利用傅里叶变换红外(FTIR)光谱结合主成份分析（PCA）和系统聚类分析（HCA）技术对不同品种辣椒进行鉴别研究。测试了5种辣椒共50个样品的红外光谱，结果表明，5个不同品种辣椒的红外光谱相似，但在1800～800 cm-1范围内红外光谱的峰位、峰形及吸收强度有一些微小差异。对原始光谱作二阶导数处理，发现在该范围内5种辣椒的二阶导数光谱差异明显，利用该范围二阶导数光谱数据对5个品种50个样品进行聚类和主成分分析。聚类分析正确率为100%,主成分分析正确率达98%，能把5个品种的辣椒分开。研究结果表明：傅里叶变换红外光谱技术结合统计分析的方法可以把不同品种的辣椒区分开。

Fourier transform infrared spectroscopy (FTIR) combined with principal component analysis (PCA) and hierarchical cluster analysis (HCA) is used to study different kinds of capsicum frutescens L.. FTIR spectra of 50 samples are obtained from five species of capsicum frutescens L.. The results show that the infrared spectra of capsicum frutescens L. are similar, but tiny differences in wave-numbers and absorption intensities of peaks are observed in the range of 1800~800 cm-1. PCA and HCA are performed on the second derivative infrared spectra in this range. FTIR spectroscopy is found to be efficient in classification of capsicum frutescens L.. 50 samples are well divided into five groups and about 100% classification accuracy for HCA, about 98% accuracy for PCA are yielded. It is proved that FTIR combined with statistical analysis can be used to discriminate capsicum frutescens L..