Color, moisture and microstructure characteristics of Omega 3 fatty acids Nano-capsules produced by application of Coaservation technique

In this study, nano-encapsulation offish oil Omega 3 fatty acids was optimized by using response surface methodology (RSM) in the central composite design (CCD). Omega-3 nano-particles,containing fish gelatin and Arabic gum as wall materials,were produced using coacervation technique. Based on the results of three independent variables as fish gelatin concentration (33-66%),the concentration of omega-3 (10-30%) and the homogenizer speed at three levels (10000, 15000 and 20000 rpm) on the dependent variables such as moisture, color parameters andmicrostructure, it was revealed that the homogenizer speed had the greatest impact on the particle size (p<0.05). Morphology of powders showed that the produced powders had a relatively smooth and brittle surface and porosity was observed in case of some samples.Furthermore, moisture content of nanocapsules which were dried by freeze drying was in the range of 4.2%-7.3%. The most important factors that influence the moisture was found to be the gelatin concentration, as by increasing the concentrations of fish gelatin, the moisture of nanocapsules increased. According to color indices, fish gelatin concentration had the greatest impact on the rate of Lightness (L*) of produced powders, as by increasing of fish gelatin concentrations, the lightness of nanocapsules decreased whereas the yellowness (b*) increased.