Physicochemical, structural characterization and evaluation of encapsulated hesperidin from natural sources: Comparison of two encapsulation techniques; spray drying and freeze drying

Freeze drying and spray drying techniques were evaluated for encapsulation of pure hesperidin and hesperidin from citrus peel extract in Maltodextrin and Gum Arabic in order to improve hesperidin stability and solubility. Physicochemical and structural properties of the microcapsules were determined and compared with the standardized high-purity hesperidin. Solubility of obtained microcapsules, defined by high WAI (0.202-0.697 g/g), WSI (88.02-99.746 %) and OAI (2.174-4.56 g/g), caused mainly by the amorphization of hesperidin structure was significantly improved. It was also confirmed with PXRD analyses. Microcapsules were of light colour, characterized by colour changes in the range from 12.57 to 47.49 and high whiteness index (64.12-94.45). The beneficial effect of encapsulation techniques is evident in flow properties where the Hausner ratio was in the range of 1.023-1.304 and Carr's index in the range of 2.26-23.273 %. Obtained microcapsules had satisfying hesperidin retention with encapsulation efficiency from 7.56 to 65.29 % and thermal stability above 110 degrees C. The best results were obtained for pure hesperidin encapsulated with freeze drying, satisfying results were obtained for citrus peel extract encapsulated in maltodextrin using spray drying. Obtained results indicate that the encapsulation of hesperidin can protect its bioactivities from environmental conditions and improve its solubility and flow properties, hence increasing its functional capabilities as pharmaceutical and cosmetic ingredients or additives.