Curcumin, the principal curcuminoid of turmeric (Curcuma longa L.), has been largely studied due to its bioactive properties. The main problem involved in many curcumin applications is its poor water solubility. Encapsulation of curcumin by different techniques has also been largely studied to overcome this problem. The choice of which technique, type of encapsulating agent and other processing conditions are important to determine curcumin bioactivity, physical & chemical properties, as well as the proper applications. Another technique applied to surpass this problem is the wet milling, that allows the size reduction of water insoluble compounds. In the present work two strategies of curcumin encapsulation were investigated, the nanoprecipitation (zein as encapsulating agent) and the solid dispersion (polyvinylpyrrolidone (PVP) and poloxamer 407 as encapsulating agents). Also, the wet milling technique was used in order to produce curcumin microcrystals. The produced nanoparticles and microcrystals were compared in relation to their thermal properties (Differential Scanning Calorimetry) and curcumin-encapsulating agent chemical interactions (Fourier Transform Infrared Spectroscopy). The obtained materials were evaluated in relation to their antioxidant activity (TBARS assay), antimicrobial activity against Escherichia coli and Pseudomonas aeruginosa, cytotoxicity (SRB assay) in four human tumor cell lines: MCF-7 (breast adenocarcinoma), NCI-H460 (lung carcinoma), HepG2 (hepatocellular carcinoma), HeLa (cervical carcinoma) and in a non-tumor cell line, prepared from a freshly harvested porcine liver (PLP2). The physical & chemical characterization showed that curcumin presented amorphous structure into the nanoparticles, but microcrystal showed the same melting temperature that pure curcumin, indicating that micronization caused no appreciable change in melt properties. When encapsulated, the FTIR band located around 1510 cm-1, related to C=C bond of curcumin, is clearly supressed from spectra, independently of the encapsulation technique or encapsulating material, being a strong evidence that curcumin is mainly located into the particles, not dispersed superficially. Minimum Inhibitory Concentrations of curcumin microcrystals determined against Escherichia coli and Pseudomonas aeruginosa were 8 fold lower when compared to the nanoparticles of curcumin-PVP obtained by solid dispersion. In relation to TBARS assay, nanoparticles encapsulated by the same technique (solid dispersion) but using different encapsulating agents, resulted in a lower EC50 value for PVP (11 µg.mL-1) when compared to poloxamer 407 (17 µg.mL-1). Furthermore, the same nanoparticles showed higher cytotoxicity in human tumor cell lines, but presenting also toxicity for non tumor PLP2 cells (206 µg.mL-1). Finally, curcumin encapsulated in zein was applied as antimicrobial agent into an edible film forming solution (gelatin), where Benitaka grapes were dipped, to produce an active edible coating. The overall results showed that quality parameters, such as texture and titratable acidity, were not affected by the edible coating presence, and that the microbiological quality was maintained. Curcumin microcrystals were applied in minimally processed carrots, showing lower mesophilic, psychrophilic and coliforms counts. Discriminative and affective sensory tests showed that panellists did not differ curcumin treated samples from the control and that probably samples would be bought by consumers. Curcumin encapsulated in PVP was applied as colouring and bioactive agent into yogurt, showing good color stability during 15 days storage time.