Assessment of phenolic profile, allicin content, and inhibitory potential against α-amylase and α-glucosidase on conventional and organic garlic (Allium sativum L.)

Garlic is a rich source of phenolic compounds having a proven positive effect on human health. The objective of this study was to analyze garlic from different origins and evaluate the influence of organic and conventional agronomic practices on concentrations of phenolic compounds and their potential health benefit of soft- and hard-neck garlic cultivars. A total of 30 garlic samples from different parts of the world analyzed on phenolic compounds including caffeic, ferulic, p-coumaric, gallic acids, quercetin, and allicin were identified. Moreover, some potential inhibitors against key enzymes relating to diabetes including & alpha;-amylase and & alpha;-glucose were determined. Caffeic acid, ranging between 20.57 and 0.80 mg/kg DM, was the main phenolic acid, found in all tested garlic varieties. The content of phenolic acids, flavonoids, and allicin was significantly higher in organic garlic. The allicin content in organic garlic varied from 4.51 to 26.79 mg/g DM while these compounds in conventional garlic ranged between 2.71 and 19.10 mg/g DM, respectively. A correlation (r = - 0.203 and r = 0.195, p < 0.05) was observed between allicin content and & alpha;-amylase, and & alpha;-glucose inhibition was observed, respectively. Therefore, organic garlic has greater potential health benefits than conventional garlic.