Can microencapsulated vitamin C prevent browning of fruit and vegetable products during cooking or storage?
The Browning or Maillard reaction is a non-enzymatic browning that results in condensation of an amino group with a reducing compound, often a sugar. This reaction results in complex changes in biological and food systems. Louis Maillard described this process in 1912. The Browning reaction occurs when foods containing protein and reducing sugars are heated; it also occurs gradually during storage at any temperature. Some effects of the Browning reaction, including the caramel aromas and golden brown colors, are desirable. However, other effects of are undesirable; these include foods darkening, development of off-flavors, and reduced bioavailability of certain amino acids, especially lysine.
Research in recent years has sought effective and economical methods to prevent browning in various fruit and vegetable products. Concerted efforts have been made to understand the basic biochemistry involved in enzymatic browning reactions of various fruits and vegetables and to find practical approaches to reduce or prevent the browning reactions of both fresh and processed products. For years, cookbooks have recommended the dipping fruits and fruit products in a solution of ascorbic acid (vitamin C) or lemon juice (to supply citric and ascorbic acid) to prevent browning and discoloration of products being stored, canned, or frozen. Gunes and Lee (J. Food Sci. 62:572-5, 582; 1997) further demonstrated that dipping potato chips in Ascorbic Acid delayed the onset of browning for several days. Dipping of fruits and vegetables in a solution of Ascorbic Acid is not as convenient as powdering a fruit or vegetable product with a dry form of ascorbic acid. Unfortunately, unprotected ascorbic acid is readily oxidized and loses its activity when exposed to air. Thus, for processed fruits and vegetables and their products, a microencapsulated Ascorbic Acid, through its increased stability in air and more gradual release over time of its antioxidant (Oxygen scavenging) properties should be a convenient and effective method to protect against darkening of fruit and vegetables and their products. Like dipping in ascorbic acid, a powdered encapsulated ascorbic acid will prevent some of the adverse effects of the Browning Reaction. Besides extending the shelf life of fruits and vegetables and their products, microencapsulated Ascorbic Acid also provides added nutritional value through product fortification with vitamin C.