Quantitative study on release kinetics of thymol in food packaging films

A potato starch slow-release antibacterial film was prepared with mesoporous nano-silica (MCM-41) as a carrier to load thymol (Thy) by ultrasonic method. In order to evaluate the effect of temperature on the quantitative release of thymol from the film, release kinetics of thymol under different temperatures (5 °C, 10 °C, 20 °C, and 40 °C) were analyzed based on high-performance liquid chromatography (HPLC). Thy-MCM-41/potato starch film has good mechanical properties. Its tensile strength (TS), elastic modulus (EM) and elongation at break (EB) were 6.74 MPa, 34.94 MPa and 78.21%, respectively. Additionally, this film had a small WVP value (5.32 g m−1·h−1·Pa−1), indicating that the film had a good water barrier performance. For short-term diffusion, the estimated n-values were between 0.3978 and 0.4064, following Fick's diffusion law. The diffusion coefficient (DP) was increased with increasing temperature. For long-term diffusion, the DP values were decreased by 102 times compared with short-term diffusion, and the partition coefficient (KP, F) decreased as the temperature increased. The values of DP and KP, F reached 42.584 × 10−12 cm2 s−1, 0.893, respectively, when the temperature was 40 °C. This work offers a new method for the preparation of potato starch sustained-release antibacterial film, and provides a theoretical basis and technical support for the development of active packaging.