Triacylglycerols profile and principal component analysis as a chemometric tool to identify wild edible mushroom genera

The Northeast of Portugal is among the European regions with high divers ity of wild mushrooms, some with recognized gastronomic value. Due to the high resemblance among mushroom species belonging to the same genus, finding a distinctive chemometric marker to identify mushroom species is a mandatory task. The lipidic fraction of a natural product has a characteristic pattern of triaeylglyccrol (TAG), comprising specific information due to the genetic control of the stereospecific distribution of fatty acids (FA) on the glycerol molecule, which is typical for each species. Principal component analysis (PCA) was previously applied to classify mushroom samples according to their fatty acids profile.121 However, despite TAG profile was used before to assess the authenticity of oils,l31 it was not used as taxonomical marker. Accordingly, TAG profile was evaluated in 30 wild mushroom species and the results were classified by PCA to identify their discriminant ability. TAG profiles obtained by high performance liquid chromatography coupled to an evaporative light scattering detector showed significant differences among species. The PCA biplot (1) showed that TAG profiles recorded for different mushroom genera may be used as an effective differentiating tool, especially when lowering the taxonomical rank, indicating that TAG profile is most related with the lowest ranks. Ln conclusion, this chemometric approach might be used as a practical tool to identify mushroom species.

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