Enzymatic browning in many food systems usually causes the undesirable appearance, but with a knowledge of the type of reaction involved, it is easier to work out methods for controlling this change. Basically, enzymatic browning can be defined as an initial enzymatic oxidation of endogenous phenols into slightly colored quinones.
These quinones are then subjected to further reactions, enzymatically catalyzed or not, leading to the development of pigments. When the surfaces of fruits and vegetables are cut, the browning occurred and is caused by reactions of the o-quinones. These are oxidations that are catalyzed nonenzymatically, followed by polymerization of the oxidation products.
Enzymatic browning is mostly linked with polyphenol oxidases, which are able to act on phenols in the presence of oxygen.
Enzymatic Browning Reactions
