The Study Of Mushrooms By Two-dimensional Correlation Infrared Spectroscopy

There are many species of wild growing mushrooms and the shape of some mushrooms are similar, it is not easy to identify them by morphological characters. Mushrooms are usually sliced and dried for stoage; the morphological featues are disappeared after desiccation. In this dissertation, Fourier transform infrared(FTIR) spectroscopy combined with two-dimensional correlation infrared spectroscopy and multivariate statistical analysis were used to identify and classify mushrooms.The results showed that the FTIR spectra of Russula and Lactarius mushrooms were similar and mainly composed of the absorption bands of protein and polysaccharides. Obvious differences were observed in the second derivative spectra in the range of 1800~1400 cm-1 and 1200~800 cm-1. In the two-dimensional correlation infrared spectra, there were three auto-peaks in the Lactarius, but four in the Russula in the range of 1690~1420 cm-1. In addition, the peak number, position, intensity of auto-peak and cross peak were different in the range of 1110~920 cm-1.Fourier transform infrared spectroscopy, two-dimensional correlation infrared spectroscopy and principal component analysis(PCA) were used to discriminate 7 species of Boletus mushrooms. The significant differences in the position, intensity of auto-peak and cross peak were observed in the two-dimensional correlation infrared spectra in the range of 1680~1300 cm-1 and 1150~920 cm-1. The samples were distinguished with accuracy of 100% by principal component analysis.Fourier Transform Infrared spectroscopy, correlation analysis, second derivative infrared spectroscopy and two-dimensional correlation infrared spectroscopy were used to discriminate 13 species of wild growing mushrooms. The correlation analysis results show that the minimum correlation coefficient is 0.779 and the maximum is 0.960. There were obvious differences in the second derivative infrared spectra in the range of 1700~1400 cm-1 and 1400~800 cm-1. The number, position, intensity of auto-peak and cross peak were significant different in two-dimensional correlation infrared spetra in the range of 920~1230 cm-1.It is demonstrated that Fourier Transform Infrared spectroscopy combined with multivariate statistical analysis and two-dimensional correlation infrared spectroscopy is an effective method to discriminate different wild growing mushrooms.