不同加工工艺西湖龙井茶品质差异特性分析

为明晰不同加工工艺西湖龙井茶的品质特性差异，采用全机制、一青机制后手工、二青机制后手工、全手工等4种方式加工西湖龙井茶，比较分析感官品质和理化成分含量，并分析色差值与汤色的关系。结果表明，一青机制后手工、二青机制后手工工艺的茶外形优于纯手工工艺的茶叶，一青机制后手工工艺的西湖龙井茶滋味、香气与纯手工工艺的茶叶相当，且优于全机制工艺，即扁形炒制机青锅1次与手工辉锅结合的一青机制后手工工艺有利于提升西湖龙井茶品质；4种方式加工的西湖龙井茶的茶多酚含量、咖啡碱含量、游离氨基酸含量、L值差异不显著（P>0.05），a值、b值差异显著（P<0.05）；一青机制后手工工艺有利于西湖龙井茶EGCG、GCG、谷氨酰胺、茶氨酸等关键风味化学物质的保留。采用一青机制后手工的创新工艺，显著改善了全机制西湖龙井茶滋味和香气品质，与全手工工艺的西湖龙井茶品质相当，可为西湖龙井茶品质提升提供技术支持和理论依据。

Difference Quality Characteristics of Xihu Longjing Tea with Different Processing Technology

In order to clarify the differences of quality characteristics of Xihu Longjing tea with different processing technologies, four processing methods were used to process the Xihu Longjing tea, including the method of processing tea with machines in all processes, the method of handmade processing after one fixation by machine, the method of handmade processing after two fixation by machine, and the method of handmade tea for all processes. The sensory quality and the content of physical and chemical components were compared and analyzed, and the relationship between color difference and soup color was analyzed. The results showed that the shape of the tea made by handmade processing after one fixation by machine and handcraft processing after two fixation by machine was better than that of handmade tea for all processes. The taste and aroma of the Xihu Longjing tea by the handmade processing after one fixation by machine was similar to that of the handmade tea for all processes, and it was better than that of the processing tea with machines in all processes. There were no significant differences in polyphenol content, caffeine content, free amino acid content and L value (P>0.05) among four processing methods, but significant differences in a value and b value (P<0.05). The method of handmade processing after one fixation by machine was conducive to the retention of key flavor chemicals such as EGCG, GCG, glutamine and theanine in Xihu Longjing tea. The taste and aroma quality of the Xihu Longjing tea was significantly improved by the innovative technology of handmade processing after one fixation by machine, which was equivalent to the tea by handmade tea for all processes. It can provide technical support and theoretical basis for the quality improvement of Xihu Longjing tea.