Encapsulamento de extratos de própolis por secagem por atomização e estudos de libertação controlada

Mestrado em Engenharia Alimentar - Instituto Superior de AgronomiaPropolis is known for its bioactive properties, however, it presents sensory characteristics that limit its direct incorporation in food products. In this study, the potential of the microencapsulation of propolis was studied, in order to mask its unpleasant flavor, while maintaining its bioactive properties such as the antioxidant activity. The encapsulation process was carried by spray-drying using different materials: chitosan, chitosan with citric acid, chitosan with tripolyphosphate, rice starch and rice starch with gelatin. In terms of total phenolic compounds, the loading of the particles ranged between 0.049 and 0.062 mg EAG/mg particles, being a higher concentration when compared to the propolis itself (0.023 mg EAG/mg propolis). The release profile of propolis from the particles was studied by monitoring the concentration of total phenolics in acidic and neutral media. The percentage of total phenolics released in neutral solution was approximately 100% for all particles. In acid medium, the particles presenting a lower release of phenolics were chitosan with tripolyphosphate (27%), followed by chitosan with citric acid (39 %), rice starch with gelatin (46%), rice starch (52%) and chitosan (100%). The observed different release profiles allow us to infer that it is possible to design suitable particles for diverse end-use application