Abstract: Objective: Shellac resin ammonium salt (SRAS) was used to prepare the SRAS/resveratrol (RES) microcapsules with pH response and antioxidant activity in order to improve the bioavailability of RES. Methods: SRAS was used as wall material for RES microencapsulation by spraying drying, and the properties of SRAS/RES microcapsules were characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC), and antioxidant activities and release behaviors under different pH conditions were studied as well. Results: The microencapsulation efficiency was 82.70%, and the load rate was 8.27% when 2 g of SRAS, 0.278 g of RES and 0.5 g of Tween 80 were used in the formulation. SRAS/RES microcapsules were microspheres with smooth surfaces, and had good thermodynamic stability. The antioxidant capacity of RES was increased after microencapsulation, and the microcapsules had pH responsiveness and could slowly release RES in simulated human gastric fluid but rapidly in simulated human intestinal fluid. Conclusion: SRAS, modified shellac with ammonia water, can be used for RES microencapsulation. SRAS/RES microcapsules can facilitate the absorption and utilization of RES in the intestinal liquid and show great promise in delivery systems for functional foods and drugs.

Key words: resveratrol, shellac resin ammonium salt, microcapsules, antioxidant activity, pH response