Development and characterization of an edible chitosan–whey protein nano composite film for chestnut (Castanea mollissima Bl.) preservation

Abstract

Chitosan (CHI) and whey protein are usually used to prepare edible films for food preservation. However, the composite film composed of the two components does not yield satisfactory properties for chestnut preservation. In this study, nano‐cellulose and cinnamaldehyde (CMA) were added to CHI and whey protein, creating a new composite film with strong water retention, bacteriostatic, and mechanical properties. The water vapor permeability (WVP) of the film decreased by 21.61% with the addition of 0.5% (w/v) nano‐cellulose, and 23.02% with the addition of 0.3% (w/v) CMA. Furthermore, water solubility (WS) decreased 22.05%, and the density of the film was significantly improved with the addition of 0.3% (w/v) CMA. The optimized formula of the film was CHI 2.5% (w/v), whey protein 3.0% (w/v), nano‐cellulose 0.5% (w/v), CMA 0.3% (w/v), and pH 3.8, as determined by orthogonal testing L9(34), with fuzzy comprehensive assessment, of WVP, WS, tensile strength, and elongation at break. The film clearly inhibited the growth of E. coli, S. aureus, and Chinese chestnut fungus, destroying the mycelial structure of the fungus. In addition, coating effectively reduced the weight loss, mildew rate, and calcification index during 16 days of storage of chestnuts at 25 °C.

Physiological response of chestnuts (Castanea mollissima Blume) infected by pathogenic fungi and their correlation with fruit decay

“…Therefore, the mechanical damage in picking and post-harvest circulation should first be reduced to decrease the chance of pathogen infection. Furthermore, the physical methods such as low temperature, modified atmosphere, and edible film ( Fernandes, Pereira, Fidalgo, Gomes, & Ramalhosa, 2020 ; Huang et al, 2020 ), or the chemical methods such as ClO2 and O3 ( Vettraino et al, 2019 ), or the biological methods such as natural extracts, antifungal bacteria, and microbial metabolites ( Silva-Campos, Callahan, & Cahill, 2022 ) should be properly used during storage and transportation. These techniques mainly played a role in the following two aspects: on the one hand, the use of substances with antifungal effect or the creation of an environment unfavourable to the growth of pathogenic fungi to reduce the infection; on the other hand, the increase of resistance of chestnut fruits to resist the infection of pathogenic fungi.…”

Development and Characterization of an Edible Zein/Shellac Composite Film Loaded with Curcumin

“…Escherichia coli ( E. coli ), a common Gram-negative bacterium, was selected as the test bacterium, and the antibacterial activities of the ZS–Cur films were measured by the bacteriostatic circle method. For the antimicrobial test method, readers are referred to Huang et al [ 41 ]. The prepared plate count agar (PCA) solution (25 mL) was poured into a sterile medium, solidified after being sterilized and cooled, inoculated with 0.5 mL of the strain suspension (1 × 10 7 CFU/mL), and evenly coated.…”

Valorization of cheese whey: closing the loop from protein extraction to whey protein film composting

“…For the preservation of chestnuts, the development of chitosan/whey protein composite films was carried out. 13 Nevertheless, these studies are just focused on one part of the whole process, with no further examination of the method employed for the extraction of the protein or the impact that these new procedures could have on the environment. These aspects are essential to prove the sustainability of the new material.…”