Microencapsulation Of Fish Oil And Oxidation Control Technology

The microencapsulation of fish oil was prepared by spray drying and complex coacervation. The influences of different wall materials and process parameters on the content of surface oil, particle size of emulsion, peroxide value of fish oil were discussed in this paper. Effects of single and combined antioxidant on peroxide value, propanal value and morphological variation of powdered fish oil during storage were investigated. The stability and oxidation resistance of the microencapsulated fish oil were evaluated during storage.1. Five wall materials were applied to microencapsulation of fish oil by complex coacervation. Based on the content surface oil, encapsulation efficiency and oil loading, the mixed wall material of gelatin and gum arabic were more suitable. The optimal parameters were as follows:pH4.0,1:1of the ratio of gelatin to gum arabic,2%of colloid concentration,1:2of the ratio of core to wall. The retention rate of EPA and DHA after oil powered was97.03%and96.28%.2.The optimal mixed wall material of n-octenylsuccinate-derivatized starch (CO01) and glucose syrup was selected for microencapsulation of fish oil by spray drying. Effects of homogenization pressure on emulsion viscosity, particle size and particle size distribution were studied. The influence of inlet/outlet drying air temperature on microencapsulation efficiency and peroxide value (POV) of fish oil was discussed. The results showed that the emulsion viscosity and average particle decreased with the increasing of homogenization pressure, while the particle size distribution showed a downward trend in general. The particle size distribution reached the minimum values in400bar, while the uniformity of the particle size was the best. The optimal process parameters were as follows:400bar of homogenization pressure,140℃/70℃of inlet/outlet air temperature of spray drying. Under the above process conditions, the emulsion particle had9.64μm of average size,2.03%of the surface oil content and95.6%of the microencapsulation efficiency. The scanning electron microscopy analysis also showed that powered fish oil had better surface and inside structures.3.The antioxidation of natural antioxidant was evaluated in preparation of powered fish oil. The optimal amount of antioxidant was1100mg/kg of vitamin E,500mg/kg of ascorbyl palmitate and1200mg/kg of rosmary. Under these conditions, the active ingredients of fish oil (EPA and DHA) were effectively protected, and could be stored at room temperature for60days. The retention rate of EPA and DHA was 97.60%, increased by2.6%when comparing to the fish oil microencapsulation without adding antioxidant.