Proceedings of International Congress on Bioactive Compounds and International Workshop on Bioactive Compounds
Proceedings of 2nd International Congress on Bioactive Compounds

Propolis is a complex natural resin produced by worker bees. A new type of propolis was identified in the Northeast region and it was classified as Brazilian red propolis. Such material is of great commercial interest, however, for its application in food, the presence of alcohol is undesirable, as well as very striking sensory characteristics. In this context, the aim of this work was to produce propolis in powder form by spray drying, spray chilling and the association of both techniques of microencapsulation (for production of coated particles), to characterize the particles, to evaluate the antioxidant capacity and to study the formononetin (a chemical marker of the red propolis) release under simulated gastrointestinal conditions. The propolis extract was produced using ethanol (80% v/v). The powders produced by both techniques and their association were evaluated for moisture content, water activity, hygroscopicity, solubility, morphology by scanning electron microscopy, antioxidant capacity by ABTS and FRAP and the profile of formononetin release by in vitro simulated digestion assay. All powders produced were microbiologically stable, with low moisture content and water activity (aw < 0,60). The powders obtained by the spray drying technique presented the highest values of hygroscopicity and dispersibility followed by the powders containing the coated particles and the powders containing the particles obtained by spray chilling were the ones that presented the lowest values among the evaluated treatments. The particles that showed the highest antioxidant activities both by the ABTS method and by the FRAP method were the particles with the highest proportion of extract in relation to their dry mass. Regarding to stability during storage time, it is possible to notice that the antioxidant activity remained constant for most treatments. The morphology showed that all particles presented a matrix type characteristic, with different formats between treatments and fractions of particles obtained by spray drying are not properly covered by the combination of techniques. The study of the release under simulated gastrointestinal conditions showed very different release profiles between the particles in the three analyzed phases (oral, gastric and intestinal), with the particles obtained by spray drying having the release of formononetin concentrated in the oral phase while the particles obtained by spray chilling showed concentrated release in the intestinal phase and the coated particles showed increasing release throughout the test with the maximum in the intestinal phase. In conclusion, the use of microencapsulation techniques by spray drying, spray chilling and their combination result in particles with characteristics, antioxidant activities and release profile of the encapsulated compounds very different from each other, which resulted in a range of possibles application in the food or pharmaceutical industry.