Evaluation of the Physical and Oxidative Stabilities of Fish Oil-in-Water-in-Olive Oil Double Emulsions (O1/W/O2) Stabilized with Whey Protein Hydrolysate Padial Domínguez, Marta García Moreno, Pedro Jesús González-Beneded, Rubén Guadix Escobar, Antonio María Guadix Escobar, Emilia María Double emulsions Omega-3 polyunsaturated fatty acids Protein hydrolysates Lipid oxidation This work studied the physical and oxidative stabilities of fish oil-in-water-in-olive oil double emulsions (O1/W/O2), where whey protein hydrolysate was used as a hydrophilic emulsifier. A 20 wt.% fish oil-in-water emulsion, stabilized with whey protein hydrolysate (oil: protein ratio of 5:2 w/w) and with a zeta potential of ~�����40 mV, only slightly increased its D4,3 value during storage at 8 C for seven days (from 0.725 to 0.897 m), although it showed severe physical destabilization when stored at 25 C for seven days (D4,3 value increased from 0.706 to 9.035 m). The oxidative stability of the 20 wt.% fish oil-in-water emulsion decreased when the storage temperature increased (25 vs. 8 C) as indicated by peroxide and p-anisidine values, both in the presence or not of prooxidants (Fe2+). Confocal microscopy images confirmed the formation of 20 wt.% fish oil-in-water-in-olive oil (ratio 25:75 w/w) using Polyglycerol polyricinoleate (PGPR, 4 wt.%). Double emulsions were fairly physically stable for 7 days (both at 25 and 8 C) (Turbiscan stability index, TSI < 4). Moreover, double emulsions had low peroxide (<7 meq O2/kg oil) and p-anisidine (<7) values that did not increase during storage independently of the storage temperature (8 or 25 C) and the presence or not of prooxidants (Fe2+), which denotes oxidative stability. 2023-05-16T08:07:35Z 2023-05-16T08:07:35Z 2023-03-21 info:eu-repo/semantics/article Padial-Domínguez, M.; García-Moreno, P.J.; González-Beneded, R.; Guadix, A.; Guadix, E.M. Evaluation of the Physical and Oxidative Stabilities of Fish Oil-in-Water-in-Olive Oil Double Emulsions (O1/W/O2) Stabilized with Whey Protein Hydrolysate. Antioxidants 2023, 12, 762. [https://doi.org/10.3390/antiox12030762] https://hdl.handle.net/10481/81565 10.3390/antiox12030762 eng info:eu-repo/semantics/openAccess MDPI