Formation of Pyrazines in Aqueous Maltose/Glucose/Fructose-Glutamine Model Systems upon Heating at below 100.DEG.C.

Pyrazines generated from aqueous sugar-glutamine model systems heated at 90°C were investigated quantitatively. To determine trace levels of pyrazines in aqueous matrices, an efficient method using solid-phase extraction (SPE) and gas chromatography/mass spectrometry (GCMS) was developed. A series of alkylpyrazines as well as trace levels of acetylpyrazines and bis-(2-furyl)pyrazines were detected in the model systems by this method. Remarkable difference in the formation of pyrazines between monosaccharide and disaccharide was observed. The yield of acetylpyrazines and bis-(2-furyl)pyrazines from maltose was larger than those from fructose and glucose, while that of alkylpyrazines was less. The pH dependency on the generation of pyrazines in maltose-glutamine model systems was also examined.