Dual Effects of Propyl Gallate and Its Methylglyoxal Adduct on Carbonyl Stress and Oxidative Stress

Abstract In the present study, we investigated the trapping of methylglyoxal (MGO) by propyl gallate (PG), a known food grade antioxidant, and the anti-carbonyl and anti-oxidative properties of the mono-MGO adduct of PG (MM-PG). Our result indicated that more than 77.5% MGO was suppressed by PG after a 30 min incubation of PG with MGO, which was much more effective than gallic acid (15.2%). For the first time, MM-PG was purified, and its structure was elucidated based on the analysis of its 1 H, 13 C, and 2D-NMR data. We also demonstrated that MM-PG had strong anti-oxidative and anti-carbonyl activities. Furthermore, PG could trap the MGO generated during the preparation of roasted pork, and both mono- and di- MGO adducts of PG were detected in the roasted pork system using LC/MS technique. Thus, PG could be widely applied in the food system for inhibiting the formation of both carbonyl species and oxidative species.