Development and characterization of double emulsion to encapsulate iron

In this study, it was aimed to prepare and characterize double (W-1/O/W-2) emulsions for encapsulation of ferric chloride within the internal aqueous phase (W-1). The primary (W-1/O) emulsion to be used in double emulsion was examined for oxidative stability and whey protein isolate was found effective in improving oxidation stability. The double emulsions were prepared with different primary emulsion:external water phase (W-1/O/W-2) ratios as 40:60, 30:70 and 20:80; the emulsions were characterized in terms of droplet size, encapsulation efficiency, rheology, creaming stability and in vitro iron bioaccessibility. The emulsion with 40:60 ratio had the highest viscosity and encapsulation efficiency whereas it had the lowest creaming index and droplet size. It was also obtained that iron bioaccessibility increased as the ratio of W-2 phase increased and the double emulsion with 20:80 ratio showed the highest bioaccessibility (52.97 +/- 0.89%). This study may enable the use of double emulsion encapsulation in the enrichment of food products with iron.