Microencapsulation by Complex Coacervation Using Whey Protein Isolates and Gum Acacia: An Approach to Preserve the Functionality and Controlled Release of beta-Carotene

摘要

beta-Carotene is a red-orange pigment, a known source of vitamin A and has exceptional antioxidant and free radical scavenging potential. However, uses of beta-carotene in food industry are inadequate mostly because of their poor water solubility and low stability. Using the complex coacervation technique, the work is meant to fabricate the microcapsules of beta-carotene, to examine the physicochemical properties of microcapsules and finally to evaluate the extent of stability improvement. The configuration of electrostatic complexes between whey protein isolate (WPI) and gum acacia (Acacia arabica, GA) was optimized as a function of pH, ionic strength, WPI/GA ratio, core material load and size of final micromolecules. The optimum process conditions were balanced by the ratio of wall materials WPI/GA 2.0/1.0 % and pH value 4.2. Morphological observations showed that microcapsules presented spherical shape, and smooth and continuous surface. The effective amount of encapsulated core was greater than 70 % for all formulations evaluated. In vitro release data indicated an initial burst release followed by sustained release behavior. The microstructure and viscoelastic properties of WPI and GA complex were studied using dynamic rheometer. The encapsulation method and the wall materials used in this work gave effective protection during storage and eventually resulted sustained release of bioactive while used in food matrix, at suitable conditions.