Influence of dextrose equivalent and storage temperature on food-grade rice bran oil-in-water Pickering emulsion stabilized by rice maltodextrins and sodium caseinate

Abstract

The application of Pickering emulsions is a common trend in the food, cosmetic and pharmaceutical industry. Among biopolymers stabilizing Pickering emulsion, rice maltodextrins (RMD) are considered as the most potential material due to their convenience, non-toxicity and the affordable cost. This study, therefore, combined rice maltodextrins producing by the α-amylase (of Aspergillus oryzae) with sodium caseinate to formulate Pickering rice bran oil-in-water (RBO/W) emulsions. The effect of various rice maltodextrins (with dextrose equivalent of 5.4, 7.6, 11.0, 12.8, and 14.5) on the physicochemical properties and the stability of those Pickering emulsions in the storage (at 30 °C and 4 °C) was investigated using various techniques including scanning electron microscopy, polarized light microscopy, dynamic light scattering, rheology and texture analysis. The results showed that emulsions stabilized by RMD with a dextrose equivalent of 12.8 had the highest stability. These colloidal dispersions are the shear thinning fluids and their viscosities strongly depend on RMD concentrations. When lowering the storage temperature from 30 °C to 4 °C, both the gel strength and the consistency of RBO/W emulsions were significantly improved and contributed into limiting the coalescence and the phase separation during storage.

Graphical Abstract

Keywords:

• Rice maltodextrin
• dextrose equivalent
• sodium caseinate
• rheology
• storage condition
• Pickering emulsions

Acknowledgment

The authors would like to acknowledge Nong Lam University – Ho Chi Minh City for providing financial support to the research.

Disclosure statement

The authors declare no conflict of interest.