为探究环境湿度和温度对茶叶贮藏品质的影响,以龙井绿茶和工夫红茶为研究对象,通过将其贮藏于室温及4 ℃的高湿区(RH 65%)、中湿区(RH 45%)、干区(RH 25%)共6种贮藏环境中3个月后,分析茶叶的品质变化规律。结果表明,整体上环境湿度越低,茶叶生化成分含量及干茶色泽品质就会越高,其中中湿区部分生化成分含量已显著高于高湿区(P<0.05),且与干区无显著差异(P>0.05);相同湿度环境下,对于龙井绿茶,4 ℃更有利于其生化成分含量和干茶色泽品质的保持,对于工夫红茶,则4 ℃和室温均可;龙井绿茶和工夫红茶的感官品质分别在4 ℃和室温的中湿区最优。综上,4 ℃中湿区和室温中湿区可分别作为绿茶和红茶短期贮藏环境。同时逐步回归结果表明氨基酸、VC、a值及茶黄素可分别作为表征其短期贮藏品质的主要指标。该研究为茶叶贮藏保鲜提供了理论参考。
Longjing green tea and congou black tea were selected as research objects to investigate the effects of ambient temperature and humidity on the storage quality of tea leaves. Samples were stored respectively in six different environments, i.e. high humidity (RH 65 %), average humidity (RH 45 %), low humidity (RH 25 %) respectively at room temperature and at 4 ℃ for 3 months to analyze the pattern of quality changes. Results showed that in general, the lower the ambient humidity, the higher the content of biochemical components and better the color quality of dry tea leaves, among which the level of certain biochemical components in medium humidity environment/ was significantly higher than that in high humidity environment (P<0.05) without major difference from dry environment (P<0.05). For Longjing green tea, 4 ℃ was better for maintaining the level of biochemical components and the color quality given the same humidity condition. For congou black tea, no major difference in storage quality was observed between 4 ℃ and room temperature. For Longjing green tea and cougou black tea, the best sensory quality was obtained under medium humidity environment respectively at 4 ℃ and room temperature. In summary, medium humidity at 4 ℃ and medium humidity at room temperature could be used for short-term storage respectively for Longjing green tea and congou black tea. Meanwhile, results of stepwise regression showed that amino acid, vitamin C, a value and theaflavins could be used as main indicators to characterize their short-term storage quality. This study has provided a theoretical reference for storage and fresh-keeping of tea leaves.
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