Tobacco Science & Technology, 2011, 8, p. 55-61., ISSN.1002-0861

Study on nonaqueous phase Maillard reaction of glucose / L-lysine model system

1. Technology Center of Hongta Tobacco (Group) Co., Ltd., Yuxi 653100, Yunnan, P.R. China; 2. College of Chemical Science and Engineering, Yunnan University, Kunming 650091, P.R. China

The thermogravimetric characteristics of glucose, L-lysine and their mixture were determined by thermogravimetry. The pyrolytic products of glucose and L-lysine mixture at 5 temperature ranges were analyzed by the combination of thermogravimetry, solid phase microextraction and gas chromatography-mass spectrometry (TG-SPME-GC-MS). The effects of the proportion of glucose to L-lysine, and air flow on the yields of 2-ethyl-3, 5-dimethylpyrazine and 3,5-diethyl-2-methylpyrazine were invesitigated as well. The results showed that: 1) The activation energy of reaction of glucose / L-lysine model system was far lower than that of degradation on their own. There was an endothermic process at the early reaction stage. In the temperature range of 135 to 245 °C weight loss started, the mixture lost about 40% of its weight. 2) 39 compounds were identified in pyrolytic products of the model system. Ketones and furfurals were the main products at 100 to 250 °C. From 250 to 350 °C, pyrazine, pyridine, pyrrole, oxazole, imidazole and other nitrogenous heterocyclic compounds were detected. And the important flavor compounds were produced started from 150 °C. 3) The yields of 2-ethyl-3, 5-dimethylpyrazine and 3,5-Diethyl-2-methylpyrazine culminated at air velocity of 200 mL/min and the mass ratio of glucose to L-lysine of 1:1.