Emprego de polissacarídeos alginato de sódio e gelatina no processo de encapsulamento e cinética de liberação de óleo de alho

Abstract

Microencapsulation is a widely used technique which consists on the enclosing of substances by a material which covers and protects these substances from environmental conditions, while also allowing a controlled release of active agents. Microcapsules can be obtained through many methods, with the use of polysaccharides, in order to form the polymeric matrix, which will encapsulate the active agent. This work aimed the production of microcapsules from sodium alginate and gelatin polysaccharides in order to control the release of garlic oil. Ionic gelation, a method which is based on the extrusion and dripping in a calcium chloride solution, was employed. The following techniques were utilized in order to characterize the material: scanning electron microscopy, energy dispersive x-ray spectroscopy, Fourier-transform infrared spectroscopy and thermogravimetric analysis. Moisture content, intumescence level and microcapsules’ yield were determined as well. Finally, garlic oil release kinetics in acidic environment (in order to simulate the gastrointestinal system) was studied. The results showed that the microcapsules’ moisture content were of 88,62% and 90,63% and had a microencapsulation yield of 41,72% and 57,63%. The microcapsules with an incorporated crosslinker (tannic acid) in its formulation showed less intumescence when compared to the ones with no crosslinker. The produced microcapsules showed thermal stability and efficiency on the controlled release of garlic oil. Therefore, microencapsulation was effective to produce a material with good thermal and structural properties as well as a good controlled release of garlic oil.