Reactive carbonyl species as key control point for optimization of reaction flavors

The objective of this work was to characterize Maillard-derived reactive carbonyl species (RCS) involved in the thermal generation of the popcorn smelling compound, 2-acetylpyridine and develop a targeted approach to optimize the RCS composition and reaction yield. Formation of 2-acetylpyridine from the reaction of glucose and proline was investigated using the carbon module labeling technique and gas chromatography/mass spectrometry. Incorporation of C3 transient carbonyl compounds was identified as the main route of 2-acetylpyridine formation. Further isotope labeling experiments were carried out to characterize the RCS composition of the reaction mixture using liquid chromatography coupled to time-of-flight mass spectrometry. 1,3-Dihydroxyacetone and acetol, were suggested as key precursors of 2-acetylpyridine. The formation of these specific RCS was subsequently optimized using response surface methodology and a pre-thermal reaction, that ultimately resulted in a 2-fold increase in 2-acetylpyridine. In summary, RCS were demonstrated as a new control point for reaction flavor development.