ABSTRACT
Non-enzymatic catalyzed browning reactions in food and drink are classified into several distinct reaction types including lipid oxidation, caramelization, ascorbic acid oxidation, and the Maillard reaction. The Maillard reaction, a condensation of a reducing sugar with amino groups of amino acids, peptides, or protein, is a complex reaction with multiple phases and possible pathways providing a multitude of possible colored and flavored compounds. All free amino acids have the potential to be a Maillard reaction via the free amino group. Interestingly, besides lysine, glycine, tryptophan, and tyrosine all react strongly with reducing sugars, providing a significant Maillard product. Glycine has been reported to increase the formation of this set of products, presumably as this increases the reaction from the Amadori product over an alternative degradation of glucose without utilizing the Maillard reaction. While many intermediates provide both volatile and soluble components of flavor and aroma, the reactions generate brown-colored compounds as well as flavors.
