Deacetylated konjac glucomannan films functionalised with carboxylated cellulose nanofiber and anti-browning components for fresh-cut apple preservation

Preservation of fresh-cut fruits is crucial due to their susceptibility to oxidative browning, and environmentally friendly food packaging has emerged as a promising solution. In the present study, deacetylated konjac glucomannan/carboxylated cellulose nanofibers (DKGM/CCNF) composite films were prepared through a stepwise reinforcement strategy. L-Cysteine and glutathione, screened as the two best anti-browning substances, were respectively loaded into the DKGM/CCNF composite films. The anti-browning effect and mechanism of the DKGM/CCNF functional films were explored on fresh-cut apples. The results demonstrated that deacetylation improved the mechanical properties, surface hydrophobicity, and thermal stability of the films. The incorporation of CCNF further improved the mechanical properties, surface hydrophobicity, and water vapor barrier properties of the films. The fresh-cut apples packaged in the DKGM/CCNF functional films exhibited satisfactory appearance during the 9 d storage. The browning of fresh-cut apples was inhibited by enhancing the activity of related antioxidant enzymes, maintaining higher total phenolic content, and reducing hydrogen peroxide levels. Overall, the DKGM/CCNF functional films prepared in the present study have the potential application prospects of extending the shelf life of fresh-cut fruits.