Formation, rheology and susceptibility to lipid oxidation of multiple emulsions (O/W/O) in table spreads containing omega-3 rich oils

Abstract

Novel multiple emulsion technology was used to enrich spreads (oil-in-water-in-oil, O/W/O, emulsions) with omega-3 rich oils. Effects of oil type (camelina, fish, camelina–fish oil blends) on lipid oxidation (lipid hydroperoxide values; p-Anisidine values), confocal imaging, rheology, and firmness of spreads (75 g/100 g fat), throughout storage at 5 °C, were examined. Fish oil had higher lipid hydroperoxides and p-Anisidine values (p-Avs) than camelina oil (P < 0.05). As the ratio of camelina oil (C) blended with the fish oil (F) was increased (72:28, 85:15, 95:5), lipid hydroperoxides and p-Avs decreased (P < 0.05). Lipid hydroperoxides of spreads increased during storage, whereas p-Avs remained level. When polyunsaturation level of the omega-3 oil incorporated into the spreads was higher, lipid hydroperoxides were unaffected and p-Avs increased. C:F (95:5) and C:F (85:15) spreads had the highest G′ values (P < 0.05), followed by the control spread (no ω-3 oil). Texture analysis showed that C:F (95:5) spread was the hardest (P > 0.05) and C spread (no β-carotene) was the softest (P < 0.05). Omega-3 oils had better oxidative stability when incorporated into double emulsion systems. Camelina spread and spreads containing blends of 15:85 or 5:95 fish oil with camelina oil, maintained adequate sensory acceptability for 8 weeks storage at 5 °C.