Biochemical and Nutritional Significance of the Reaction between Proteins and Reducing Sugars

Abstract

IT has long been known that amino-acids and reducing sugars react when heated together in concentrated aqueous solution (the Maillard reaction), probably first by interaction between the amino- and aldehyde-groups, and afterwards by a complicated series of changes leading to darkening, evolution of carbon dioxide and the formation of tarry products. A similar kind of reaction occurs with proteins, and we have recently been able to isolate the first stage of the process and to demonstrate that, under very mild conditions (approximately 13 per cent moisture, neutral pH and 37° C.), as much as 7 per cent of reducing sugar can be firmly bound to a protein—almost entirely at the free amino-groups—without impairing its colour or solubility.