Objective: Polyphenol oxidase or PPO (EC 1.14.18.1) is considered the enzyme responsible for quality deterioration and browning in different fruits during postharvest period. The objective of this study was to evaluate the antibrowning (inhibition of polyphenol oxidase activity) effect of Cysteine, Ascorbic acid, citric acid, kojic acid and glycine at two different pH (6 and 7) in  hawthorn. Me...