基于矿物元素指纹图谱技术的武夷岩茶产地溯源研究

    Origin Traceability of Wuyi Rock Tea Based on Mineral Element Fingerprinting

    • 摘要: 武夷岩茶由于外形、工艺的一致性,无法通过外观特征来识别其产地,茶叶中元素组成因产地环境不同而有所差异,形成茶叶产地特有的元素指纹。通过测定武夷岩茶不同产区的多种元素含量,借助化学计量统计方法建立产地判别模型,为武夷岩茶的产地判别提供技术参考。从武夷岩茶3个主要产区采集茶青样品共55件,采用电感耦合等离子体发射光谱法(ICP-OES)和电感耦合等离子体质谱法(ICP-MS)测定矿物元素含量,对数据进行主成分分析,同时采用正交偏最小二乘法判别(OPLS-DA)和Fisher线性判别((FLDA)2种判别方法对武夷岩茶进行产区判别。结果表明:武夷岩茶3个主产区茶叶样品中元素表现出不同的特征,对样品中元素的含量进行巴特利特球形检验,得出取样适切性量数( KaiserMeyer-Olkin,KMO)值为0.650,KMO>0.5说明分组聚类效果较好。通过主成分分析,成功提取了5个主成分,其特征值均超过1,且累计方差贡献率为71.560%。交偏最小二乘法判别模型累积解释能力参数R2X=0.652,(R2Y)=0.752,预测能力参数Q2为 0.590,均>0.5。Fisher线性判别模型对模型构建样本回代验证的正确判别率和交叉验证率均在90.9%以上。2种模型均能实现对3种不同产区采集的茶青样品进行准确判别。研究认为通过3个不同产区采集的武夷岩茶样品中矿物元素指纹分析结合化学计量统计方法,可以有效其进行产地判别,为武夷岩茶原产地保护提供了鉴别理论基础。

       

      Abstract: The indistinguishable appearance and processing of Wuyi Rock Tea prevent origin identification by visual traits, whereas terroir-driven variations in elemental composition generate geographically specific fingerprints. In this study, the contents of multiple elements in Wuyi rock tea from different producing regions were determined, and a discriminant model for origin identification was established using chemometric statistical methods.A total of 55 tea leaf samples were collected from three major producing regions of Wuyi rock tea. The mineral element contents were measured using inductively coupled plasma optical emission spectrometry(ICP-OES)and inductively coupled plasma mass spectrometry(ICP-MS). Principal component analysis(PCA)was performed on the data, successfully extracting five principal components with eigenvalues all greater than 1, and the cumulative variance contribution rate reached 71.560%. Additionally, two discriminant methods orthogonal partial least squares-discriminant analysis(OPLS-DA)and Fisher linear discriminant analysis(FLDA)were employed for origin discrimination of Wuyi rock tea.The results showed that the OPLS-DA model had cumulative explanation ability parameters(R2X = 0.652, R2Y = 0.752)and a predictive ability parameter(Q2 = 0.590), all exceeding 0.5. The FLDA model achieved correct discrimination rates of over 90.9% for both model-building samples and cross-validation. Both models accurately discriminated tea leaf samples from the three different producing regions.This study demonstrates that the mineral elemental fingerprints of Wuyi rock tea samples from different regions, combined with chemometric statistical methods, can effectively determine their origin, providing a theoretical basis for the geographical indication protection of Wuyi rock tea.

       

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