Food anoxia and the formation of either flavor or toxic compounds by amino acid degradation initiated by oxidized lipids.

Amino acid degradation plays an important role in the formation of both flavors and toxic compounds during food processing. These reactions are produced, to a significant extent, as a consequence of the Maillard reaction among amino acids and carbohydrates. However, recent studies have shown that lipids also take part in these reactions. This article reviews the current knowledge of the contribution of lipids to both flavor and toxic-compound formation by amino acid degradation, describing the formation of Strecker aldehydes and the conversion of amino acids into their vinylogous derivatives as a consequence of lipid-amino acid reactions. Current data suggest that amino acids can be converted into either Strecker aldehydes or vinylogous derivatives by many lipid derivatives, which exhibit diverse reactivities for both reactions. Reaction conditions, including the presence of oxygen, also play a major role in the Strecker aldehyde/vinylogous derivative ratio obtained. Nevertheless, the high number of lipid derivatives involved, the different alternative pathways, and the existence of both positive and negative synergisms between lipids and carbohydrates make it hard to predict the effect of reaction conditions in the Strecker aldehyde/vinylogous derivative ratio obtained in complex food systems.