Changes in human dietary habits derived from changes in lifestyle have led to a relative deficiency of n-3 polyunsaturated fatty acids (PUFA) in developed countries. Overall, the ratio of n-6/n-3 PUFA in the modern diet is as high as 20-25:1 instead of the ideal ratio of 4-10:1. Nowadays, efforts are being directed to incorporate n-3 PUFA in foods rather than be used solely as a dietary supplement. Development of foods fortified in these essential fatty acids is emerging in order to allow increased dietary intakes with little change in dietary habits.

However, such fortification presents challenging limitations, as these lipid substrates are highly susceptible to lipid oxidation. Further, the growing development of these products contrasts, however, with the lack of analytical methods suitable for quality control, in particular, concerning the formation of oxidation compounds.

This project is aimed at contributing to the improvement of quality and safety of functional food ingredients containing n-3 PUFA by studying two specific aspects considered of priority interest:
1) Quantification of oxidation compounds formed during manufacturing and storage. Quantitative analysis of total oxidised triacylglycerols (TAG) and their distribution in three main groups of compounds, namely TAG polymers, TAG dimers and oxidised TAG monomers will be performed. In addition, specific determination of the altered acyl groups of the oxidised TAG molecules by a rapid analytical method will be developed.
2) Definition of the action of those variables to be modified and/or controlled to guarantee high quality and safety. It will be focused on those variables determining the contact of the lipids with oxygen, as a very low amount of oxygen is sufficient in heterogeneous lipid systems for development of off-flavours. Among the variables determining oxygen availability, the amount of occluded air, lipid surface area and oxygen permeability will be studied and optimised.