Influence of polysaccharides on the physicochemical properties of lactoferrin-polyphenol conjugates coated β-carotene emulsions

This study investigated the influence of soybean soluble polysaccharides (SSPS) and beet pectin (BP) on the physicochemical properties of lactoferrin polyphenol conjugates coated beta-carotene oil-in-water (O/W) emulsions. beta-Carotene emulsions prepared using the layer-by-layer electrostatic deposition method had different interfacial compositions: (i) primary emulsions (lactoferrin (LF) or LF-chlorogenic acid (CA)/(-)-epigallocatechin-3-gallate (EGCG) conjugates); (ii) secondary emulsions (LF-CA/EGCG-BP/SSPS). The physicochemical properties of beta-carotene emulsions were evaluated by droplet size, zeta-potential, rheological behavior, transmission profiles using LUMiSizer and degradation of beta-carotene in the emulsions during storage. At pH 3.0, droplet sizes were in the range of 250.0-306.3 nm for the primary emulsions, and 304.5-466.6 nm for the secondary emulsions. The zeta-potential values of the secondary emulsions were significantly (p < 0.05) decreased than those of the primary emulsions. The droplet characteristics of the beta-carotene emulsions were considerably dependent on the interfacial compositions and pH. Compared with the primary emulsions, the secondary emulsions were highly stable at pH 3.0-9.0, which was attributed to the relatively thick biopolymer layer surrounding the oil droplets. The best physical stability occurred in the LF-EGCG-BP coated emulsion. In addition, the secondary emulsions stabilized by SSPS and BP could effectively inhibit the deterioration of beta-carotene in O/W emulsions. (C) 2015 Elsevier Ltd. All rights reserved.