Metabolomics based on GC-MS combined with chemometrics for geographical discrimination of garlic (Allium sativum L.)

Abstract

Ensuring the geographic origin of products helps protect consumers against fraud and mislabeling. This study investigates the metabolomic profiles of garlic (Allium sativum L.) samples from Brazil and China using gas chromatography-mass spectrometry (GC-MS). Multivariate analysis Partial Least Squares Discriminant Analysis (PLS-DA) and Orthogonal PLS-DA (Ortho PLS-DA) revealed clear metabolic distinctions between the two sample groups with high classification accuracy. Brazilian garlic samples showed higher levels of sulfur compounds, such as allyl propyl sulfide, cysteine sulfonic acid, and S-carboxymethyl-L-cysteine, which contribute to its pungency and potential health benefits. Amino acids L-arginine, L-glutamic acid, and L-cysteine were also significantly increased in garlic from Brazil. In contrast, Chinese garlic exhibited higher intensities of sugars (e.g., D-fructose, D-mannose) and essential amino acids (L-tryptophan, L-valine, and L-leucine). These differences in metabolism are the result of distinct metabolic profiles. GC-MS-based untargeted metabolomic and chemometric analysis were able to differentiate the geographical origin of Brazilian and Chinese garlics and remain valuable to food authentication and quality control. Further studies are needed to confirm the biomarkers for origin verification here stated.