Lipid oxidation control in food emulsions enabled by natural strategies

Many food products can be represented as oil-in-water (O/W) emulsions, with oil droplets dispersed in a continuous aqueous phase. Typical examples of such products include dressings, sauces, mayonnaise, dairy products, or infant formulas. One trend in the formulation of such food emulsions has been to increase the amounts of polyunsaturated fatty acids (PUFAs) in the oil phase, because of their health benefits. However, PUFAs readily oxidize, which damages the sensory and nutritional quality of the products. Therefore strategies need to be developed to prevent lipid oxidation in food emulsions. This is, however, intrinsically difficult, as lipid oxidation depends to a large extent on the physical organisation of the matrix, such as the composition and structure of the interfacial layer between oil and water. Besides, the developed strategies have to comply with consumers’ wishes, such as the ‘clean label’ trend, which excludes the use of synthetic antioxidants, such as EDTA.

In this project, we intend to address the problem from an interface and colloid science perspective:

Ø  We investigate components (e.g., proteins, antioxidants) at the surface of the oil droplets, characterise the structure of the resulting interfacial layers, and link this to oxidative stability of the emulsions. The chosen components are of natural origin, e.g., oleosins. We want to use this knowledge for the controlled design of oil-water interfaces that can prevent lipid oxidation, using natural strategies.

Ø  We are also interested in the continuous phase of the emulsion: are lipid oxidation intermediate products transported through the continuous phase, and if yes, how fast is this process, and which components are transported? Is it possible to limit inter-droplet propagation of the reaction by altering the molecules and colloidal structures present in the continuous phase?

Ø  In parallel, we want to develop a microfluidic platform to produce model emulsions for this project, so that we can make many types of emulsions, in small volumes. This will be of great help to screen a number of variables for emulsion formulation.

A new project will cover the fundamental aspects of lipid oxidation in emulsions.