Discoloration in HPP-treated peaches occurs as a consequence of the process, and the hypothesis is that cell integrity is the primary determining factor affecting enzymatic browning reactions in refrigerated and stored high-pressure processed peaches.
After loss of fruit cell integrity, the enzyme polyphenol oxidase(PPO), initially located in the plastids, and the phenolic substrates, initially located in the vacuole, are allowed to interact, creating brown products.