Optimisation and characterization of double emulsion derived from rice starch, rice protein isolates and rice bran oil

Abstract

This study focused on the development and evaluation of a stable emulsion system using rice starch, protein isolates, and bran oil as food ingredients. This was performed using a one-factor-at-a-time (OFAT) experimental strategy, which was subsequently refined using response surface modeling (RSM), and the emulsion was then characterized. The resulting quadratic polynomial model effectively captured all the responses, with regression coefficients exceeding 0.90. The emulsion activity index, emulsion stability index, and droplet size were 86.29 %, 93.44 %, and 100.59 nm, respectively. Turbidity was significantly influenced by particle size, with the double emulsion (sample B) exhibiting higher turbidity index (43,250.34 ± 0.046) than the reference sample (29,433.303 ± 0.018). The viscosity of the emulsion increased with the addition of the protein isolates. This inferred that a stable emulsion system derived from rice could serve a multifunctional purpose as carriers, fillers, and binders to enhance the physical, functional and sensory properties of foods.