Facile microencapsulation of olive oil in porous starch granules: Fabrication, characterization, and oxidative stability

In this study, starch with porous structures derived from purple sweet potato was prepared and used as a food-grade polymer for the microencapsulation of olive oil. The optimal reaction conditions for preparing porous starch were determined to improve its adsorption capacity as effective microcapsule-wall materials. Olive oil was then impregnated in microspheres, and loading ratio was optimized by investigating the restrictive factors, including the mass ratio of olive oil to porous starch, as well as the embedding temperature and time. The presence of olive oil in the starch matrix was confirmed by SEM, FTIR, and TGA. Results demonstrated that the porous starch-based microencapsulation exhibit a stable olive oil loading ratio and a significant improvement in oxidative stability compared with free olive oil. The newly-proposed process used in this work was easy to scale up for developing a new and attractive method for oil protection in the food industry.