According to food safety agencies, it is of utmost importance that Western consumers readjust their lipid intake and that consumers opt for polyunsaturated fats. However, these fats are prone to oxidation during technological operations and during digestion. The resulting lipid oxidation products led to the development of off-flavours that decrease the acceptability of the products. They also could contribute to the development of several pathologies such as cardiovascular disease and colon cancer. It is therefore of interest to be able to predict development of oxidation in complex food formulations. Model emulsions were developed to assess the susceptibity to oxidation of milk fat as modulated by its composition and several formulation parameters, the pro-oxidant activity of foods or food components or the antioxidant efficiency of phenolic compounds in conditions that mimic the physico-chemical environment of lipids under gastric conditions.