Microencapsulation of oil and protein hydrolysate from fish within a high-pressure homogenized double emulsion

In this study, the effect of high-pressure homogenization on the water-in-oil-in-water (W₁/O/W₂) double emulsions containing fish protein hydrolysate and fish oil encapsulated within a complex of whey protein concentrate and inulin were investigated in order to produce stable double emulsion. After adequacy of the positive influence of high-pressure homogenization at W₁/O (one pass) and W₁/O/W₂ (three passes), the double emulsions were produced with (H) and without (HS) high-pressure homogenization. H samples were demonstrated lower CI of double emulsion and higher amounts of yield, total oil, encapsulated oil, EPA and DHA of microcapsules in comparison with HS samples. At subsequent step, response surface methodology were applied to optimize the high-pressure homogenization conditions (700-1500 Ba) of double emulsions in terms of minimum CI of emulsions and maximum microencapsulation efficiency and oxidation stability. Optimal conditions were obtained by using high-pressure homogenization at 1000 and 1100 Ba on W₁/O and W₁/O/W₂, respectively.