Research On The Difference Of Characteristic Components Of Tea Flowers In Different Regions Of Yunnan Province

Tea flower is an important reproductive organ of Camellia sinensis.It is rich in biochemical active components and has the functions of anti-oxidation,lowering blood fat,lowering blood sugar,anti-tumor,whitening and so on.In order to better exploit and utilize tea flower resources in Yunnan province,this paper selected 30 tea flower samples from Xishuangbanna,Pu ’er and Lincang of Yunnan Province.Liquid chromatography and multivariate statistics were used to determine and analyze the characteristic components in the samples.By discussing the content and composition of tea flower samples in different flowering stages,different parts and different regions,analyzing the characteristic components of tea flower samples in different regions,selecting total flavonoids as representative substances for research,studying the influence of extraction technology on total flavonoids content,and analyzing the differences of flavonols and glycosides in tea flower on this basis.The purpose is to provide some reference data for the development and utilization of tea flower resources.The main research contents and results are as follows:1.There are certain rules in the content of main biochemical components of tea flower samples of different varieties at different flowering stages.With the increase of flower maturity,the content of water extract and soluble sugar increased,showing a very significant positive correlation(P<0.01).The contents of tea polyphenols,total flavonoids,gallic acid and caffeine decreased,and the tea flower maturity was significantly negatively correlated with the contents of tea polyphenols,total flavonoids and gallic acid(P<0.01),and significantly negatively correlated with caffeine(P<0.05).Pistil is not only the key component of the reproductive development of tea tree,but also the content of water extract,tea polyphenols and total flavonoids is significantly higher than that of stamen,petal,sepal and whole flower.The content of soluble sugar in stamen,pistil and petal was higher than that in sepal(6.69%),which was an important part of soluble sugar storage in tea flower.The contents of gallic acid and caffeine in sepals were higher in other parts.2.There are regional differences in different tea flower samples under different reproduction modes.The contents of water extract and soluble sugar in Lincang were higher than those in other regions,while the total flavonoid content in Xishuangbanna was higher.The soluble sugar content of tea flowers in Lincang region was much higher than that in Pu’er region.Partial least squares(OPLS-DA)analysis showed that soluble sugar and catechin components were important indicators to distinguish clonal samples from different regions.Total flavonoids,soluble sugar,soluble protein,catechin(C),amino acid and epigallocatechin gallate(EGCG)could be used as the characteristic substances to distinguish three regions in tea flowers of sexual varieties.In addition,the contents of tea polyphenols,total flavonoids and soluble protein of Yunkang No.10 tea flower in different regions decreased with the increase of altitude.3.The effects of solid-liquid ratio,ethanol concentration,extraction temperature and extraction time on total flavonoids extraction of tea flower were explored,and the optimal process parameters were obtained by single-factor experiment combined with response surface optimization: solid-liquid ratio of 1:60g/m L,ethanol concentration of 50%,extraction temperature of 73℃ and extraction time of 30 min.The regression model fitted well and predicted and analyzed the results well.The influence of various factors on the yield of flavonoids was as follows: extraction temperature > ethanol concentration >extraction time > solid-liquid ratio.In addition,solid-liquid ratio and extraction temperature had the most significant effects on the extraction of flavonoids from tea flowers.4.The high performance liquid chromatography was used to determine eight varieties flavonols and their glycosides in the samples.It was found that the content of citipine was the highest in tea flowers,while the content of quercetin,myricetin and kaonetin were all low.The content of axaxolin in You Xuan No.3 tea flower reached 4.488mg/g,which was significantly higher than other samples.Principal component analysis showed that the comprehensive score in sample of sexual variety was the highest in Xiao Huzhai,and Yunkang No.10 tea flower 3 of clonal variety was the highest.In cluster analysis,sanetin and rutin were the main components to distinguish tea flowers of sexual varieties in different regions.The contents of myricetin and quercetin in Lincang were higher in Yunkang No.10 tea flower 3 and Yunkang No.10 tea flower 4.The heat map showed that myricetin and quercetin made major contributions to the differentiation of tea flowers of clonal varieties in different regions.