Optimization of microencapsulation of fish oil in the coating of sodium caseinate, maltodextrin, whey protein concentrates and modified starch by mixture design method

The present research was done with the aim of encapsulation of fish oil with a ratio of 3:1 (oil: coating) with coatings of maltodextrin, sodium caseinate, whey protein concentrate and modified starch with different ratios by freeze dryer and in order to achieve the maximum encapsulation efficiency was optimized using a mixture design. Optimizing the concentration of different walls for microencapsulation using numerical and graphical optimization revealed that the optimal wall composition contains maltodextrin (15.16%), sodium caseinate (20%), whey protein concentrate (20%) and modified starch (19.84 %) with the encapsulation efficiency was 89.3 %.The results showed that according to the difference in the wall compositions and their ratios, the particle size, poly dispersity index (PDI), and encapsulation efficiency had different values. So that the size of the particles varied from 0.34 μm to 1.3 μm, and the PDI varied from 0.1 to 0.92. Evaluation of oxidative stability in optimal microcapsule powder and free fish oil stored at 0 and 32% humidity during 21 days of storage showed that encapsulated oil at zero humidity had higher oxidative stability during the storage period. In addition, the increase in humidity in the storage environment of microcapsules increased the intensity of oxidation in the treatments stored in 32% humidity. Therefore, it can be concluded that the use of microencapsulation technique is a practical and effective method to increase the oxidative stability of fish oil for use in the food and drug industry.