Response Surface Methodology: An Optimization of Process Variables for the Nanoencapsulation of Anthocyanins from Black Rice Bran

Abstract

Nanoencapsulation technology has been used in food and pharmaceutical applications to increase bioactive chemical functioning and stability against external influences. To develop a cost-effective encapsulating procedure, additional optimization is required. This study employed response surface methodology (RSM) to optimize the encapsulation of anthocyanin-rich extract from black rice bran. The extract was encapsulated through pre-gelation and polyelectrolyte complex formation processes. Box-Behnken design was employed to determine the optimum conditions for the encapsulation process with the following process variables: chitosan concentration, pH, and CaCl2 concentration. Chemical characteristics, surface morphology, and particle size were used to describe the resultant capsules, which were then subjected to phytochemical analysis. The optimal encapsulation conditions for anthocyanin were 6.30 mg/mL chitosan, pH 5.5, and 36 mM CaCl2, with a 51.20 % encapsulation efficiency. The developed anthocyanin-loaded nanocapsule has a high TPC (3.87 mg GAE/g) and potent antioxidant activity (5.69 mg TE/g). SEM images revealed a smooth surface area and spherical particles that clumped together, with an average particle size of 94.70 nm. FTIR analysis corroborates the well-incorporation of anthocyanin into the nanocapsules. The encapsulation process of anthocyanin-rich extract from black rice bran was successfully optimized via RSM.