Metabolomic analysis of garlic varieties revealed high cycloalliin content in fresh and black Kinkyou bulbs

Abstract

Garlic has unique aroma and functional components, exhibits anti-platelet aggregation activity, anti-allergic effects of ajoene, and so on, and is indispensable for many tasty dishes. To understand the characteristic metabolites, comprehensive metabolomic analysis of water-soluble components from garlic and black garlic (Kinkyou, Taisou, and Katei lines and Fukuchi White cultivar) was carried out using GC/MS. Kinkyou, which is cultivated as a new line in Kagawa, Japan, was assessed for physiologically important components in comparison with 3 popular garlic types. The loading values of principal component analysis of the characteristics of Kinkyou were mainly attributed to glutamic acid, threonine, cycloalliin, and so on. The amount of cycloalliin as a typical functional component of Kinkyou was determined to be about 327 mg/100 g dry wt. by HPLC analysis (2-fold that of the other 3 garlic). Additionally, the amount of cycloalliin in Kinkyou black garlic after processing was increased to 420 mg/100 g dry wt.