Metabolomic discrimination of different grades of pine-mushroom (Tricholoma matsutake Sing.) using 1H NMR spectrometry and multivariate data analysis

Metabolomic analysis of raw and cooked pine-mushrooms (Tricholoma matsutake Sing.) of different grades was performed using 1H nuclear magnetic resonance (NMR) spectrometry and principal component analysis (PCA). PCA of the 1H NMR spectra of aqueous fractions allowed different grades of raw pine-mushroom to be discriminated by a combination of principal component (PC) 1 and PC 2, which accounted cumulatively for 94.1% of the variation in all variables. The major peaks in the 1H NMR spectra that contributed to discrimination of raw mushrooms were assigned to choline, trehalose, threonine, leucine/isoleucine, succinic acid, alanine, and fumaric acid. The combination of PC 1 (70.8%) and PC 3 (7.5%) allowed different grades of cooked pine-mushroom to be discriminated, and the major peaks in the 1H NMR spectra that contributed to discrimination of cooked mushrooms were assigned to succinic acid, trehalose, and fumaric acid. This metabolomic analysis-based method allows different grades of pine-mushroom to be distinguished without any prepurification.