萎凋叶含水量对四川中小叶群体种工夫红茶品质形成的影响

Effect of water content of withered leaves on the quality of Congou black tea processed by Sichuan small and medium leaf group species

中文关键词:  萎凋  含水量  工夫红茶  四川中小叶群体种  品质

英文关键词:withering  water content  Gongou black tea  Sichuan small and medium leaf group species  quality

中文摘要:

      目的 探索萎凋程度对重庆工夫红茶品质形成的影响。方法 以四川中小叶群体种为研究对象, 分析比较了3个萎凋含水量: 处理A(69.59%)、处理B(65.17%)、处理C(59.20%)萎凋叶红茶加工过程中色泽、多酚氧化酶(polyphenylene oxide, PPO)活性变化及对后续揉捻效果、生化成分、工夫红茶成茶品质形成的影响。结果 随着萎凋水分的降低, 萎凋叶L*, b*值呈下降的趋势, a*值呈上升的趋势, 4~6 h时均出现了与总体趋势相反的波动; 加工过程中, 各处理L*, b*值均呈下降的趋势, a*值在发酵前呈增高的趋势, 干燥后值减小。成茶色泽L*a*b*值则均表现为处理A>处理C>处理B。加工过程中PPO活性呈先升后降的趋势, 随萎凋程度的加重, 高峰往后延迟且活性越强, 处理C在发酵环节中活性最高。揉捻环节随着萎凋叶含水量的降低成条率越高, 扁条率越低, 细胞破碎率越高, 处理C效果最好。内含物质随着萎凋叶含水量的减少, 茶多酚先增后减, 氨基酸先减后增, 咖啡碱呈先减后增再减式起伏变化; 水浸出物、可溶性糖差异不明显; 成茶中处理C综合感官品质表现最好。结论 萎凋叶含水量在60%左右时, 有利于发挥四川中小叶群体种品种优势, 加工出的工夫红茶品质良好。

英文摘要:

      Objective To explore the influence of withering degree on the quality formation of Chongqing Congou black tea. Methods Taking middle-leaflet population of Sichuan as the research object, the changes of color and luster, polyphenylene oxide (PPO) activity and the effect on the follow-up twisting effect, biochemical composition and the formation of tea quality of Gongfu black tea were analyzed and compared with 3 withering water contents: treatment A (69.59%), treatment B (65.17%) and treatment C (59.20%) during the processing of withered black tea. Results With the decrease of withering water content, the values of L* and b* of withering leaves showed a downward trend, while the values of a* showed an upward trend, and the fluctuation was opposite to the general trend from 4 h to 6 h. During the processing process, the L* and b* values of each treatment showed a downward trend, the a* value showed an upward trend before fermentation, and the value decreased after drying. The color L*a*b* values of the tea showed treatment A>treatment C>treatment B. PPO activity showed a trend of increase first and then decrease during processing. With the aggravation of withering degree, the peak was delayed and the activity was stronger. Treatment C had the highest activity in the fermentation process. With the decrease of water content in withered leaves, the higher the stripe formation rate was, the lower the flat stripe rate and the higher the cell breakage rate was in the rolling process. Treatment C had the best effect. With the decrease of water content in withered leaves, tea polyphenols increased first and then decreased, amino acids decreased first and then increased, and caffeine decreased first and then increased and then decreased. There was no obvious difference between water extract and soluble sugar. The comprehensive sensory quality of treatment C was the best in the tea. Conclusion When the water content of withered leaves is about 60%, it is beneficial to give full play to the advantages of Sichuan medium and small leaf population varieties, and the processed Gongfu black tea has good quality.