Browning of fruits and vegetables is a common problem in food sector. This enzymatic process compromises the quality of post-harvest produce and leads to large quantity of food spoilage and economic loss.
Firmness, taste and flavor of the produce are degraded, leading to lowered shelf life. The chemical reaction underlying this process has been identified as the activity of enzyme polyphenoloxidase (PPO) or phenolase.
Most fresh agricultural produce are susceptible to the browning; however are affected more. Among fruits the stone fruits (apricots, pears, plums), apple, bananas, litchi, grapes, pineapple, berries mangoes, melons are easily browned.
Like this banana, rendered soft and unedible...
Among vegetables, potatoes, mushrooms, broccoli, spinach, peas, avocados, lettuce are easily affected. However, the very same process of browning benefits other plant-based food products like tea, coffee, cocoa, raisins, prunes.