A Review of Polysaccharide-Zinc Oxide Nanocomposites as Safe Coating for Fruits Preservation

Abstract

Safe coating formulated from biopolymer can be an alternative for better packaging for fruits. Among biopolymers used for safe coating, polysaccharides attracted more attention due to its biocompatibility and edibility. However, polysaccharide-based materials have weaknesses such as low water barrier and mechanical properties which result in lower capability on preserving the coated fruits. Hence, the incorporation of nanoparticles (NPs) such as zinc oxide (ZnO) is expected to increase the ability of polysaccharide-based coating for the enhancement of fruit shelf life. In this review paper, the basic information and the latest updates on the incorporation of ZnO NPs into the polysaccharide-based safe coating for fruit are presented. Various research has investigated polysaccharide-ZnO nanocomposite safe coating to prolong the shelf life of fruits. The polysaccharides used include chitosan, alginate, carrageenan, cellulose, and pectin. Overall, polysaccharide-ZnO nanocomposites can improve the shelf life of fruits by reducing weight loss, maintaining firmness, reducing the ripening process, reducing respiration, reducing the oxidation process, and inhibiting microbial growth. Finally, the challenges and potential of ZnO NPs as an active agent in the safe coating application are also discussed.

Biodegradable Alginate Films with ZnO Nanoparticles and Citronella Essential Oil—A Novel Antimicrobial Structure

“…Alginate is water-soluble, can be easily handled and functionalized [ 10 ], and is a natural choice for active packaging due to its lack of toxicity [ 11 , 12 ], US-FDA considering it as GRAS (Generally Recognized As Safe) [ 13 ]. Plasticizers are usually added to improve some of the mechanical properties of alginate films, glycerol being most often used due to its good compatibility [ 14 ]. Mechanical properties can be enhanced furthermore by reinforcing the biopolymer with nanoparticles (NPs), their inclusion improving also the barrier properties.…”

“…The introduction of ZnO nanoparticles into the food packaging will enhance the antibacterial activity [ 14 ] and will improve the UV-barrier of the polymeric film. Both qualities will extend the shelf life of the packed food [ 47 ], but there is an associated concern about the risks posed by the potential migration of NPs into the food, and further into the human body.…”

“…While there are reports for chitosan or cellulosic edible films with ZnO nanoparticles for cheese packaging [ 70 , 71 ], in the alginate case none of them contain ZnO. There are few reports of alginate–ZnO packaging films for fruits [ 14 , 72 ]. Therefore, alginate was chosen as the film forming biopolymer, in which ZnO nanoparticles were added as filler and antibacterial agent.…”

Polysaccharide-Based Packaging Functionalized with Inorganic Nanoparticles for Food Preservation

“…ZnO is an available an low-cost material with excellent compatibility and easy incorporation into polysaccha ride-based matrix [42]. Furthermore, ZnO nanoparticles have improved the physicochem ical, mechanical, antimicrobial, and water-related properties of some polysaccharide based materials with potential for food packaging development due to its ability to inter act with the hydroxyl (-OH) groups in the polysaccharide chains [39]. Table 2 summarize the application of polysaccharide-ZnO packaging and their effects on quality parameter of various food products.…”

“…Figure 3. Application of organic-inorganic hybrid film for food preservation by dipping (a) and coating (b) methods (adapted from Tunma[37] and Anugrah et al[39]). …”