Physicochemical, antibacterial, and biodegradability properties of green Sichuan pepper (Zanthoxylum armatum DC.) essential oil incorporated starch films

This study aimed to develop a degradable packaging film based on a starch/chitosan mixed base incorporating different amounts (0–2.5%, v/v) of Zanthoxylum armatum DC. essential oil (ZEO). Gas Chromatography-Mass Spectrometry (GC-MS) analysis showed that the main constituents of ZEO are linalool and d-limonene. The physicochemical properties and microstructure of the films were analyzed. ZEO incorporation improved the mechanical properties of the films, the water vapor permeability (WVP) first decreased and then increased with a minimum value of 5.16 × 10−11 (g·Pa−1 s−1 m−2). With 2.5% ZEO, the film showed the lowest water solubility (WS) (17.01%) and the best antibacterial activity with inhibition zones of up to 21.72 ± 1.25 and 18.73 ± 0.74 (cm) against S. aureus and E. coli, respectively. The microstructure analysis showed that ZEO addition improved interaction between the film components. Furthermore, it significantly influenced the surface roughness of the composite film. Based on soil burial tests, SCKZ films showed good biodegradability in the natural soil environment. In conclusion, SCKZ films can be good food packaging material, especially for high-fat or fried foods that are susceptible to microbial contamination.