Sugar beet pectin as a natural carrier for curcumin, a water-insoluble bioactive for food and beverage enrichment: Formation and characterization

Food and beverages enrichment with water-insoluble health-promoting nutraceuticals is important, but technologically challenging. Sugar beet pectin (SBP) is a natural dietary fiber with high emulsifying capacity. However, its potential as a natural encapsulator of hydrophobic nutraceuticals for beverage enrichment, has hardly been explored. Curcumin is a potent antioxidant with numerous attributed health benefits, but very low aqueous-solubility. We herein explored SBP as a carrier for solubilization and protection of curcumin (CUR). Using spectrofluorimetry, the CUR-SBP binding constant determined was (6.74 +/- 0.5) . 10(5)M(-1). As CUR:SBP molar ratio increased from 14:1 to 140:1, CUR encapsulation capacity increased from 14.5 +/- 0.8 to 127.4 +/- 0.4 mg(CUR/g SBP), and encapsulation efficiency moderately decreased from similar to 100% to 86 +/- 7%. The encapsulation in SBP dramatically decreased CUR particle size, from >17 mu m to <0.5 mu m, in average, and conferred substantial protection to CUR during simulated shelf-life, decreasing the decay rate constant similar to 7 fold. Therefore, SBP is a potent natural encapsulator for hydrophobic nutraceuticals for food and even clear beverage enrichment.