Fats and aromas in animal products: the example of meat

Muscle lipids consist of triacylglycerols (TGs) and phospholipids (PLs) whi ch have different physical and chemical properties. The TGs, which are less reactive than PLs, are good solvents of aroma compounds. PLs, the most rea ctive lipids, play a key role in the formation of aroma compounds. Pls dire ctly provide many volatiles through oxidation because they contain a large amount of long chain polyunsaturated fatty acids (10-15%) and they modulate the formation of the volatiles arising from other reactions such as the Ma illard reaction. lipids are involved in off-favour when they are too oxidis ed. However, they also contribute to the positive aroma of meat because spe cies-specific aroma comes from lipids and because lipids modulate the forma tion of the compounds of typical cooked meat aroma arising from the Maillar d reaction. The overall aroma of cooked meal results from the equilibrium b etween aroma compounds arising from lipid oxidation and from Maillard react ion. Even if a large part of the factors involved in the control of this eq uilibrium remains unknown, lipid oxidation can be controlled through dietar y lipids (decrease in polyunsaturated fatty acid supply, increase in vitami n E supply).