Physicochemical and sensory properties of yogurt enriched with microencapsulated fish oil.

Encapsulation of marine omega-3 oil by complex coacervation technique has been introduced as most effective approach to delay its oxidation and extend shelf life of ω(3)-enriched food products. Therefore, to produce enriched yogurt, fish oil containing long-chain omega-3 polyunsaturated fatty acids was microencapsulated in complex coacervates of gelatin/acacia gum. Then, the microcapsules were dried and their surface oil was extracted. Set yogurt was prepared by enriched milk with microcapsules powder. Physicochemical and sensory properties of enriched yogurt were measured during 21 days storage. Acidity, apparent viscosity and water holding capacity of enriched samples were higher and gel strength and amount of whey separation were lower compared to the control. The enriched yogurt samples were more yellowish compared to control. The peroxide value of free and encapsulated fish oil in enriched yogurt samples, after 22 days storage, were increased to 72% and 260%, respectively. Fish oil release of microcapsules was not detected by gas chromatography in extracted oil from enriched yogurt. Sensory results showed that untrained panelists evaluated overall acceptance of enriched yogurt with treated-fish oil microcapsules by lime juice as 'neither liked nor disliked to slightly liked'.