Analysis of Taste and Differential Metabolites of Different Ganoderma lucidum Strains Based on Electronic Tongue and Non-targeted Metabolomics

In order to explore the differences of taste and metabolites of different Ganoderma lucidum strains, the fruiting bodies of different Ganoderma lucidum strains were taken as samples, the taste of aqueous extracts of 21 different Ganoderma lucidum strains were determined by electronic tongue. The non-targeted metabonomics techniques of ultra high performance liquid chromatography and mass spectrometry were used. Combined with principal component analysis (PCA) and orthogonal partial least square discriminant analysis (OPLS-DA) and other statistical methods based on the results of taste cluster analysis, three different Ganoderma lucidum strains (GL229, GL219, GL236) were selected for metabolite identification and analysis. The results showed that the response values of sour, umami, bitter and salty taste of water extracts of different Ganoderma lucidum strains were quite different. A total of 6057 metabolites were identified from the water extracts of three different Ganoderma lucidum strains. There were 1282, 1311 and 1966 differential metabolites between GL219 and GL229, GL236 and GL229, GL219 and GL236, respectively. There were 123 differential metabolites among the three control groups, including organic acids and their derivatives, benzene ring compounds, organic oxygen compounds, organic heterocyclic compounds, lipids and lipid compounds. The main differential metabolites were Jamaicamide C, 2-isopropylmalicacid, 1-naphthylamine, tyramine, genipin and so on. The differential metabolites L-glutamine, glutamine, cinchonine, solanidine, phenylacetaldehyde and dehydrocholicacid were flavor substances, which contributed to the taste differences of water extracts of different Ganoderma lucidum strains. This study showed that metabonomics could be used to analyze the compositions differences of Ganoderma lucidum with different taste. Therefore, it could provide a theoretical basis for the material basis of Ganoderma lucidum taste.