Profiling of organosulfur compounds and amino acids in garlic from different regions of China.

The quality of garlic is mainly attributed to organosulfur compounds that are the secondary metabolites of certain amino acids. Herein, a sensitive and rapid method for the simultaneous determination of 7 organosulfur compounds and 21 amino acids using ultra-high-performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS) was developed. Then the levels of these 28 compounds and allicin in garlic among 242 samples from 6 provinces in China were profiled with multivariate data analysis. The results showed that garlic was rich in organosulfur compounds and could be a good supplement for amino acids. Contents of 29 compounds varied greatly among the provinces. The multivariate data analysis demonstrated two major groups for all samples, indicating that the location has a significant influence on the metabolism of garlic. Besides, the compositional differences of garlic from 6 provinces and correlations for growing conditions and contents of components were also analyzed.