the scores of color evaluation (P<0.05, P<0.01), the L^*, a^*, b^* values of tea soup were significantly correlated with the scores of color evaluation (P<0.01), and the correlation coefficients were −0.93, 0.97, 0.93, respectively. The L^*, a^*, b^* values of leaf bottom were extremely significantly correlated with the scores of leaf base(P<0.01), and the correlation coefficients were −0.96, 0.97, 0.98, respectively . The L^* value of dry tea, soup color and leaf base was significantly negatively correlated with tea pigment content (P<0.01), and the a^* and b^* values were significantly positively correlated with tea pigment content(P<0.01). The L^* values of dry tea, soup color and leaf base were significantly positively correlated with chlorophyll content(P<0.01), while the a^* and b^* values were significantly negatively correlated with chlorophyll content(P<0.01). The correlation between sensory quality and L^*, a^*, b^* value and pigment of Mengding yellow bud was as follows: It was significantly negatively correlated with L^* value of dry tea, L^* value of soup color, L^* value of leaf base, chlorophyll a, chlorophyll b content (P<0.01), and significantly or significantly positively correlated with a^*b^* value of dry tea, a^*b^* value of soup color, a^*b^* value of leaf base and tea pigment content (P<0.05, P<0.01), except a^* value of dry tea, The correlation coefficients were all above 0.80. The results showed that the lab value measurement method could provide a theoretical basis for the study of the correlation between the color and quality of yellow tea.