Small in size, big on taste: metabolomics analysis of flavor compounds from Philippine garlic

Abstract

Philippine garlic (Allium sativum L.) is arguably known to pack flavor and aroma in smaller bulbs compared to imported varieties saturating the local market. In this study, ethanolic extracts of Philippine garlic cultivars were profiled using ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-QTOF). {gamma}-Glu dipeptides, oligosaccharides and lipids were determined in Philippine garlic cultivars through bioinformatics analysis in GNPS Molecular Networking Platform and fragmentation analysis. Multivariate statistical analysis using XCMS Online showed the abundance of {gamma}-Glu allyl cysteine in Batanes-sourced garlic while {gamma}-Glu propenyl cysteine, {gamma}-Glu methyl cysteine, and alliin are enriched in the Ilocos cultivar. Principal component analysis showed that the {gamma}-Glu dipeptides found in local garlic influenced their distinct separation across PC1 from imported varieties. This presence of high levels of {gamma}-Glu dipeptides and probiotic oligosaccharides may potentially contribute to the superior flavor and nutritional benefits of Philippine garlic.