Interactions between phospholipids, saccharides and oxidized lipids in non-enzymic browning reactions

Abstract In addition to browning products analogous to those occurring in oxidizing lipids, other types of browning reactions were observed that produced by intermolecular or intramolecular interactions between amine groups of phospholipids and hydroperoxides or their carbonylic degradation products. Primary amine groups of phosphatidylethanolamine, phosphatidylserine and the respective lysophospholipids react with oxidized acyl chains of phospholipids, forming yellow or red oxidation products. Polyunsaturated imines (Schiff bases) are formed, which rapidly turn brown. The presence of amine groups accelerates browning reactions, slowly on storage, rapidly on heating.