Sustained release and antioxidant activity of active potato starch packaging films encapsulating thymol with MCM-41

The properties of potato starch film were improved by the addition of thymol (Thy) encapsulated in mesoporous nano-silica (MCM-41). Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) were used to evaluate the encapsulation rate of MCM-41. The effects of Thy-MCM-41 on the mechanical, physical, and antioxidant properties, and the sustained release behavior of the film were analyzed. The presence of Thy-MCM-41 contributed to the antioxidant and UV-blocking properties of the film. The properties of the film were optimized by the addition of Thy-MCM-41 (0.5 g/100 mL), resulting in an increase in the tensile strength (TS) of the film to 4.01 MPa, a decrease in the moisture absorption (MA) to 34.81%, and a decrease in the water vapor permeability (WVP) to 1.76 × 10−8 g m−1·h−1·pa−1. The films showed stronger antioxidant activity and faster thymol release rate in 50% ethanol extract. Additionally, the release rate of thymol declined with the increase of Thy-MCM-41, with obvious sustained release behavior. This study demonstrated that the active potato starch film showing sustained release had the potential for application in active packaging.