为探讨相同遮阴条件下不同采摘季的碾茶品质差异，该研究以春末期、夏初期、夏中期的同等级福鼎大白茶鲜叶为对象，以相同碾茶工艺加工后，开展相关生化成分检测分析。结果表明，随采摘时期的后移碾茶的水浸出物、茶多酚、叶绿素总量、叶绿素b、TDF、IDF及SDF含量、酚氨比及IDF/SDF比值呈显著增加（P<0.05），游离氨基酸总量、Vc含量、叶绿素a/叶绿素b比值呈显著降低（P<0.05）。主成分分析表明，游离氨基酸总量、水浸出物、SDF、叶绿素a、可溶性糖和GCG含量的累积方差贡献率达95.73%，可作为碾茶品质的表征性成分。春末期采摘加工的碾茶N1的可溶性糖含量（3.00%）、游离氨基酸总量（4.40%）、咖啡碱含量（2.57%）、Vc含量（5.25 mg/g）、没食子酸含量（1.10%）、EGCG含量（6.74%）、酯型儿茶素总量（9.02%）和儿茶素总量（10.40%）最高，茶多酚含量（10.94%）、儿茶素苦涩味指数（16.59）、酚氨比（2.49）及IDF/SDF比值（4.84）最低，综合品质最佳。因此春末期加工的碾茶品质最佳，夏初期、夏中期加工的碾茶品质相对较差。该研究可为贵州碾茶和抹茶的生产加工技术及品质提升提供科学的理论依据。

In order to investigate the quality difference of tencha collected in different picking seasons under the same shading conditions, the fresh leaves of the same grade Fuding Dabai tea collected in late spring, early summer and midsummer were used as the objects in this study. Relevant biochemical components were detected and analyzed after the teas being processed by the same tencha process. The results showed that with the picking period being moved to a later time, the contents of water extract, tea polyphenols, total chlorophyll, chlorophyll b, TDF, IDF and SDF, the phenol-ammonia ratio and the IDF/SDF ratio increased significantly (P<0.05), and the total free amino acid content, Vc content and the chlorophyll a/chlorophyll b ratio decreased significantly (P<0.05). Principal component analysis showed that the cumulative variance contribution rate of total free amino acids, water extract, SDF, chlorophyll a, soluble sugar and GCG contents reached 95.73%, which could be used as a characteristic component of the quality of tencha. The soluble sugar content (3.00%), total free amino acid content (4.40%), caffeine content (2.57%), Vc content (5.25 mg/g), gallic acid content (1.10%), EGCG content (6.74%), content of total ester-type catechins (9.02%), and content of total catechins (10.40 %) of the tencha N1 harvested at the end of spring were the highest, whilst the tea’s polyphenol content (10.94 %), catechin bitterness and astringency index (16.59), phenol-ammonia ratio (2.49) and IDF/SDF ratio (4.84) were the lowest, thus, the overall quality was the best. Therefore, the quality of tencha processed in late spring was the best, whilst the quality of tencha processed in early summer or mid-summer was relatively poor. This study can provide a scientific theoretical basis for the production and processing technology and quality improvement of Guizhou tencha and matcha.

国家茶叶产业技术体系项目（CARS-19）；贵州省科技计划项目（黔科合基础[2019]1077；黔科合服企[2020]4016；剑科特派合[2022]10）