Stability of Capsicum annuum oleoresin-in-water emulsions containing Prosopis and Acacia gums

TLDR: In this paper, mesquite gum was the best emulsifying and stabilizing agent, followed by gum arabic and acacia gum, in all cases, pH had a dramatic effect on the emulsion stability against droplet coalescence and color degradation.

Abstract: Chilli oleoresin-in-water emulsions were stabilized with very low concentrations of mesquite (Prosopis juliflora), arabic (Acacia Senegal) and acacia (Acacia spp.) gums at different pH values in order to establish which polysaccharide had the best emulsifying capacity and provided the best stability against droplet coalescence and pigment degradation. Mesquite gum was the best emulsifying and stabilizing agent, followed by gum arabic and acacia gum. In all cases, pH had a dramatic effect on the emulsion stability against droplet coalescence and color degradation. The stabilizing mechanisms governing these two deteriorative processes were opposite. While coalescence kinetics was hindered at high pH values, color degradation kinetics took place at a higher rate, while the opposite effect occurred at lower pH values. A number of factors were important in determining the emulsifying capacity, the droplet coalescence stability and the color degradation stability of the gums among them, the protein content, the molecular weight, the surface charge and the steric configuration adopted at different pH values.