The correlation of wall material composition with flow characteristics and encapsulation behavior of fish oil emulsion

The objective of this study was to examine the effect of wall material composition and the presence of tween 20 in emulsion formula on fish oil microcapsule properties produced by spray drying. A total of 4 wall materials including skim milk powder (SMP), 70% SMP + 30% maltodextrin, 70% SMP + 30% lactose, 70% SMP + 30% sucrose, and all of these wall materials with 1 g tween/100 g fish oil were used for emulsion preparation. The prepared emulsions were characterized with respect to droplet size, surface tension, viscosity, and viscoelastic properties. The emulsions were dried in mini-spray dryer at drying air temperature of 175 °C. Results showed that tween significantly influenced the properties of emulsion and slightly but not statistically significant increased the encapsulation efficiency. The microcapsules produced by 70% SMP + 30% lactose and 70% SMP + 30% sucrose were selected as the best microcapsules according to high encapsulation efficiency and acceptable level of peroxide value. Differential scanning calorimetry (DSC) and Fourier‐transformed infrared (FT‐IR) analyses of these microcapsules revealed no chemical interaction between fish oil and wall material in the structure of capsules.

► Significant effect of Tween 20 on emulsion properties. ► Positive effect of lactose and sucrose on encapsulation efficiency. ► Little effect of Tween 20 on properties of finished product. ► No chemical interaction between wall material and fish oil.