Abstract

The study reported here aims to obtain information on how thickener type and concentration, and oil content influence rheology, particle size, particle charge and microstructure in o/w model emulsions. Emulsions were prepared at two oil concentrations (5 and 30 % wt/wt), each with three CMC concentrations (0. 2, 0. 3, and 0. 4 % wt/wt), or three starch concentrations (2, 3, and 4 % wt/wt). For each oil concentration, a sample without any added thickener was prepared as reference. Both CMC and swollen starch granules showed a dominating effect on emulsion flow behavior, although the presence and concentration of fat droplets also played an important role. Viscoelasticity of CMC-based emulsions mainly depended of oil concentration whilst in starch-based emulsions the most influential ingredient was starch. A similar situation was detected in terms of particle size distribution; CMC effect was dependent on oil content and starch effect was mainly related to the volume occupied by swollen granules. Differences in microstructure and particle size distribution between CMC and starch emulsions were related to their rheological behavior. Apart from enabling the acquisition of food emulsions with different composition but with similar rheological behavior by adding different hydrocolloids, here we consider thickener effect on other properties in order to obtain food emulsions with adequate characteristics. © 2013 Springer Science+Business Media New York.