Xanthone-related compounds as an anti-browning and antioxidant food additive.

Although enzymatic browning is important for the beneficial coloration of some foods, it also causes negative effects on safety, quality, and nutritional values of fruit and vegetable. Thus, anti-browning natural compounds have gained attention in the food industry. Xanthone-related compounds have been well-known for its biological activities, but their roles in enzymatic browning are unclear. We screened xanthone-related natural compounds for their anti-polyphenol oxidase (PPO) activity and maclurin was selected for further experiments due to stronger PPO-inhibitory activity. Maclurin suppressed enzymatic browning in potato supernatant for long-term partly through direct binding to and inactivating PPO presumably by forming multiple hydrogen bonds and aromatic interactions with the binding pocket. In addition, maclurin elevated antioxidant capacity when added to potato supernatant. Considering the diverse health-promoting effects of antioxidants, maclurin can be applied as a functional food additive to block enzymatic browning and increase the antioxidant property of foods including beverages and soups.