Microencapsulation of fish oil using supercritical antisolvent process

•The supercritical fluid technique uses the solute effect of supercritical carbon dioxide (SC-CO2) to precipitate the substrate initially dissolved in a polymer.•The use of supercritical fluids allows a precise control of the crystallization process and is capable of generating very small and uniform particles of fish oil.•Microencapsulation processes that exhibit a good solubility in CO2 have very promising applications due to the simplicity and immaculateness of the process.•The impact of inert heat transfer agents in terms of particle characteristics to measure the impact of different polymer on the final products to obtain microencapsulated form of the final product.•Green technology, i.e., organic residues free micron-sized particles can be obtained.

In order to improve the encapsulation process, a newly supercritical antisolvent process was developed to encapsulate fish oil using hydroxypropyl methyl cellulose as a polymer. Three factors, namely, temperature, pressure, and feed emulsion rate were optimized using response surface methodology. The suitability of the model for predicting the optimum response value was evaluated at the conditions of temperature at 60°C, pressure at 150 bar, and feed rate at 1.36 mL/min. At the optimum conditions, particle size of 58.35 μm was obtained. The surface morphology of the micronized fish oil was also evaluated using field emission scanning electron microscopy where it showed that particles formed spherical structures with no internal voids. Moreover, in vitro release of oil showed that there are significant differences of release percentage of oil between the formulations and the results proved that there was a significant decrease in the in vitro release of oil from the powder when the polymer concentration was high.

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