Tough, antibacterial, antioxidant, antifogging and washable chitosan/nanocellulose-based edible coatings for grape preservation

This study focused on extracting nanocellulose from food processing waste to create a multi-functional edible coating for preserving grapes. Nanocellulose, in the form of short rods with diameters ranging from 30 to 130 nm, was extracted from soy hulls. Edible coatings were then prepared through an ion cross-linking method. Results revealed that the film surfaces and cross-sections were smooth, flat and pore-free, with monomers cross-linked through hydrogen bonding, ester bonds and electrostatic interactions. Further, the incorporation of soy-hull nanocellulose (2 g) effectively improved the mechanical strength (elongation = 281.03 % and tensile strength = 114.88 MPa), barrier properties and antifogging and antibacterial properties (95.55 %) of SCT composite films. Moreover, compared with the control, the SCT-3 coating can extend the shelf life of grapes to 10 d at 25 °C. This study offers a new perspective on the high-value use of agricultural by-products and development of edible films.