Microencapsulation of sweet orange oil terpeneless using the orifice method Original Research Article

This study used molecular distillation to remove terpenes (mainly limonene) from sweet orange oil and prepared microcapsules encapsulating sweet orange oil terpeneless by the orifice method. The morphology and microstructure of the microcapsules under the optimum conditions by orthogonal experiments were observed and the data of release kinetics were plotted according to the three different kinetic models to further investigate the release mechanism for microcapsules at different oven temperatures. The results showed that the limonene content was extremely low at a roller rate of 500–600 rpm, a feed flow rate of 20–30 mL/min, an evaporating temperature of 120 °C and an operating pressure of 0.025 mbar during molecular distillation. Encapsulation efficiency (EE) of microcapsules with good morphology and microstructure reached 87.34% when the CaCl2 concentration, sodium alginate concentration and ratio of wall material to core material were 2.0%, 2.5% and 5:1 respectively. The release profile of sweet orange oil terpeneless from the microcapsules could be well described by Higuchi equation.