Improvement of vitamin E microencapsulation and release using different biopolymers as encapsulating agents

• Vitamin E microparticles were produced by spray-drying using several wall materials. • The final particles were characterised by size, morphology and kinetic behaviour. • Mathematical models were adjusted to the release profiles. • The product yield and encapsulation efficiency were calculated. • Vitamin E was efficiently protected and can now be applied in functional products. Vitamin E is a fat-soluble vitamin that, due to its exceptional therapeutic properties, has been the focus of several research fields. However, when exposed to adverse environmental conditions, this compound degrades, which makes its direct consumption or application into functional products impossible. In this context, techniques like microencapsulation emerged, being spray-drying one of the most widely used encapsulation techniques, due to its economical, flexible and continuous operation process and to the well stablished and readily available equipment. During the current work, vitamin E was encapsulated by spray-drying, using different biopolymers as wall materials, in order to evaluate which formulation would lead to the most suitable results. Particles with sizes between 4.3 and 25.1 μm and surface structures with more or less pronounced wrinkles were obtained, depending on the encapsulating agent used. These vitamin E particles were produced with a product yield between 15 and 55%, and with an efficiency of encapsulation that ranged between 70.1 and 99.4%. The release results revealed that, if the final application of the particles requires a fast release, formulations of vitamin E with sodium alginate, inulin and maltodextrin should be applied. On the other hand, the use of wall materials like Arabic gum, modified chitosan, starch and modified starch, will lead to long vitamin E release times, which is the most suitable option when slow and continuous releases are desired. All the results obtained proved that vitamin E could be efficiently protected through the encapsulation by spray-drying, with microparticles with different morphologies, sizes and release behaviours according to the encapsulating agent used in the initial formulations.