Biochemical Characteristics Analysis and Suitability Evaluation of Liannan Daye Tea Germplasm Resources

This study aimed to systematically analyze the biochemical composition of Liannan Daye tea germplasm from Guangdong Province and to evaluate its suitability and quality characteristics for green tea and black tea through sensory evaluation. The findings were intended to provide the scientific support for the breeding of new Liannan Daye varieties, the conservation and utilization of local tea resources, and the development of functional tea products.

A total of 19 representative Liannan Daye tea germplasm resources were selected for biochemical composition analysis. 16 key compounds were quantified, including water extract, tea polyphenols, free amino acids, catechins, and alkaloids. Principal component analysis (PCA) and cluster analysis were employed to systematically evaluate the variability of these components. In addition, sensory evaluation was conducted to assess the quality of green teas and black teas made from each resource.

Significant differences in biochemical composition were observed among the 19 Liannan Daye tea germplasm resources. Variations were especially notable in amino acids, theanine, tea polyphenols, theacrine, and caffeine content. Most resources exhibited high levels of amino acids and theanine but relatively low content of tea polyphenols and catechins. All resources had phenol-to-amino acid ratios below 8.0, indicating good suitability for green tea production. Sensory evaluation showed that green teas made from Liannan Daye exhibited generally high quality in appearance, liquor color, aroma, and taste. In particular, Liannan Daye 16, 29, and 38 demonstrated superior overall quality. For black tea, Liannan Daye 31 and 38 also exhibited excellent performance. Cluster analysis grouped the 19 Liannan Daye tea resources into three distinct clusters and identified eight resources with unique traits, including two high amino acid content, three high theanine content, two high theacrine content, and one low caffeine content.

The Liannan Daye tea germplasm resources exhibited significant diversity in both biochemical composition and sensory quality. Differences in the levels of amino acids, theanine, and theacrine directly affected their suitability for green tea or black tea production. High amino acid, high theanine, and low caffeine resources were more suitable for green tea processing, while high theacrine resources showed potential for the development of functional tea products.