2-Furoylmethyl amino acids as indicators of Maillard reaction during the elaboration of black garlic.

This study reports the formation of 2-furomethyl-amino acids (2-FM-AA) as indicators of Maillard reaction (MR) in black garlic elaboration, followed by the determination of furosine by ion-pair RP-HPLC-UV. The method was assessed for accuracy, repeatability and detection and quantitation limits indicating its adequacy. Traditional procedure of black garlic obtainment and the inclusion of convective drying (CDP) and ohmic heating (OHP) were assayed. For comparison purposes, three commercial black garlic samples were used. Together with furosine (2-FM-lysine), 2-furoylmethyl-γ-aminobutyric acid and 2-FM-arginine were detected. Levels of furosine were higher in CDP (46.6-110.1mg/100g protein) than in OHP (13.7-42.0mg/100g protein) samples, probably due to the most severe processing conditions used in the former. These results highlight the suitability of 2-FM-AA as chemical indicators to monitor the process of black garlic elaboration in order to obtain high quality products.

In vitro and in vivo antioxidant activities of polyphenol extracted from black garlic

Abstract This study investigated the in vitro and in vivo antioxidant activities of polyphenol extracted from black garlic. Black garlic polyphenol (BGP) was extracted from black garlic. The in vitro antioxidant activities of BGP were determined using DPPH·, OH and O2- radical scavenging assays. The in vivo antioxidant activities were determined by detecting the malondialdehyde (MDA) content and superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities in mice. Results showed that, the DPPH· radical inhibition rate of 200 and 250 μg/mL BGP was equivalent with Vc (P > 0.05). With concentration of 400 and 500 μg/mL, the OH radical inhibition rate of BGP was slightly lower than Vc (P > 0.05). The O2- radical inhibition rates of 200, 400, 600, 800 and 1000 μg/mL BGP were significantly lower than Vc (P < 0.05). In the groups treated with BGP with suitable dose, the serum MDA content was significantly decreased compared with model group (P < 0.05), and the serum SOD and GSH-Px activities were significantly increased (P < 0.05). BGP has obvious DPPH· and ·OH radical scavenging activities, and can significantly decrease the serum MDA content in mice with oxidative damage, and increase the serum SOD and GSH-Px activities.