Effect of the high barrier and hydrophobic hemicellulose/montmorillonite film on postharvest quality of fresh green asparagus

The hemicellulose materials' gas barrier and mechanical property could sharply decline in high humidity. To address this drawback and extend the applications of hemicellulose in a high humidity environment, montmorillonite (MMT) and alkyl ketene dimer (AKD) were employed as functional agents to lower the gas permeability and improve the hydrophobicity of the hemicellulose-based film. The result showed that the water vapor permeability of the hemicellulose-based film decreased by 81.7% with the addition of MMT and the contact angle of the hemicellulose-based film increased by 131.9% after AKD modification. Meanwhile, the synergistic effect of cellulose nanofibers (CNF) and MMT can significantly improve the mechanical strength and water vapor barrier performance of the hemicellulose-based films. Moreover, the complex film exhibited a better preservation effect on the fresh green asparagus in a high humidity environment (86% RH) at room temperature, significantly reducing the weight loss of green asparagus and delaying the loss of nutrients such as Vitamin C (VC), soluble protein, and other nutrients. These green hemicellulose-based films have great food preservation potential under high humidity.