Metabolite, volatile and antioxidant profiles of black garlic stored in different packaging materials

Abstract

This study examined the levels of metabolites, volatile compounds and antioxidant activity of black garlic stored in polyethylene terephthalate bottles (PETB), Kraft paper bags (KPB) and aluminum-laminated polyethylene bags (ALPB) at 4 and 20 °C for 90 days. A total of 27 water-soluble and 96 volatile compounds were identified using NMR and GC-MS. Black garlic packaged with ALPB was markedly different from that packaged with PETB and KPB. ALPB decreased sulfur compounds and increased organic acids, heterocyclic compounds and glucose. The latter are the primary constituents of the roasted and sweet aromas of the garlic. In contrast, sucrose levels were greater for the PETB and KPB storage groups. The antioxidant activity of black garlic decreased in the order of ALPB, KPB and PETB at the same temperature. In general, storage at 20 °C promoted enzymatic hydrolysis and the Maillard reaction while storage at 4 °C maintained antioxidant activity.