Anti-Oxidative and Antibacterial Self-Healing Edible Polyelectrolyte Multilayer Film in Fresh-Cut Fruits

Abstract

The consumption of fresh-cut fruits is limited because of the oxidation browning and pathogenic bacteria's growth on the fruit surface. Besides, crack of the fresh-keeping film may shorten the preservation time of fruit. In this work, polyelectrolyte multilayer (PEM) film was fabricated by layer-by-layer (LBL) electrostatic deposition method. The film was made by carboxy methylcellulose sodium (CMC) and chitosan (CS). The as-prepared PEM film had good anti-oxidative and antibacterial capability. It inhibited the growth of Gram-negative bacteria and the antibacterial rate was more than 95%. The stratified structure and linear increase of the absorbance in the film verified a linear increase of film thickness. The slight scratched film could self-heal rapidly after the stimulation of water whatever the layer number was. Moreover, the film could heal cracks whose width was far bigger than the thickness. The application of PEM film on fresh-cut apples showed that PEM film had good browning, weight loss and metabolic activity inhibition ability. These results showed that the PEM film is a good candidate as edible film in fresh-cut fruits applications.

Chitosan-Based Layer-by-Layer Assembly: Towards Application on Quality Maintenance of Lemon Fruits

“…e phenomenon was presumably related to the swelling behavior of the chitosan coating in the humid atmosphere, or related to the crosslinking between CMC and chitosan which results in a formation of a more loosely packed poriferous matrix rather than of a denser one and enlarges the intermolecular space and promotes the transport of water molecules in the assembly structure. It was consistently reported that the stratified structure and linear increase in the absorbance verified a linear increase in coating thickness [28]. In addition, the mechanical properties of the LBL assembly were significantly improved, in terms of both strength and elasticity (p < 0.05, Table 1).…”

Recent advances in self‐healing materials for food packaging

“…Moreover, the addition of chitosan endowed the fabricated PEM coating with the free radical scavenging activity of 78.62%, and the antibacterial capacity of 100% and 95.48% against Salmonella and E. coli, respectively. 31 A similar PEM coating was manufactured from CMC, chitosan, and CaCl 2 for the storage of lemons under refrigerated conditions for up to 60 days. 115 It was revealed that the increased thickness of coating contributed to the higher cross-linking degree and led to the enhanced gas barrier, mechanical, and self-healing properties.…”

“…Reversible electrostatic interactions can be initiated between the charged polymers and ions, 52 polyelectrolytes, 64 polyampholytes, 65 and zwitterionic fusions, 66 resulting in the formation of self‐healing films, 31 hydrogels, 12 and aerogels 67 . For instance, a polyelectrolyte multilayer (PEM) film with self‐healing ability was constructed from polydopamine and SA by layer‐by‐layer (LBL) assembly 68 .…”

“…Overall, self-healing materials for food packaging applications are a relatively new topic but have great potential. Hitherto, different forms of selfhealing materials have been reported, such as fibres, 24,25 hydrogels, [26][27][28] microcapsules, 22 films, [29][30][31] and coatings. 14,32 Among them, self-healable fibres with high aspect ratios are commonly applied for producing batteries.…”

Approach of Electrostatic Interaction Based Layer-by-Layer Assembly of Cationic Guar Gum and Poly (Carboxylic acid)

“…In the early 1990's, Decher et al developed a simple but effective way to prepare ultrathin polyelectrolyte multilayer film via layer-bylayer (LbL) assembly [16,17]. Polyelectrolyte multilayers (PEMs) have received extensive attention in the past decade due to their promising applications in very diverse fields [18] such as chemical sensors [19] optical devices [20], biosensors [21] light-emitting diodes [21], biomedical coatings [22][23][24], Antioxidative and Antibacterial Self-Healing [25]. The driving force for the LbL assembly of oppositely charged polyelectrolyte chains is mainly attributed to the electrostatic interactions [17].…”