Enzymatic reactions in foods
Foods may develop a variety of brown colors, from yellow-brown to red-brown to black-brown, during handling, processing, and storage. These colors are desirable in certain foods (e.g., coffee, beer, bread, maple syrup). In other foods, such as most dehydrated fruits and vegetables, dried eggs, and canned or dried milk, browning is detrimental. Even when desirable, browning should not be excessive, as in potato chips, french fries, and apple juice. Numerous reactions lead to browning in foods. Some of these may also generate flavours and/or alter the nutritional properties of foods.
Enzymatic Browning: Several enzymes may initiate reactions that eventually produce brown colors in foods known as enzymatic browning.Non Enzymatic Browning: A number of chemical processes not involving enzymes may result in food browning.