Chitosan is a biodegradable polysaccharide composed of N-acetyl-d-glucosamine and d-glucosamine, generated by the alkaline deacetylation of Caspase-8 Inhibitor Z-IETD-FMK (Onishi & Machida, 1999). It is the second most abundant natural biopolymer and relatively inexpensive (Ma et al., 2008). In addition, it is recognized as a nontoxic, biodegradable, biocompatible and environmentally-friendly material. Many properties that are beneficial for a protective fruit coating, including film forming capability and antibacterial effects (Vásconez, Flores, Campos, Alvarado, & Gerschenson, 2009). Nevertheless, chitosan has a few drawbacks, such as pH-dependent solubility, which can be overcome by using chitosan salts (Belalia, Grelier, Benaissa, & Coma, 2008), and high viscosity, which makes the net secondary productivity (NSP) coating slow to dry and difficult to attach in some gaps on the surface of fruits (Lin et al., 2011) thus impeding its antibacterial ability. In addition, fruits produce moisture and gaseous metabolites continuously during storage due to respiration. Respiration rates depend on storage temperature, time since harvest, commodity and condition (damaged vs intact). Chitosan coatings on the surface of fruits may initially be wet and sticky, which could discourage sales of coated fruits. Furthermore, despite initial wetness, chitosan coatings become dry and develop cracks over time. Therefore, chitosan or chitosan-based coatings have only limited short-term antibacterial effect (Geisberger et al., 2013).
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