Microwave-Assisted Synthesis and Extraction of Selected Maillard Reaction Products

To take advantage of the chemical diversity of the products formed during Maillard reaction, a focused microwave system under atmospheric pressure was used to synthesize and extract selected Maillard reaction products. l-Phenylalanine or glycine/d-glucose mixtures were sequentially treated with microwave irradiation in an aqueous media to initiate the synthesis step followed by irradiation in an microwave-transparent solvent to perform extraction of the products formed. The phenylalanine model system generated a mixture consisting of benzeneacetaldehyde (48%), 2-(5'-(hydroxymethyl)-2'-formylpyrrol-1'-yl)-3-phenylpropionic acid lactone (34%), 3,5-diphenylpyridine (4%) and an unknown compound (14%). The glycine model system, on the other hand, generated a mixture consisting of 1,6-dimethyl-2(1H)-pyrazinone (4%), 1,5,6-trimethyl-2(1H)-pyrazinone (19%), 5-hydroxy-1,3-dimethyl-2(1H)-quinoxalinone (62%), and two unknowns with molecular weights of 204 (10%) and 152 (5%). Keywords: Microwave-assisted synthesis; Maillard reaction; glycine; phenylalanine