Fragile fruits, which are prone to mechanical damage and microbial infection, necessitate protective materials that possess both cushioning and antimicrobial properties. In this study, we present a novel genipin-crosslinked chitosan/gelatin aerogel (CS/GEL/GNP) synthesized through direct mixing and free-drying techniques. The mechanical properties and cushioning capacities of the CS/GEL/GNP aerogel were thoroughly characterized, alongside an evaluation of its antimicrobial efficacy. The composite aerogel demonstrated remarkable compressibility and shape recovery characteristics. In a transportation simulation test, the aerogel effectively protected strawberries from mechanical damage. Furthermore, the composite aerogel exhibited enhanced antimicrobial activities against Escherichia coli, Staphylococcus aureus and Botrytis cinerea in vitro. The quality of strawberries was successfully maintained at ambient temperature when packaged with the CS/GEL/GNP. Notably, the aerogel could be completely degraded in the soil within 21 days and is nontoxic to cells. Consequently, the dual-functional CS/GEL/GNP aerogel presents a promising option for packaging materials aimed at protecting delicate fruits.

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.

Air pollution is a major environmental and public health issue. Each year, large amounts of particulate matter (PM) and other harmful pollutants are released into the atmosphere. Conventional polymer nanofiber filters lack the functionality to capture ultrafine PM. As a sustainable alternative, this work developed titanium dioxide (TiO2) nanoparticle surface-modified cellulose nanofiber (CNF) aerogels for PM2.5 filtration. CNFs were extracted via mechanical disintegration to diameters below 100 nm. The nanofibers were functionalized with 1.0-2.5 wt% TiO2 nanoparticles using citric acid cross-linking. Cylindrical aerogels were fabricated by freezing and lyophilizing aqueous suspensions. Structural, morphological, thermal, and mechanical properties were characterized. TiO2 modification increased density (11.8-19.7 mg/cm3), specific surface area (287-370 m2/g), and Young's modulus (33.5-125.5 kPa) but decreased porosity (99.6 %-97.7 %), pore size (20.2-15.6 nm) and thermal stability compared to unmodified cellulose aerogels. At 2.5 wt% loading, the optimized aerogels achieved 100 % absorption of 0.1-5 mu m particulates owing to reduced pore size. Despite enhanced filtration capabilities, the modified CNF aerogels retained inherent biodegradability, degrading over 70 % within one month of soil burial. This pioneering research establishes TiO2 functionalized CNF aerogels as promising sustainable alternatives to traditional petroleum-based air filters, representing an innovative approach to creating next-generation nanofiltration materials capable of effectively capturing fine and ultrafine particulate matter pollutants.