Research on the Effect of Pigments Rate on Quality and Quantity of Secondary Metabolites in Camellia sinensis L. in 13 Experimental Clones and Comparison in Two Times of Spring and Summer

Abstract

The present study was conducted in 2009 in order to investigate the effects of chlorophyll and carotenoid on determining the quality and quantity of dry tea that was obtained from the selective tea clones and was available in research bases supervised by the National Tea Research Center. To carry out the experiment, random blocks were selected and 13 treatments with 3 repetitions were applied twice (once in the spring and another in the summer). Samples were transferred to the laboratories of the national tea research center in order to measure chlorophyll and carotenoid amounts and qualitative and quantitative characteristics such as caffeine, tannin, Theaflavin (TF), Thearobigin (TR), transparency, function, and total colour. Assessing the amount of chlorophyll and carotenoid was carried out by extracting green tea leaves with methanol and reading it with spectrophotometer; wavelengths of 666 nm, 653 nm, and 470 nm were respectively applied for chlorophyll a, chlorophyll b, and carotenoid. Data analysis was conducted using SPSS and MSTAT-C. The results of variance analysis showed that there was a significant relation between genotypes and Isolation time. They also indicated that genotype and sampling time had mutual effect on each other. Moreover, mean comparison was conducted through Duncan and Sheffe method, the results of which showed that genotype means place in different groups based on different features. Also, assessing correlation of features indicated that pigments rate had a negative correlation with quality factors such as Theaflavin (polyphenol), Thearobigin (Alkaloid), and tannin (polyphenol). It was also concluded that, pigments like chlorophyll and carotenoid had a significant positive relation with tea quality. According to the results of the study, it seems that colon 100 with higher amount of product, lower rate of chlorophyll and carotenoid pigments, and more polyphenols and alkaloids had better performance.