Tapioca maltodextrin fatty acid ester as a potential stabilizer for Tween 80-stabilized oil-in-water emulsions

The esterified maltodextrins were prepared by enzymatic esterification of matodextrin with dextrose equivalent (DE) of 16 (DE16) and 9 (DE9) and three fatty acids: decanoic acid (C-10), lauric acid (C-12) and palmitic acid (C-16) at reaction condition of 60 degrees C for 4 h. The microstructure of emulsions stabilized by 5% and 35% (w/w) esterified maltodextrin DE16 palmitate were evaluated. The added esterified maltodextrin palmitate was adsorbed on the surface of the oil droplets. The critical flocculation concentration (CFC) of Tween 80-stabilized emulsions containing esterified maltodextrin DE16 and DE9 were 19% and 14% (w/w), respectively, as revealed by a microscopic method. Esterified maltodextrin extended the CFC of emulsions compared with native maltodextrin, with the CFC of Tween 80-stabilized emulsions containing native maltodextrin being 11% (w/w) for maltodextrin DE16 and 6% (w/w) for maltodextrin DE9. At esterified maltodextrin concentrations below the CFC, no creaming or flocculation were observed and the flow of the emulsions exhibited Newtonian behavior at these concentrations. At concentrations above the CFC, the emulsions containing esterified maltodextrin showed extensive flocculation of emulsion droplets that resulted in very low creaming stability and consequently, the expression of shear-thinning flow behavior. Further increases in the concentration of esterified maltodextrin improved the creaming stability. Esterified maltodextrin was more effective in preventing creaming compared with native maltodextrin. The extent of the flocculation of emulsions decreased at high concentrations of maltodextrin DE9 palmitate. (C) 2014 Elsevier Ltd. All rights reserved.