绿茶汤中茶多酚近红外定量分析的光程选择  

Selection of optical path length on nir analysis for tea polyphenols in green tea drinks

作　　者：姜礼义[1] 刘福莉[1] 陈华才[1] 尹军锋[2] 

机构地区：[1]中国计量学院光学与电子科技学院,浙江杭州310018 [2]中国农业科学院茶叶研究所,浙江杭州310008

出　　处：《中国计量学院学报》2009年第2期135-138,共4页Journal of China Jiliang University

基　　金：农业部公益性行业(农业)科研专项子项目(No.nyhyzx07-021-18)

摘　　要：研究了光程对近红外定量分析绿茶汤中茶多酚的影响.以不同光程(1 mm,2 mm,5 mm)的样品池采集50个绿茶汤样品的近红外透射光谱.采用偏最小二乘法(PLS)建立茶汤中茶多酚的定量分析模型,并验证模型的准确度和精密度.结果表明,选择1 mm光程光谱建立的茶多酚定量分析模型最优,模型的校正集相关系数R2和内部交叉验证均方根RMSECV分别为91.08%和0.009 3%;检验集相关系数R2和预测标准差SEP为91.53%和0.008 5%;实际值与预测值配对t检验值为0.224 9,差异不显著.10次重复测量相对标准偏差RSD为0.008 7%,表明方法检测重复性好.The influence of optical path length to tea polyphenols （TP） determination in green tea drinks by near infrared spectroscopy was investigated. NIR transmission spectra of green tea drink samples were collected with different optical path lengths （1 mm, 2mm and 5 mm）. Calibration models were established using partial least square （PLS） regression. Comparison of the determination coefficient （R^2 ） and the standard error of prediction （SEP） of the models with different optical path lengths showed that the models built with spectra collected in 1 mm path length gave the best result. For the 1 mm model, the values of R^2 and RMSECV of the calibration sample set were 91.08% and 0. 009 3%, respectively. The values of R^2 and the standard error of prediction （SEP） of the prediction sample set were 91.53 % and 0.008 5 %, respectively. T-test （t = 0. 224 9 ） between the true values and the prediction values indicated that there was no significant difference between the two set values. The relative standard deviation （RSD= 0.008 7 %） of ten repetitive tests suggested that the method is precise.

关 键 词：光程 近红外透射光谱 绿茶汤 茶多酚 定量分析模型 

分 类 号：TS272.51[农业科学—茶叶生产加工]