Investigating the interfacial and bulk rheological properties of emulsions containing dry bean powder

Abstract

This study aimed to investigate the impact of varying proportions of dry bean powder on the rheological properties of oil-in-water emulsions. Emulsions were formulated utilizing xanthan gum or dry bean powder across a range of concentrations, including 1%, 3%, 5%, and 7%. Additionally, a control emulsion (CTR) was formulated using xanthan gum exclusively. The rheological properties of the resulting emulsions, both linear and nonlinear, were characterized. Moreover, the correlation between microstructural attributes and the interfacial rheological response within these emulsion systems was thoroughly examined. A prominent observation was the occurrence of shear thinning, characterized by a reduction in viscosity under applied shear stress. Notably, the control emulsion (CTR) displayed the lowest interfacial viscosity values, whereas emulsions incorporating increasing proportions of dry bean powder demonstrated a proportional rise in interfacial viscosity. The highest consistency coefficient and apparent viscosity was recorded in the 7%DB sample with a value of 3.23 Pa.sn and 0.56 Pa.s, respectively. This suggests that emulsions formulated with dry bean powder may yield a more resilient interfacial film, attributed to the protein content inherent in dry beans. The establishment of a viscoelastic interfacial layer facilitated by dry bean powder in appropriate concentrations significantly contributes to the long-term stability of the emulsion. Unraveling the intricate relationship between interfacial behaviors holds paramount importance in advocating for the utilization of dry bean powder as a plant-based protein source. In conclusion, the incorporation of dry bean powder enhances the formation of interfacial films in O/W emulsions.