该研究采用一芽三四叶的鲜叶原料，比较了信阳绿茶、信阳红茶和3个不同做青程度的信阳茶的品质及其抗氧化活性，以期为江北茶区小叶种茶树品种的鲜叶进一步开发利用提供理论依据。通过分光光度计、液相色谱和气相色谱-质谱联用仪检测5种茶主要生化成分和挥发性成分，利用1,1-二苯基-2-三硝基苯肼（1,1-Diphenyl-2-Picrylhydrazyl，DPPH）法检测此5种茶的抗氧化活性，最后进行感官审评。结果发现：不同做青程度的信阳茶中所含主要成分的含量及组成存在差异，随着做青程度加深，茶多酚由21.17%降到18.90%（P<0.05），氨基酸由3.43%增加到3.73%（P<0.05），黄酮由5.63 mg/g增加到6.55 mg/g（P<0.05），香气成分呈递增的趋势，尤其单帖类物质增加明显，如β-蒎烯由0.13 μg/g增加到0.37 μg/g、E-β-罗勒烯0.05 μg/g增加到0.15 μg/g（P<0.05）。感官审评发现，轻度做青处理所制的茶叶品质相对较优。通过计算不同做青处理所制茶叶清除DPPH自由基半抑制浓度IC50值（Half Maximal Inhibitory Concentration，IC50），发现随着做青程度加深，IC50值在增大，1/IC50值与茶多酚含量呈极显著正相关（P<0.01），与氨基酸和黄酮含量呈极显著负相关（P<0.01），与19种挥发性成分呈显著负相关（P<0.05），说明适当的做青工艺可以改善一芽三四叶所制信阳绿茶的品质。

The quality and antioxidant activity of Xinyang green tea, Xinyang black tea, and Xinyang teas with different degrees of tossing were compared using the fresh leaf raw materials (one bud and three leaves or four leaves). This provides a theoretical basis for the further development and utilization of the fresh leaves of small-leaf tea varieties in the Jiangbei tea region. The main biochemical and volatile components of the five teas were examined by spectrophotometry, liquid chromatography and GC-MS. Their antioxidant activities were evaluated by the DPPH method, followed by sensory evaluation. The results showed that the contents and composition of the main components in the Xinyang teas with different degrees of tossing differed. As the degree of tossing increased, the content of tea polyphenols decreased from 21.17% to 18.90% (P<0.05), the content of amino acids increased from 3.43% to 3.73% (P<0.05), and the content of flavonoids increased from 5.63 mg/g to 6.55 mg/g (P<0.05). The aroma components showed a steady increase trend, in particular, the contents of monoterpenes increased significantly (P<0.05) e.g. β-pinene increased from 0.13 μg/g to 0.37 μg/g, E-β-basilene increased from 0.05 μg/g to 0.15 μg/g. Sensory evaluation revealed that the quality of tea subjected to light tossing was better . The calculations of the IC50 values of DPPH radical scavenging revealed that with the rise of the degree of tossing, the IC50 value increased. The 1/IC50 value was significantly and positively correlated with the content of tea polyphenols (P<0.01). The 1/IC50 value was significantly and negatively correlated with the contents of amino acids and flavonoids (P<0.01), and significantly and negatively correlated with the contents of 19 volatile components (P<0.05). These results indicate that the quality of the Xinyang green tea made from one bud and three or four leaves can be improved by a proper tossing process.

横向豫新茶研制与开发项目（30801981）；河南农业大学教改项目（2021XJGX101）；社会服务科技特派员项目（30802540）