Effect of antioxidants on the formation of volatiles from the Maillard Reaction

The aim of this report was to study the involvement of free radicals on the formation of volatiles from the Maillard reaction. An aqueous model system of glucose/lysine was heated in the presence of different amounts of antioxidants, such as α-tocopherol, 2,6-di-tert-butyl-4-methylphenol (BHT), and rosemary extract, or of α,α'-azobis-isobutyronitrile (AIBN) which is a pro-oxidant (free radical initiator). The differences in volatile formation between the standard model system and those with additives are relatively small. BHT, at pH 4, decreases pyrazine, while it increases slightly 2-methylpyrazine and 2,5-dimethylpyrazine and much more 2-acetylpyrrole, at pH 6 it produces a decrease in furaneol. α-Tocopherol, at pH 4, decreases pyrazine, furaneol, 2,3-dihydroxy-6-methyl-4H-pyran-4-one, and 2-acetylpyrrole, while at pH 6 it decreases 2-furanmethanol, and furaneol. Rosemary extract, at pH 4, decreases all the pyrazines and 2-furanmethanol and 2-acetylpyrrole; at pH 6 it produces a decrease of furaneol and 2,3-dihydroxy-6-methyl-4H-pyran-4-one. AIBN at both pH's decreases the pyrazines and increases 2-acetylpyrrole.