Glutamic acid can prevent the browning of fresh-cut potatoes by inhibiting PPO activity and regulating amino acid metabolism

Enzymatic browning during fresh cutting and storage affects the quality and commodity value of fresh-cut po-tatoes. The study investigated the effects of glutamic acid (Glu) on browning of fresh-cut potatoes. The results showed that Glu treatments significantly reduced the browning of potato pulp and shreds. Treated with the optimum concentration of 15 g/L Glu for 4 min prolonged the shelf-life of fresh-cut shredded potatoes to 5 d at 2-4 degrees C. Further research revealed that Glu treatment could inhibit the content of the total phenols, regulate the content of 16 free amino acids and repress the activity of polyphenol oxidase (PPO) via lowering pH value and chelating Cu2+. Molecular docking indicates that Glu stable bound to the active site of PPO. These results in-dicates that Glu treatment can inhibit the browning of fresh-cut potatoes by inhibiting PPO activity and the total phenolic content and regulating amino acid metabolism.