Browning is the process of food turning brown due to the chemical reactions that take place within. The process of food browning is one of the most important reactions that take place in food chemistry and represents an interesting research topic regarding health, nutrition, and food technology. Though there are many different ways food chemically changes over time, browning, in particular, falls into 2 main categories: enzymatic and non-enzymatic processes. The browning process of foods may yield desirable or undesirable results, depend on the type of food.
Enzymatic browning
Enzymatic browning is one of the most important reactions that takes place in most fruits and vegetables as well as in seafood.[3] These processes affect the taste, color, and value of such foods. Enzymatic browning (also called oxidation of foods) requires exposure to oxygen.
Examples of beneficial enzymatic browning:
- Developing color and flavor in Coffee, Cocoa beans, and tea.
- Developing color and flavor in dried fruit such as figs and raisins.
Examples of non-beneficial enzymatic browning:
- Fresh fruit and vegetables, including apples, potatoes, bananas and avocados.
- formation of Melanosis in crustaceans such as shrimp
Non-enzymatic browning
The second type of browning, nonenzymatic browning, is a process that also produces the brown pigmentation in foods, but without the activity of enzymes. The two main forms of non-enzymatic browning are caramelization and the Maillard reaction.
Caramelization is a process involving the pyrolysis of sugar. It is used extensively in cooking for the desired nutty flavor and brown color. As the process occurs, volatile chemicals are released, producing the characteristic caramel flavor.Examples of foods that undergo Maillard reaction include breads, steaks, and potatoes.