Formulation and Characterization of Gum Arabic Stabilized Red Rice Extract Nanoemulsion

Interest in the utilization of plant-based bioactive compounds in foods has increased due to their biochemical activities and as alternatives in the reduction of high concentrations of chemical utilization. However, some of these additives are hydrophobic, thus being harder to disperse into the hydrophilic food matrix. Therefore, an oil-in-water nanoemulsion (RRE1-RRE10) was formulated with different concentrations of red rice extract (1-10% w/v). Nanoemulsion showed droplet sizes within the range of 157.33-229.71 nm and the best formulation (RRE5) was selected based on the creaming index which was stable to flocculation over a range of temperatures (30-90 °C), pH (2-9), and salt concentration (100-600 mM). It showed significantly improved antioxidant and anti-inflammatory activity as compared to its other counterparts. Potential antimicrobial activity against Staphylococcus aureus was attributed to RRE5 nanoemulsion as compared to Escherichia coli. Therefore, due to the potential bioactivity of RRE5 nanoemulsion, it can be scaled up at the industrial level.