A novel method for drop in drop edible oils encapsulation with chitosan using a coaxial technique

The presented work concerns a novel one step method for oil encapsulation. In this coaxial system the oil constitutes the core of the capsule, while the chitosan solution is the polymer shell surrounding the core to provide separation of the core from the external environment. The paper contains a diagram of the encapsulation equipment and explains the principle of its operation. The experimental results showed the impact of the media flow rate on the size, shape, mechanical properties and the amount of oil in the capsules. Conditions of the core solution were determined to be: 2.00 g/h, and shell solution: 4.45 g/h. Maximal oil content obtained under these conditions was: 45.2%. The diameters of the capsules collected gravitationally in the nitrogen stream were from 3.7 to 4.4 mm and from 2.8 to 4.3 mm, respectively. The force needed to obtain 50% compression strain of all tested samples was in the range from 0.11 to 0.19 N. In comparison to other encapsulation methods, the presented technique is much simpler and can be performed under mild conditions. Moreover, the use of natural polymers as a coating matrix enables the use of the described technique in many branches of industry.