Kinetics of Pyrazine Formation in Amino Acid‐Glucose Systems

The chemistry and kinetics of pyrazine formation were studied in four amino acid‐glucose model systems. Different amounts of the same alkylpyrazines were produced in the four systems. The most abundant alkylpyrazine generated in a gylcine‐glucose system was 2,3,5‐tri‐methylpyrazine, while 2‐methylpyrazine was most abundant in an arginine‐glucose system and 2,5‐dimethyIpyrazine predominated in a histidine‐glucose system. 2‐MethyIpyrazine and 2,5‐dimefhylpyrazine were the two most abundant alkypyrazines in a lysine‐glucose system. Kinetic data from the arginine‐glucose system indicated that each of four selected pyrazines was formed by a pseudo‐zero‐order reaction. Activation energies in the same system were determined to be 19.5 ± 4.1 Kcal mole −1 for pyrazine, 24.8 ± 8.7 Kcal Mole″ 1 for 2‐methylpyrazine, 20.8 ± 4.7 Kcal mole −1 for 2,6‐dimethylpyrazine and 29.0 ± 3.8 Kcal mole −1 for 2‐methyl‐6, 7‐dihydro‐5H‐cyclopen‐, tapyrazine.