Double-layered emulsions as beverage clouding agents

摘要

There is a constant interest in finding alternatives to gum arabic in flavour and beverage industries. The ability to prepare beverage-cloud emulsions using a layer-by-layer deposition technique was developed with extremely low usage levels of proteins and polysaccharides. Sodium caseinate (S) and -lactoglobulin (L) were selected to stabilize the primary emulsions. Polysaccharides of sodium alginate (A), -carrageenan (C), gum arabic (G) and pectin (P) were evaluated as secondary layers. Polysaccharide concentration was optimized based on droplet size and -potential. The performance of double-layered emulsions in beverage-cloud applications was evaluated. Polysaccharide concentration and pH were found critical to the formation of stable multilayered emulsions. Protein and polysaccharide type also impacted droplet size and -potential of multilayered emulsions. -Lactoglobulin was found to be better than sodium caseinate in forming protein-polysaccharide interfacial complexes, as demonstrated by smaller mean droplet diameters (MDD) of L-A, L-P and L-C than those of S-A, S-P and S-C. It was also found that the polysaccharide concentration has to be above a critical value (0.2-0.5wt% depending on the type of polysaccharides) to prevent multilayered emulsions from bridging flocculation. Data showed that double-layered emulsions of L-A, L-C and L-G formed by electrostatic deposition could provide the same performance as traditional emulsifiers of gum arabic (G) and modified starch (M). After four weeks of storage at room temperature, beverage clouds stabilized with G, M, L-A, L-C and L-G showed MDDs of 0.68, 0.67, 0.90, 0.82 and 0.65 mu m, respectively, and turbidity losses of 18, 28, 22, 19 and 25%, respectively. Copyright (c) 2014 John Wiley & Sons, Ltd.