辣椒的傅里叶变换红外光谱研究

[目的]利用傅里叶变换红外（FTIR）光谱结合主成分分析（PCA）和系统聚类分析（HCA）技术对不同品种辣椒（Capsicum frutescens L）进行鉴别研究.[方法]测试了5种辣椒50个辣椒的红外光谱.[结果]5个不同品种辣椒的红外图谱相似,但在1 800 ～ 800 cm-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光谱处理,发现在1 800～ 800 cm-1范围内5种辣椒的二阶导数光谱图差异明显,利用1 800～800 cm-1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.聚类分析其正确率为100％;主成分析前3个主成分的累计贡献率达到94.47％,其正确率达98％,能把5个辣椒品种分开.[结论]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来.

Study of Capsicum frutescens L.by Fourier Transform Infrared Spectroscopy

[ Objective ] Fourier transform infrared （FFIR） spectroscopy combined with principal component analysis （PCA） and hierarchical cluster analysis （HCA） were used to study different kinds of Capsicumfrutescens L. [ Method] FTIR spectra of 50 Capsicumfrutescens L. were ob- tained from 5 species of Capsicumfrutescens L.. [ Result] The results showed that the infrared spectra of Capsicumfrutescens L. were similar,but tiny differences in wave-numbers and absorption intensities of peaks were observed in the range of 1800-800cm-1. Derivative spectra of b＇TIR can obviously enhance the spectral resolution and amplify small differences. PCA and HCA were performed on the second derivative infrared spectra in this range of 50 samples. 50 samples according to five different varieties were well divided into five groups, Hierarchical cluster analysis provides about 100% of correct classification. The first three principal components have a cumulative contribution rate of 94.47% ,and yield classification accuracies of 98%. [ Conclusion] It is proved that F＇FIR spectroscopy combined with statistical analysis could be used to discriminate Capsicum frutescens L..