海拔与树龄对五峰县茶叶生化成分的影响

Effects of altitude and tree age on the biochemical composition of tea leaves in Wufeng County

中文关键词:  茶叶  海拔  树龄  生化成分  酚氨比  相关性分析  主成分分析

英文关键词:tea leaves  altitude  tree age  biochemical components  ratio of polyphenols and amino acids  correlation analysis  principal component analysis

中文摘要:

      目的 探究海拔、树龄对湖北五峰县夏季茶树鲜叶中主要生化成分的影响。方法 以湖北五峰县海拔217~934 m之间采集的14份茶树一芽二叶鲜叶样本为研究对象, 对其茶多酚、游离氨基酸、咖啡因以及部分儿茶素单体含量进行测定, 并结合相关性分析和主成分分析来分析其变化规律。结果 茶多酚含量在海拔217~820 m范围内随海拔上升而升高, 树龄10年时含量最低; 咖啡因含量与海拔呈极显著正相关, 与树龄无显著相关性; 游离氨基酸含量在海拔610 m处达到最大值; 酚氨比结果显示, 树龄小于15年且海拔610 m以下的茶叶可能更适合制作绿茶, 710 m以上的可能更适合制作发酵茶; 主成分分析结果显示, 提取出前2个主成分, 累计方差贡献率达66.21%, 可以将14份茶树样本以500 m海拔为界限大致分为两类, 且500 m海拔以上的茶树鲜叶中表儿茶素没食子酸酯等儿茶素类物质的含量更高。结论 不同海拔和树龄的茶叶各生化成分之间有不同程度的差异, 研究不同条件下茶叶成分含量为五峰县夏季茶树鲜叶的利用和加工提供了一定的数据支持和理论依据。

英文摘要:

      Objective To study the effects of altitude and tree age on the major biochemical components in fresh summer tea leaves from Wufeng County, Hubei Province. Methods Fourteen samples of one bud and two leaves were collected from tea plants within the altitude range of 217 to 934 meters in Wufeng County. The content of tea polyphenols, free amino acids, caffeine, and selected catechin monomers was determined. Correlation analysis and principal component analysis were conducted to analyze the patterns of variation. Results The content of tea polyphenols was found to increase with altitude within the range of 217 to 820 meters, and the lowest content was observed in 10-year-old plants. The content of caffeine exhibited a significant positive correlation with altitude, while no significant correlation was observed with tree age. The content of free amino acids reached its maximum at an altitude of 610 meters. The ratio of polyphenols and amino acids results showed that tea leaves from tea trees younger than 15 years and below 610 meters in altitude might be more suitable for producing green tea, while those above 710 meters might be more suitable for fermented tea production; the results of principal component analysis showed that the first 2 principal components were extracted, with a cumulative variance contribution rate of 66.21%. The 14 tea tree samples could be roughly divided into 2 categories based on an altitude of 500 meters, and the content of epicatechin, gallate, and other catechin substances in fresh tea leaves above 500 meters was higher. Conclusion Tea leaves from different altitudes and tree ages exhibit varying degrees of differences in biochemical components. Studying the component content of tea leaves under different conditions provides certain data support and a theoretical basis for the utilization and processing of fresh tea leaves in the Wufeng County during the summer.