Investigation on Oxidative Stability of O/W Emulsion of Descurainia Sophia Seeds Oil, Encapsulated by Gum Arabic and Whey Protein Concentrate and the Effect of Ultra Sound Sonification on Changes in Oxidative Indices

This studywas aimed to fabricate O/W emulsions of Descurainia Sophia seeds oil in order to be stabilized against oxidation.Response surface methodology (RSM) was used to optimizing theprocess in which the gum Arabic (GA), whey protein concentrate (WPC), and sonication time were selected as independent variableswhere the peroxidevalue (meq/kg oil) was considered as a responsefactor. The optimum point was obtained when the WPC, and GA, and ultrasound treatmenttime were as 19.78%, 11.08%, and 0.1 s, respectively. In the associatedoptimum point, peroxide value was determined as 0.59 meq/kg oil. The emulsion oil droplets varied dependently to ultrasound time and WPCconcentrationwhich both decreased the oil droplets sizeswith more exposing and high concentration inclusion.Conversely, ultrasound applying resulted in higher peroxide values at the instantaneous determinations.The optimum emulsion indicated 916 nm with the -48 mV Zeta potential. The respective sample exhibited shear thinning behavior which more effectively attributed to WPC existence. Oxidation stability of the emulsion samples compared with crude oil and the oil treated with 30 s ultrasound. The results indicated that the GA and WPC effectively preserved the oil during 28 d at the intensifying circumstances (50 °C)and the free oils were oxidized more intensively. GA due to steric repulsion structure forming in the vicinity of oil droplets and WPC due to electrostatic repulsion, produced a complexbiopolymer structure which had potentially antioxidant and coating attributes.