Room temperature encapsulation of algae oil in water insoluble gluten extract

Abstract A high throughput encapsulation technique termed as emulsion electrospraying assisted by pressurized gas (EAPG) was used to encapsulate nanodroplets of DHA-enriched algae oil into wheat gluten extract at room temperature for the first time. Wheat gluten extract is of great value for the functional food industry due to its amphiphilic, mucoadhesive and antioxidant properties, and to preserve its integrity in aqueous-based food products. Raisin-like particles with sizes between 3 and 4 µm were obtained. Regarding the microparticles internal structure, nanodroplets of the oil were homogeneously distributed within the encapsulating matrix, thanks to the use of the emulsion. The bioactive properties of the oil were maintained during the encapsulation process, since the peroxide value was kept below 3 meq/kg. The wheat gluten extract demonstrated to provide good oxidative stability to the algae oil, as determined by ATR-FTIR spectroscopy and peroxide value during an accelerated oxidation test. Organoleptic tests performed with the encapsulates and the free algae oil in reconstituted milk powder suggested that encapsulates offered a reduced organoleptic impact. These results show that the combination of the EAPG process with the wheat gluten extract as an encapsulating matrix could become a promising technology for the encapsulation of sensitive bioactive compounds with application in functional foods, pharmaceuticals or cosmetics.