武义有机茶品质和稳定同位素特征及识别

doi:10.16178/j.issn.0528-9017.20230629

摘要/Abstract

摘要：

武义县是我国首个“有机茶之乡”,为挖掘武义有机茶的关键特征指标,本研究分别在早春和晚春时期采集了武义县不同肥料和不同有机栽培年份的茶叶样品,采用化学分析、感官审评和元素分析-稳定同位素比率质谱等技术,对茶叶中的主要化学成分、感官品质以及碳、氮元素和同位素含量(δ¹³C、δ¹⁵N)进行检测。结果表明,相较于使用化肥的茶叶,使用有机肥茶叶中游离氨基酸含量更高、香气和滋味更优、δ¹⁵N含量更高。大部分化学成分和稳定同位素比值均在有机栽培5~10 a的茶叶样品中更高。利用化学成分和碳氮元素组成建立偏最小二乘法判别模型,能够很好地区分有机栽培和常规栽培茶叶。结合变量重要性投影分析,表明δ¹⁵N和茶多酚含量是判别有机茶的关键特征指标。该研究为促进有机茶产业健康发展及市场监管提供了技术支撑和科学依据。

关键词: 有机茶, 品质成分, 稳定同位素, 偏最小二乘法

Abstract:

Wuyi County is the first “Hometown of Organic Tea” in China. In order to explore the key characteristic indicators of Wuyi organic tea, this study collected tea samples from different fertilizers and organic cultivation years in Wuyi County in early and late spring. Chemical analysis, sensory evaluation, and elemental analysis stable isotope ratio mass spectrometry were used to analyze the main chemical components, sensory quality, the content of carbon, nitrogen elements, and isotope(δ¹³C、δ¹⁵N) content of tea. The results showed that compared with the tea treated with chemical fertilizers, tea treated with organic fertilizers had a higher content of free amino acids, better aroma and taste. The content of δ¹⁵N was higher. Most of the chemical composition and stable isotope ratios were higher in tea samples grown organically for 5-10 years. Establishing a partial least squares discriminant model using chemical composition and carbon and nitrogen element composition can effectively distinguish between organic and conventional tea cultivation. Combining variable importance for projection analysis, it indicated that the content of δ¹⁵N and tea polyphenol were key characteristic indicators for distinguishing organic tea. This article provides technical support and scientific basis for promoting the healthy development of the organic tea industry and market regulation.

Key words: organic tea, quality components, stable isotope, partial least squares method

中图分类号:

S571.1

徐欢, 郭祖闯, 刘瑞敏, 邵圣枝, 袁玉伟, 李春霖. 武义有机茶品质和稳定同位素特征及识别[J]. 浙江农业科学, 2024, 65(7): 1687-1694.

XU Huan, GUO Zuchuang, LIU Ruimin, SHAO Shengzhi, YUAN Yuwei, LI Chunlin. Quality and stable isotope characteristics and identification of Wuyi organic tea[J]. Journal of Zhejiang Agricultural Sciences, 2024, 65(7): 1687-1694.

图/表 10

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肥料种类	早春			晚春
肥料种类	水浸出物含量	茶多酚含量	游离氨基酸含量	水浸出物含量	茶多酚含量	游离氨基酸含量
化肥	50.7±0.2	20.3±0.1	4.8±0.0	45.6±0.3	15.2±0.0	2.4±0.2
菜籽饼	50.1±0.3	16.3±0.1	5.2±0.2	48.5±1.3	17.2±0.9	3.1±0.3
商品有机肥	49.5±0.3	18.0±0.1	6.1±0.2	47.2±0.3	15.5±0.5	3.2±0.3

肥料种类	早春			晚春
肥料种类	水浸出物含量	茶多酚含量	游离氨基酸含量	水浸出物含量	茶多酚含量	游离氨基酸含量
化肥	50.7±0.2	20.3±0.1	4.8±0.0	45.6±0.3	15.2±0.0	2.4±0.2
菜籽饼	50.1±0.3	16.3±0.1	5.2±0.2	48.5±1.3	17.2±0.9	3.1±0.3
商品有机肥	49.5±0.3	18.0±0.1	6.1±0.2	47.2±0.3	15.5±0.5	3.2±0.3

肥料种类	外形	汤色	香气	滋味	叶底
化肥	条索紧结,略曲,有毫,略有锋苗,稍带朴,深绿稍偏黄尚润	较嫩绿明亮	较高,略有嫩香	尚醇,微涩(欠鲜爽)	较嫩软,有芽,有嫩茎、摊张,较绿亮
菜籽饼	条索紧实,略曲,带茎梗、朴片,深绿稍偏黄尚润	尚绿亮	较高爽,尚鲜,有嫩香,略有花香	较醇,尚厚,较清鲜	尚嫩,多嫩茎、摊张,尚绿亮
商品有机肥	条索紧结,较壮,显毫,有锋苗,深绿稍偏黄尚润	尚嫩绿(偏黄)明亮	较高,有嫩香,略有花香,略熟闷	醇厚,尚鲜,微熟甜	较细嫩,多芽,较嫩绿亮

肥料种类	外形	汤色	香气	滋味	叶底
化肥	条索紧结,略曲,有毫,略有锋苗,稍带朴,深绿稍偏黄尚润	较嫩绿明亮	较高,略有嫩香	尚醇,微涩(欠鲜爽)	较嫩软,有芽,有嫩茎、摊张,较绿亮
菜籽饼	条索紧实,略曲,带茎梗、朴片,深绿稍偏黄尚润	尚绿亮	较高爽,尚鲜,有嫩香,略有花香	较醇,尚厚,较清鲜	尚嫩,多嫩茎、摊张,尚绿亮
商品有机肥	条索紧结,较壮,显毫,有锋苗,深绿稍偏黄尚润	尚嫩绿(偏黄)明亮	较高,有嫩香,略有花香,略熟闷	醇厚,尚鲜,微熟甜	较细嫩,多芽,较嫩绿亮

肥料种类	早春				晚春
肥料种类	C含量/%	N含量/%	δ¹³C含量/‰	δ¹⁵N含量/‰	C含量/%	N含量/%	δ¹³C含量/‰	δ¹⁵N含量/‰
化肥	47.83±0.31	5.17±0.15	-27.07±0.21	1.10±0.44	47.57±0.21	3.20±0.10	-26.80±0.10	-0.73±0.06
菜籽饼	48.03±0.40	5.87±0.06	-28.37±0.06	2.70±0.10	48.03±0.35	4.27±0.12	-27.57±0.06	4.47±0.15
商品有机肥	47.20±0.10	6.07±0.12	-24.47±0.40	1.87±0.21	48.13±0.23	3.97±0.06	-26.47±0.12	2.30±0.52