Microwave-Assisted Extraction (MAE) of Rice Bran Protein as a Wall Material for γ-Oryzanol Encapsulation

Rice bran contains various bioactive compounds, including γ-oryzanol, which can reduce hypercholesterolemia. However, the reactivity of γ-oryzanol in the environment results in the need for encapsulation to maximize the use of bioactive compounds. Many encapsulation processes have been developed using wall material from many resources. Rice bran, which also contains rice bran protein (RBP), has hypoallergenic properties, good foaming stability, and can be used as a wall material. Therefore, this work focused on enhancing protein extraction from defatted rice bran (DRB) by microwave-assisted extraction (MAE) to produce RBP suitable for encapsulating γ-oryzanol. RBP obtained by conventional alkaline extraction (CAE) revealed that the highest yield of RBP of 7.88% was obtained at T 60 °C, t 60 min., and pH 11. This operation condition was then used to optimize the extraction of RBP-MAE using power and time variables. The RBP-MAE is as high as 14.16%, almost double compared to RBP-CAE at power 100W, t 25 min., and pH 11. The solubility, foaming, and zeta potential of RBP revealed properties that make it a suitable wall material for γ- oryzanol encapsulation.