Preparation and characterization of a thymol nanoemulsion-loaded multifunctional sustained-release corn straw cellulose nanocrystal/acetylated starch-based aerogel and its application in chilled meat preservation

Chilled meat is prone to microbial contamination during storage, resulting in a shortened shelf life. This study developed multifunctional biodegradable aerogel with water absorption, antibacterial, and sustained release properties as a preservation pad for meat, using corn straw cellulose nanocrystals (CSCNCs) and acetylated starch (AS) as the structural skeleton and thymol (TMO) nanoemulsions as antimicrobials. The effects of different mass ratios of CSCNCs/AS on the morphology, structure, physical properties, and release behavior of aerogels were systematically analyzed. Additionally, their antibacterial properties, biocompatibility, and biodegradability were investigated. The results showed that the aerogels with CSCNC/AS mass ratio of 1:5 had a tailored structure for loading TMO nanoemulsions, as well as excellent water absorption, mechanical properties, and thermal stability. Due to strong hydrogen bonding and a porous structure, the TMO in the aerogels was continuously and uniformly released into high-water-activity and fatty food simulants, mainly controlled by Fickian diffusion. Furthermore, it exhibited superior antibacterial properties and biocompatibility. The application of aerogels for chilled beef preservation extended the shelf life from 8 days to approximately 12 days, which was superior to commercially available preservation pads. Notably, the aerogels exhibited superior biodegradability in soil. Therefore, the prepared aerogel preservation pads showed great potential in preserving chilled meat.