Non-emulsion-based encapsulation of fish oil by coaxial electrospraying assisted by pressurized gas enhances the oxidative stability of a capsule-fortified salad dressing

The influence of the encapsulation technology (spray-drying, mono- or coaxial electrospraying assisted by pressurized gas, EAPG) and the oil load (13, 26 or 39 wt%) on the oxidative stability of: i) fish oil-loaded capsules, and ii) capsule-fortified salad dressings were investigated. The highest encapsulation efficiency (EE > 83%) was achieved by the emulsion-based encapsulation methods (e.g., spray-drying and monoaxial EAPG), irrespective of the oil load. Nonetheless, monoaxially EAPG capsules were the most oxidized during storage due to their increased surface-to-volume ratio. On the contrary, non-emulsion-based coaxial EAPG resulted in low lipid oxidation after processing and subsequent storage. The oxidative stability of the capsule-fortified salad dressings correlated well with that of the encapsulates, with the dressing fortified with the coaxially EAPG capsules showing significantly lower levels of oxidation. Our results show that the fortification approach (e.g., emulsion or non-emulsion-based delivery systems) significantly influenced the oxidative stability of the enriched food matrix.

This work was supported by the I + D + i projects CTQ2017-87076-R and PID2020-114137RB-I00 funded by MCIN/AEI/10.13039/501100011033/. N. E. Rahmani-Manglano acknowledges a FPI grant PRE2018-084861 funded by MCIN/AEI/10.13039/501100011033. C. Prieto wants to thank the Valencian Ministry of Innovation, Universities, Science and Digital Society for her postdoctoral grant (CIAPOS/2021/45). The authors are grateful to Cristina Coronas and to Alberto Rodríguez for their invaluable help in the production of the encapsulates. The authors are also thankful to T. T. Trang-Vu and Lis Berner for her skilful help with the production and physicochemical characterization of the fortified food matrix. Funding for open access charge: Universidad de Granada/CBUA.

Peer reviewed