Microencapsulation of gamma oryzanol using inulin as wall material by spray drying: optimization of formulation and characterization of microcapsules

Gamma oryzanol (GO) is the rice bioactive compound which presents various therapeutic effects. However, GO is relatively unstable to environmental factors during processing and storage. The objective of this work was to produce GO microparticles encapsulated with inulin and Tween80 (GOINs) by spray-drying. Response surface analysis was used for the optimization of the encapsulation to get maximum % encapsulation efficiency (%EE) of GO. Three process variables for the concentration of 10–20% inulin (w/v), 3–5% Tween 80 (w/v), and 3–5% GO (w/v) were investigated. Quadratic polynomial regression model for the optimization with R² at 0.92 was obtained from the study The optimum condition was 20% inulin (w/v), 3% Tween 80 (w/v), and 3% GO (w/v) which yielded a high % EE of 82.63% and particles size at 1,154.60 ± 28.85 nm Fourier transform infrared spectroscopy demonstrated that GO was encapsulated inside the inulin matrix. Our study provided potential and improved hygroscopicity ranged from 6.51 to 10.22 g H₂O/100 g dry weight of GO in spray-dried microcapsules.