Functional foods containing omega-3 polyunsaturated fatty acids (PUFA) is one of the food product categories with higher potential in Europa and North-America. This is due to the low consumption of fish-, krill or algae-based products by these populations and to the numerous beneficial health effects of omega-3 PUFA on human health (as recognized by the European Food Safety Authority, EFSA). However, omega-3 PUFA are highly susceptible to oxidation, which lead to the loss of nutritional value as well as the formation of unpleasant off-flavors and toxic compounds. Therefore, lipid oxidation must be prevented in order to successfully develop foods enriched with omega-3 PUFA.
Omega-3 PUFA can be added to foods as neat oils or as a “delivery system” such as microencapsulated oil powders and oil-in-water emulsions. Nevertheless, the development of alternative omega-3 PUFA delivery systems, which are easy to disperse and which will lead to improved oxidative stability of omega-3 enriched food products, is required by the food industry in order to benefit the consumer.
In this regard, the ELECTRONANOMEGA project aimed at developing: i) advanced omega-3 nano-microdelivery systems by using electrohydrodynamic processes, and ii) fortified food containing these delivery systems. Electrospinning and electrospraying processes allow the encapsulation of bioactive compounds in nano-microfibers or nano-microcapsules, respectively. These processes, in contrast to spray-drying, do not require heat for the drying of the parent emulsion which is beneficial for the stability of thermo-sensitive compounds such as omega-3 PUFA. Moreover, nano-microcapsules obtained by electrospraying have a reduced size compared to microcapsules produced by spray-drying. This is beneficial both in terms of incorporation of the encapsulates into the food matrix and of the release of the bioactive compound, but it is a challenge in terms of oxidative stability due to a larger specific surface area.
Overall, ELECTRONANOMEGA project has delivered the following:
- Suggestions of type of biopolymers (incl. concentration and type of solvents) and process conditions for the production of nano-microstructures containing omega-3 PUFA by electrohydrodynamic processes.
- Optimum approaches to incorporate fish oil and natural antioxidants in order to improve the oxidative stability of the biopolymeric nano-microstructures.
- Nano-microstructures (both nano-microfibers and capsules) with appropriate structural-functional properties and with adequate oxidative stability after production.
- Process conditions selected for the incorporation of fish oil-loaded nano-microcapsules into mayonnaise (40 wt%. total fat). Fortified mayonnaise with good structural-functional properties has successfully been produced.
It has to be mentioned that the oxidative stability during storage of the nano-microstructures obtained and of the enriched mayonnaise needs to be further improved. In this regard, it seems necessary to further reduce the oil droplets on the surface (or close to the surface) of the nano-microsctructures, which are easily oxidized due to its large area of contact with prooxidants.
