Effect of soluble dietary fibres from Bambara groundnut varieties on the stability of orange oil beverage emulsion

Abstract

Soluble dietary fibres (SDFs) [30% (w/w)] from four varieties of Bambara groundnut (BGN), viz. black-eye, brown-eye, brown and red were used to stabilize orange oil beverage emulsions at 6% (w/w) orange oil. Emulsion stability was studied using Turbiscan MA 2000 and in terms of oil-droplet size characterization. The volume-surface mean diameter (d_3,2) and equivalent volume-mean diameter (d_4,3) of the four emulsions ranged between 2.68–4.38 µm and 17.09–18.62 µm, respectively. Emulsions stabilized with black-eye-SDF and brown-SDF possessed the least and highest d_3,2 and d_4,3, respectively. The d_3,2 and d_4,3 of all four emulsions were significantly (p < 0.05) different. Emulsions were relatively stable to creaming and destabilized mainly by phenomenon involving oil-droplet aggregation. The backscattering flux of the emulsions ranged from 72.9% (brown-SDF stabilized emulsion) to 85.0% (black-eye-SDF stabilized emulsion). All four BGN SDFs greatly indicated their potential in stabilizing beverage emulsions.