Comparison of pyrazines formation in methionine/glucose and corresponding Amadori rearrangement product model

• Pyrazine formation from methionine/glucose Amadori product (MG-ARP) is inefficient. • α -Aminocarbonyls condensation is the rate-limiting reaction in pyrazine formation. • Fast glyoxal depletion and a lack of diacetyl limit pyrazine yields in MG-ARP model. • Rapid drops of pH inhibit the production of pyrazines during MG-ARP degradation. • Inhibitory effect on pyrazine formation was reduced by the temperature increase. The generation of pyrazines in a binary methionine/glucose (Met/Glc) mixture and corresponding methionine/glucose-derived Amadori rearrangement product (MG-ARP) was studied. Quantitative analyses of pyrazines and methional revealed that MG-ARP generated more methional compared to Met/Glc, whereas lower content and fewer species of pyrazines were observed in the MG-ARP model. Comparing the availability of α -dicarbonyl compounds generated from the Met/Glc model, methylglyoxal (MGO) was a considerably effective α -dicarbonyl compound for the formation of pyrazines during MG-ARP degradation, but glyoxal (GO) produced from MG-ARP did not effectively participate in the corresponding formation of pyrazines due to the asynchrony on the formation of GO and recovered Met. Diacetyl (DA) content was not high enough to form corresponding pyrazines in the MG-ARP model. The insufficient interaction of precursors and rapid drops in pH limited the formation of pyrazines during MG-ARP degradation. Increasing reaction temperature could reduce the negative inhibitory effect by promoting the content of precursors.