Study On The Influence Factors And Causes On Thearubigins Quantity Of Black Tea

Black tea,which originated in China,is one of the six major teas.The basic procedure is withering——rolling——fermentation——drying,the crucial step is fermentation.During fermentation,polyphenols which mainly consisted by catechins are changed to the tea pigments,various enzymes are the chief influence factor.Thearubigins?TRs?,one of the main components of tea pigment,are positive correlated with the quality of black tea,and it also has many healthy functions.In this paper,we will study and discuss the varieties,fermentation methods,whole process and storage methods.The results showed that even proceed by same method,different varieties turned out the different quantities of TRs.Among all the 22 varieties of black tea,the Hongyan-3,Huangye narcissus,Yunnan big leaf had the top quantity of TRs.Big leaf species had better qualities than the small leaf species.The artificial breeding species always had high quantities of amino acid and aqueous substance.Preference strains have high ratio of TRs and theabrwonins?TBs?.Big leaf Qilan-10 had the high quantities of theaflavins?TFs?and TRs.Preference-5,preference-14 and Yinghong-9 fermented 4 hours under 25?and relative humidity of 95%had the highest quantities of TRs.Big leaf qilan-10fermented 6 hours under the same condition had the highest quantity of TRs.The quantities of TRs were correlated with the temperature and fermentation time,but not obviously correlated with the humidity.We also calculated the regression equation,which had a high fitting degree.During the fermentation of black tea,the TRs reached the summit in the 5^th hour.The TFs reached the summit in the 3^th hour.The generation speed of TBs would slow down but never reduce.The activities of PPO and POD increased slowly before fermentation and decreased fast during fermentation.The activities of PPO and POD were correlated with the variation of TFs,TRs and tea pigments,but were not obviously correlated with the variation of TBs.So we inferred that the TBs may be produced by many enzymes or even nonenzymatic way.Cold storage was the best way to store black tea,followed by shade-seal,seal only.The worst way to store black tea is shade without seal.Correlation analysis showed that cold storage was significantly and positively correlated with the tea quality,non-seal way was significantly and negatively correlated with the tea quality,shade way was not obviously correlated with the quality.In all the method the TFs and TRs decreased with time,the TBs increased in most conditions.Generally speaking,if we want the high quantity of TRs,we should select proper species,ferment at a low temperature and a high humidity,fermentation time should not be too long.Cold storage is the best way to maintain the quality of black tea.