he Maillard reaction is complex. The reaction of the sugar glucose and the simple amino acid glycine gives more than 24 reaction products. In many foods, there are five or more sugars and as many as 20 or more amino acids, and they can all react when heated to create the brown color we find on toast. That color is made up largely of melanoidins – large molecules that polymerize from the products of the Maillard reaction.