Antimicrobial aerogel pads from Holo-CNF emulsions: Sustainable active packaging for enhanced strawberry preservation

This study developed a sustainable and intelligent antimicrobial aerogel for food preservation, engineered by crosslinking gelatin (GE) with dialdehyde holocellulose nanofibers (Holo-DNF) derived from agricultural waste (buckwheat husk). The resulting robust three-dimensional network, optimized at a Holo-DNF/GE volume ratio of 1:3, exhibited superior mechanical integrity, as reflected in the highest water adsorption capacity (44.31 ± 0.59 g) and the lowest shrinkage (3.49 ± 0.42 %). The material design leveraged the distinct properties of two nanocellulose derivatives: Holo-DNF, with its high aldehyde content, acted as an effective macromolecular crosslinker to build the structural scaffold, while holocellulose nanofibers (Holo-CNF) was selected for its superior emulsifying capability and larger specific surface area to stabilize citral-loaded Pickering emulsions. These emulsions were then incorporated into the aerogel to impart active antimicrobial functionality, achieving a synergy between the physical barrier and the sustained release of citral. In vitro assays confirmed significant antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Botrytis cinerea. In strawberry preservation trials, the composite aerogel (Aerogel C2, with containing 20 % Holo-CNF-stabilized emulsion) markedly outperformed control groups in day 5, including a 42.21 % reduction in weight loss, maintenance of the lowest pH and highest total soluble solids (TSS) content, and effectively restriction of total viable count (TVC) to 3.26 ± 0.03 log CFU/g, compared to 5.20 ± 0.09 log CFU/g in the control. This work presents an eco-friendly strategy for converting agricultural waste into advanced intelligent packaging, thereby offering an effective solution for extending the shelf-life of perishable fruits.