Emulsifying property of Schinopsis brasiliensis gum in oil-in-water emulsions

Gums are polysaccharide compounds widely used by food, pharmaceutical and biomedical industries for different purposes, in particular due to their ability to stabilize emulsions. In this work, the raw gum of Schinopsis brasiliensis Engl., popularly known as Barauna (GB) was employed in different oil/water formulations in order to evaluate its emulsifying activity in comparison with the commercial Arabic gum (GA) as a positive control. Rheological properties of GB and GA were also evaluated and similar behavior was observed. To study the emulsifying activity of each sample, a three-stage experimental design combined with a 24 full factorial design was developed. At each stage, parameters such as sample concentration, oil concentration, agitation speed and agitation time were recorded. The evaluation of the physical-chemical properties of the emulsions indicated that the stirring speed and oil concentration were the variables that most influenced the stability of emulsions. Regardless of the type of the gum, the emulsions prepared with the highest agitation speed (25000 rpm) and lowest oil concentration (1.0%v/v), in general, showed smaller droplet size and polydispersity index (PDI), and, therefore, greater stability. Emulsions prepared with GB (4.0 mg/mL) were stable for a longer period of time (28 days) than those obtained with GA. These results suggest that the optimization of the speed and time of agitation for the samples preparation containing GB could result in emulsions with the highest potential to achieve the ultrafine (nano) dimensions required for pharmaceutical, medical and food industry applications. [Display omitted] •Gums are extensively used as thickeners and stabilizers in the food industry.•Discovering new sources of gum can reduce the external dependence on commercial Arabic gum.•The Brazilian Caatiga biome is a source of new polymers with emulsifier properties.•Baraúna gum showed composition, rheological behavior and emulsifier properties similar to arabic gum.