Improving probiotic survival using water-in-oil-in-water (W/O/W) emulsions: Role of fish oil in inner phase and sodium alginate in outer phase.

Aqueous probiotic suspensions were dispersed in an oil phase consisting of fish oil and medium chain triglycerides to form W/O emulsions. These emulsions were then homogenized with an aqueous solution containing soybean protein isolate and sodium alginate to form W/O/W emulsions. Fish oil was used to promote the growth of the probiotics and increase their ability to adhere to the intestinal mucosa. Sodium alginate increased the viscosity, stability, and probiotic encapsulation efficiency of the double emulsions, which was mainly attributed to its interactions with adsorbed soy proteins. The encapsulation efficiency of the probiotics in the double emulsions was relatively high (>96%). In vitro simulated digestion experiments showed that the double emulsions significantly increased the number of viable probiotics remaining after passing through the entire gastrointestinal tract. This study suggests that encapsulation of probiotics in double emulsions may increase their viability under gastrointestinal conditions, thereby enhancing their efficacy in functional foods.