The role of chicory furaneol in reducing potato browning: Inhibiting polyphenol oxidase activity and enhancing antioxidant capacity

Abstract

Using safe browning inhibitors is an important strategy for preventing enzymatic browning of fresh-cut produce. This research first compared the inhibitory capacity of eight food-derived furan compounds on polyphenol oxidase (PPO), and investigated the anti-browning effect of the selected compound on fresh-cut potatoes. Then, the underlying mechanism of its browning inhibition was further explored. The results indicated among the eight furan compounds, chicory furaneol, naturally existing in fruit and vegetables, exhibited strong inhibitory effects on PPO. At 4 °C, treatments with 4.5 and 9 mM chicory furaneol extended the shelf life of fresh-cut potato chips to over 10 d, compared to less than 1 d for the control. The chips treated with chicory furaneol had a slight caramel odor, which was acceptable in sensory evaluation and dissipated quickly during heating. Kinetics analysis indicated that chicory furaneol was a mixed-type PPO inhibitor, with a stronger affinity for the free enzyme. Copper ion chelation experiments and molecular docking simulations demonstrated that chicory furaneol chelated the copper ions in the active center of PPO and interacted with various amino acid residues. Antioxidant experiments revealed that chicory furaneol possessed strong antioxidant capabilities and enhanced the antioxidant capacity of potato pulps. Correlation analysis showed that the browning inhibition of chicory furaneol was primarily achieved through the inhibition of PPO activity and the enhancement of antioxidant capacity. This study provides a potential safe browning inhibitor for solving the browning issues of fresh-cut potatoes.