GENERATION AND THE FATE OF C_2, C_3, AND C_4 REACTIVE FRAGMENTS FORMED IN MAILLARD MODEL SYSTEMS OF ~(13)CGLUCOSE AND ~(13)CGLYCINE OR PROLINE

摘要

Model studies with pyrolysis/GC/MS using labeled [~(13)C] glucoses with labeled [~(15)N/~(13)C]glycines and proline have indicated that the Maillard model systems consisting of glucose and glycine or proline generate similar C_2, C_3, C_4 fragments such as acetic acid, and pyruvaldehyde. Furthermore, the labeling studies have enabled the identification of the origin of these reactive intermediates and their stable end-products such as N-acetylpyrrolidine, 1-(1'-pyrrolidinyl)-2-propanone amd 1-(1'-pyrrolidinyl)-2-butanone in proline model system and pyrazines and pyrazinones in glycine. In glycine model system, pyruvaldehyde and 2,3-butandione were found to be formed either from the degradation of the carbohydrate moiety (90 and 35%, respectively) or by an aldol-type interaction of glycine with α-ketoaldehydes. The same intermediates in proline system are formed exclusively from the carbohydrate degradation pathway.