Promoted formation of pyrazines by targeted precursor addition to improve aroma of thermally processed methionine-glucose Amadori compound.

The methionine/glucose (Met/Glc) and methionine/glucose-derived Amadori rearrangement product (MG-ARP) models were established to analyze their differences in flavor profiles and aroma potentiality. The principal component analysis revealed the advantage of MG-ARP in the formation of low temperature-induced processing flavor. MG-ARP exhibited superior potential in the rapid formation and high intensity of processed flavor than the Met/Glc except for the inefficiency in pyrazine production. The extra-added Glc tended to react with recovered Met to compete against α-dicarbonyl compounds to suppress the Strecker degradation and pyrazine formation. The additional Met effectively improved the precursor availability and facilitated the conversion of C6-α-dicarbonyl compounds to short-chained α-dicarbonyl compounds for pyrazine formation rather than their dehydration and cyclization to generate furans. The oxidation of Met favored the nonoxidative carbohydrate degradation leading to MGO formation and the aldolization of dihydropyrazines, which synergistically enriched the varieties of pyrazines, especially for the promoted formation of long-chain substituted pyrazines.