Analysis On The Quality Formation Of Tea Flowers Beverage From Different Varieties

The components of flowers of tea plant[Camellia sinensis（L.）O.Kuntze]determine the qualities of tea flowers beverage.At present,many studies have detected the components of tea flowers and found that it contains tea polyphenols,amino acids and other substances which are beneficial to human body,and it has a wide utilization value.Although some scholars have explored the components of tea flowers in combination with transcriptome data,the whole regulatory network of that is still unclear.In addition,there are few studies on the quality identification of tea flowers beverage made from different varieties of tea flowers by using different processing techniques.In this study,the main components of three varieties of tea flowers,’Baiye 1’（BY）,’Huangjinya’（HJY）,and’Suchazao’（SCZ）,at the hard bud stage（S1）,the white bud stage（S2）and the full blooming stage（S3）,were measured.The dynamic changes of physiological indicators during the whole development process of tea flowers were basically grasped through the differences analysis on different flowering stages and different varieties.The transcriptome data was further analyzed to explore the biosynthetic pathways of the components and identify related differential genes to study the relationship between the differential genes and the formation of components.In addtion,the sensory qualities and components of tea flowers beverage made by different processing techniques（drying,fixing+drying）were analyzed to provide reference value for consumers to select tea flowers beverage.The main findings are as follows:（1）This study found that the contents of the main components of tea flowers from three varieties were all highest at the hard bud stage,which gradually decreased with the degree of flower development.Only the content of theanine reached the highest level at the white bud stage and then also decreased with the development of tea flowers.The free amino acids with higher contents of tea flowers from three varieties at different flowering stages contained Theanine（THEA）,Proline（Pro）,Arginine（Arg）,Glutamic Acid（Glu）,Glutamine（Glu NH₂）,Alanine（Asp NH₂）,Aspartic Acid（Asp）,Serine（Ser）,Phenylalanine（Phe）,Alanine（Ala）,Histidine（His）and so on.（2）The biosynthetic regulatory network of the main components in tea flowers was preliminarily constructed by analyzing transcriptome data.There were 144 differential genes screened out.The expressions and possible interaction effects of these genes during the development of tea flowers were analyzed.And 20 differential genes related to the biosynthesis of the components were randomly selected to be verified by qRT-PCR.The results showed that these differential genes might regulate the content of the components of tea flowers and provide a molecular mechanism for the synthesis of the components,which was expected to be applied to regulate the quality of tea flowers in the future.（3）The sensory evaluation and main components determination of tea flowers beverage made through different processes were carried out to explore the effects of different processing techniques on the quality of tea flowers beverage.The results showed that under different processes,all the sensory indicators of tea flowers beverage made from flowers at the white bud stage were more excellent.Therefore,high-quality varieties of tea flowers at the white bud stage should be preferentially selected to make tea flowers beverage.The moisture content and water extract content of tea flowers beverage made by different processing techniques were highest at the hard bud stage,and then gradually decreased with the development of flowers.The water extract content of tea flowers beverage made by drying process was generally higher.The ratio of polyphenols and amino acids of the tea flowers beverage gradually increased with the development of flowers under the drying process and decreased under the fixing+drying process.In conclusion,the drying process is more suitable for making tea flowers beverage.