title: Kinetics of browning and correlations between browning degree and pyrazine compounds in l-ascorbic acid/acidic amino acid model systems.
abstract: The kinetics of browning and the correlation between browning products (BPs) and pyrazine compounds were investigated by heating equimolar l-ascorbic acid (ASA)/acidic amino acids under weak alkaline conditions at 120-150°C for 10-120min. The formations of BPs and pyrazine compounds from the reaction were monitored by UV-vis and SPME-GC-FID, respectively. The formation of BPs in both ASA/l-glutamic acid and ASA/l-aspartic acid model reaction systems followed zero order reaction kinetics with activation energies (Ea) of 90.13 and 93.38kJ/mol, respectively. ASA/l-aspartic acid browned at a slightly higher rate than ASA/l-glutamic acid. The total concentration of pyrazine compounds was highly and positively correlated with that of BPs. Based on the observed kinetic data, the formation mechanisms of BPs and pyrazine compounds were proposed.
authors.affiliation: Key Laboratory of Biologic Resources Protection and Utilization of Hubei Province, Enshi, Hubei 445000, China; School of Chemistry & Environmental Engineering, Hubei University for Nationalities, Enshi, Hubei 445000, China. Electronic address: anyufoodchem@hotmail.com.
authors.forename: Ai-Nong
authors.initials: AN
authors.lastname: Yu
authors.affiliation: School of Chemistry & Environmental Engineering, Hubei University for Nationalities, Enshi, Hubei 445000, China.
authors.forename: Yong-Yan
authors.initials: YY
authors.lastname: Zhou
authors.affiliation: School of Chemistry & Environmental Engineering, Hubei University for Nationalities, Enshi, Hubei 445000, China.
authors.forename: Yi-Ni
authors.initials: YN
authors.lastname: Yang
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D001205:Ascorbic Acid / Q000737:chemistry*; D001224:Aspartic Acid / Q000737:chemistry; D018698:Glutamic Acid / Q000737:chemistry; D007700:Kinetics; D015416:Maillard Reaction; D008954:Models, Biological; D011719:Pyrazines / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D011719:Pyrazines; D001224:Aspartic Acid; D018698:Glutamic Acid; D001205:Ascorbic Acid
keywords: Acidic amino acids; Aroma; Ascorbic acid; Kinetics; Maillard; Non-enzymatic browning reaction