FORMATION OF VOLATILE PYRROLE PRODUCTS FROM EPOXYALKENAL PROTEIN REACTIONS

The production of volatile compounds in the reaction of the lipid pero xidation product (E)-4,5-epoxy-(E)-2-heptenal with lysine or bovine se rum albumin was studied in order to characterise alternative mechanism s for production of volatile pyrrole derivatives in foods. A mixture o f the lipid and the amino acid or the protein was stirred overnight at 37 degrees C and the volatiles formed were collected using a Tenax TA trap. Several aldehydes, ketones, alkylfurans, alkyl- and acyl-pyrrol es, and alkylpyridines were identified by GC/MS. Formation of pyrrole derivatives in these reactions suggested the existence of alternative mechanisms for production of these flavour-associated compounds, previ ously considered to be formed mainly via Maillard reactions. This new route does not need the presence of sugars, and might contribute signi ficantly to volatile pyrrole production in foods under conditions unfa vourable for classic Maillard reactions.