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.