beta-carotene and curdlan

A biopolymer-polyphenol conjugate-stabilized oil-in-water emulsion system was established to improve the chemical stability and bioaccessibility of β-carotene (BC). In this study, the emulsifying properties and contribution of a ferulic acid-grafted curdlan conjugate (Cur-D-g-FA) to the chemical stability of BC were investigated. Results showed that the emulsification ability of emulsions stabilized by Cur-D-g-FA remarkably increased with an increasing concentration from 0.05% to 0.8% (w/v) along with decreasing average droplet sizes, negatively charged zeta potentials, and uniform size distributions. The emulsions stabilized by 0.8% Cur-D-g-FA exhibited pronounced shear thinning and solid-like elastic properties as well as satisfactory oxidation stability. The emulsions stabilized by 0.8% Cur-D-g-FA had excellent ability to improve the chemical stability of BC when exposed to different environmental stresses and resulted in the favorable bioaccessibility of BC in vitro. The results prove that Cur-D-g-FA as a promising stabilizer has great potential to protect liposoluble nutrients in food-grade emulsion-delivery systems.

Topics: beta Carotene; beta-Glucans; Biological Availability; Corn Oil; Coumaric Acids; Emulsifying Agents; Emulsions; Food Storage; Hydrogen-Ion Concentration; Osmolar Concentration; Oxidation-Reduction

Grafting copolymerization of phenolic acids onto polysaccharides is an important strategy to improve their biological activities. In this study, ferulic acid (FA)-grafted carboxylic curdlan conjugates, namely, Cur-8-g-FA, Cur-24-g-FA, and Cur-48-g-FA, were synthesized by free radical-induced grafting. Results showed that FA was covalently grafted onto carboxylic curdlans via ester bonds. The grafting ratios of Cur-8-g-FA, Cur-24-g-FA, and Cur-48-g-FA were 223.03 ± 12.63, 115.63 ± 5.96, and 152.30 ± 4.57 mg FA/g, respectively, which were related with the carboxylate contents, molecular weights, and chain conformations of carboxylic curdlans. Compared with carboxylic curdlans, the FA-grafted carboxylic curdlan conjugates had lower thermal stability, molecular weight, and rheological property and looser surface morphology but had more prominent antioxidant benefits in vitro, which were proportional to their grafting ratios. Moreover, good storage stability against chemical degradation was exhibited by the β-carotene in Pickering emulsions stabilized by Cur-8-g-FA with a high grafting ratio and molecular weight.

Topics: Antioxidants; beta Carotene; beta-Glucans; Carboxylic Acids; Coumaric Acids; Emulsions; Free Radicals; Hydroxybenzoates; Molecular Weight