[Discrimination of Lactarius and Russula Mushrooms with FTIR and Two-Dimensional Correlation Infrared Spectroscopy].

Tri-step infrared spectroscopy method of Fourier transform infrared spectroscopy, second derivative infrared spectroscopy and two-dimensional correlation infrared spectroscopy was firstly used to discriminate six species of mushrooms belonging to the genus Lactarius and Russula. The absorption bands of the original spectrum were very similar, which were composed by protein and polysaccharides, but tiny differences were observed at the position, shape and absorption intensities of peaks. Second derivative infrared spectroscopy technology was applied to study 6 species of the samples, there were obvious differences in the range of 1 800～1 400 and 1 200～800 cm-1. Two-dimensional correlation infrared spectroscopy can improve the resolution of spectra. Therefore two-dimensional correlation infrared spectroscopy was used to study 6 kinds of mushrooms. The results showed that there are three auto-peaks in the Lactarius, four in the Russula and significant differences in the number, intensity of auto-peaks and cross peaks were observed in the range of 1 690~1 420 cm-1. In addition, the peaks quantity, position, intensity of auto-peaks and cross peaks were different in the range of 1 110~920 cm-1. It demonstrates that tri-step infrared spectroscopy technology of Fourier transform infrared spectroscopy, second derivative infrared spectroscopy and two-dimensional correlation infrared spectroscopy is a rapid and effective method for discriminating Lactarius and Russula.

[Discrimination of Seven Species of Boletus with Fourier Transform Infrared Spectroscopy].

Fourier transform infrared spectroscopy, two-dimensional correlation infrared spectroscopy and principal component analysis were used to discriminate seven species of boletus belonging to the same genus. The results showed that the absorption bands of original spectra were similar, which were mainly composed of the absorption bands of protein and polysaccharides, but tiny differences were still observed at the position and intensities of peaks. Two-dimensional correlation infrared spectroscopy technology was applied to study the sample. It showed that there are 6 auto-peaks in the Boletus brunneissimus Chiu and Boletus bicolor, 5 auto-peaks in the Boletus speciosus, 4 auto-peaks in the Boletus griseus Forst and Boletus calopus, only 3 in the Boletus edulis and Boletus aereus in the range of 1 680~1 300 cm-1. The significant differences in the position, intensity of auto-peaks and cross peaks were still observed in the range of 1 680~1 300 cm-1. Same significant differences were observed in the range of 1 150~920 cm-1. Principal component analysis was conducted on boletus with second derivative infrared spectra in the range of 1 800~800 cm-1. All the samples were distinguished and the classification accuracy of principal component analysis is up to 100%. It is demonstrated that Fourier transform infrared spectroscopy combined with two-dimensional correlation infrared spectroscopy or principal component analysis is a rapid and effective method for discriminating mushrooms.