对西湖龙井进行原产地精确鉴定是规范市场, 打击假冒伪劣的迫切需求。 文章利用近红外技术对西湖龙井的真伪鉴定进行了研究, 提出了一种模型以进行西湖龙井鉴别的新方法。 结果表明, 利用西湖龙井茶和其他地区以龙井加工工艺制成的扁形茶全区域的近红外原始光谱, 分别对其进行赋值, 采用PLS法建立了西湖龙井的预测模型(主成分数为15), 通过预测值和西湖龙井的临界值进行比对实现了对西湖龙井的真伪的准确鉴定。 对70份定标样品和24份外部验证未知样品鉴定结果的准确率都达到了100%, 证明利用定量分析的PLS法建立的模型能有效准确地进行西湖龙井的真伪鉴定。

Protection of geographical indication for Xihu longjing tea was necessary and an accurate method of identification of Xihu longjing tea ought to be developed to prevent Xihu longjing tea from being faked and protect the trade mark of Xihu longjing tea. Identification of Xihu longjing tea with near-infrared spectrum was researched and a new method for identification of Xihu longjing tea by a quantitative model was developed. A new variance was first defined for Xihu longjing tea and other flat-shaped tea. And then the near-infrared spectrum without preprocess of tea was analyzed and partial least squares (PLS)was most suitably used to build the model (The number of PLS factors in this model is 9)for quantitative prediction. Compared with the critical numeral value, the result predicted by the PLS model was used to identify true Xihu longjing tea. The model was used to predict for 70 known samples which were used to build the quantitative model and 24 unknown samples. The recognition rate of 100% was achieved. So it is proved that the quantitative model by PLS was reliable and accurate to identify real Xihu longjing tea.