Study of nonenzymic browning in α-amino acid and γ-aminobutyric acid/sugar model systems

摘要: Abstract The reactivities, in nonenzymic browning, of γ-aminobutyric acid (GABA), a non-protein amino with wide natural occurrence and potential health benefits as it occurs foods, the α- l -amino acids arginine, glutamic acid, glutamine, leucine, lysine, phenylalanine were investigated by heating equimolar mixtures glucose cited at 110 °C pH 6.0 for different times (0–4 h). Linear regression analysis indicated that colour development GABA/glucose mixture was slower than lysine/glucose comparable to phenylalanine/glucose mixture. High-performance anion-exchange chromatography (HPAEC) integrated pulsed amperometric detection (IPAD) showed decrease GABA levels ( ca. 10% after 4 h) function time smaller 30% 4 h). At same time, fructose isomerisation took place. After 20 min 6.0, all peak, area which increased time. However, correcting isomerisation, losses still higher losses. In contrast its precursor stable during solution containing alone. Heating GABA-containing d -sugar solutions (xylose, fructose, glucose, maltose sucrose) relative order yield pentose > hexose > disaccharides. As well HPAEC–IPAD allowed monitoring reactions occurring, also disaccharide hydrolysis GABA/sugar mixtures.