Combining FTIR-ATR and OPLS-DA methods for magic mushrooms discrimination

Magic mushrooms are naturally occurring fungi that are considered hallucinogenic drugs because they contain psilocybin and psilocin. These substances are controlled in almost every country in the world, so the use, possession, cultivation, and sale of magic mushrooms are prohibited in whole or in part. Despite this, the abuse of magic mushrooms continues and can put at risk the life of the consumer and society in general if the consumer behaves in an unsafe manner. The number of mushroom species is very high, making it difficult to correctly identify them based only on physical and morphological characteristics. Therefore, there is a need to develop non-destructive mushrooms analysis methods that have less response time and higher discrimination ability. The present work used Attenuated Total Reflectance Fourier Transform Infrared (FTIR-ATR) Spectroscopy to study 64 mushroom samples from different genera including hallucinogenic, edible, and toxic species. In addition, this study used Orthogonal Partial Least Squares - Discriminant Analysis (OPLS-DA), using SIMCA chemometric software to analyse the obtained infrared (IR) spectra. The main molecular vibrations of the components of the fungus were successfully identified by IR spectroscopy. Although the specific bands corresponding to psilocybin or psilocin could not be assigned in the spectra, the regression method was able to discriminate the various species. Hallucinogenic mushrooms were well separated from other species, allowing the method to be used as an initial screening technique to determine whether or not the seized mushrooms are of forensic interest