The Maillard reaction occurs widely in food and biological systems. This contribution reviews the relation between the Maillard reaction and food processing, particularly its contribution to flavor formation, antioxidative effects, desmutagenic activity and the improvement of protein functional properties. Proteins modified by glucose, and melanoidins are important components of foodstuffs while the reactions of amino acids or peptides with glucose or dicarbonyl compounds produce various kinds of flavor components. Melanoidins and Amadori rearrangement products play an important role in providing antioxidative effects, both in vitro and in vivo. Melanoidins also exhibit desmutagenic activity against carcinogenic compounds. Protein-polysaccharide conjugates, prepared by Maillard reaction at mild conditions, increase the emulsifying activity, as well as antioxidative and antimicrobial effects of the original proteins.