Reduction of omega-3 oil oxidation in stable emulsion of caseinate-omega-3 oil-oat beta-glucan

•Caseinate and β-glucan increased particle size and viscosity of emulsions.•Flaxseed oil emulsion is less stable than marine oil without caseinate.•Oat β-glucan has little effect on oxidation of ω-3 oil in the emulsions prepared.•Marine ω-3 oil is more prone to oxidation in emulsions than flaxseed oil.•Optimal composition of emulsion is made from 1 g caseinate/100 g, 0.3 g β-glucan/100 g, and 10 mL oil/100 g.

Lipid oxidation of ω-3 fatty acids has posed a serious challenge for incorporating heart-healthy oil products into healthful foods and beverages. In this study, plant and marine based ω-3 oils were dispersed into sodium caseinate dispersions and then mixed with purified heart-healthy oat gum comprised of 97% β-glucan in a homogenizer under room temperature. The stable emulsions underwent shelf life tests to assess their stabilities and oxidative activities. Various preparations of ω-3 oil-in-water emulsions with 10mL oil/100mLstabilized with sodium caseinate ranging from 0 to 3g caseinate/100g sample and β-glucan ranging from 0 to 0.3g β-glucan/100g sample were formed. The physical properties such as creaming index, particle size, and viscosity of the emulsions were measured. The lipid oxidation was measured as lipid hydroperoxide concentration and reduction of lipid oxidation was observed under shelf-life stress tests at 28 °C. The fatty acids of the oils were also measured using gas chromatography. Omega-3 fatty acids compositional changes were observed over the shelf life tests. It was found that caseinate helped reduce the oxidation of the oils in general and there is no significant impact of β-glucan on oxidation. Addition of caseinate and β-glucan in the emulsions slightly increased both particle size and viscosity.