Abstract
Amino-carbonyl reaction has extensively occurred in food and biological systems. Low-molecular weight compounds formed by the amino-carbonyl reaction of carbonyl compounds-amino acids or amines have been identified as amides, furans, pyrroles, pyridines, pyrazines and so on.
Especially, pyrrole-carbaldehydes were major products of Maillard reaction. Melanoidins formed as final products of Maillard reaction were analyzed by 13C or 15N CP-MAS NMR. The nitrogen atoms of melanoidins were mostly assigned to pyrrole-like, conjugated enamine and amide nitrogens. Amino groups of proteins in biological system as well as food system react non-enzymatically with reducing sugars to form a Schiff base and Amadori compounds in an early stage. In an advanced stage of Maillard reaction, proteins such as collagen and lens crystallin are modified into colored, fluorescent and cross-linked molecules. These processes have been hypothesized to have an important role in the aging and the diabetic complications.
