Lipid-amine browning reaction

Pyrroles are common products in the reaction of different lipid oxidation products with primary amino groups of amines, amino acid, and protein (Zamora et al., 2000). For example, when squid microsomes were oxidized with iron and ascorbate, TEARS increased simultaneously with the -value (yellowness) and pyrrole compounds, concomitantly with a decrease in free amines. Off-color formation in squid muscle could be due to the nonenzymatic browning reactions occurring between aldehydic lipid oxidation products and the amines on phospholipids head groups... 

Complex mixtures are produced by non-enzymatic browning reactions between thermally oxidized lipids and amines, amino acids and proteins (see Chapter 11.B.4). Interactions between aldehydes, epoxides, hydroxy ketones, and dicarbonyls with proteins cause browning that has been related with losses of lysine, histidine, and methionine. Schiff base formation results in polymerization to form brown macromolecules. Interactions between epoxyalkenals formed at elevated temperatures and reactive groups of proteins produce protein pyrroles polymers and volatile heterocyclic compounds. Much of the published research in this complex chemical area was based on model systems. More stmctural information is needed however with real foods subjected to frying conditions. 

Chapter 12 on Frying contains new material on complex interaction compounds produced by non-enzymatic browning reactions between thermally oxidized lipids and amines, amino acids and proteins. This chapter... 

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