Effects of hydrophilic plasticizers added to chitosan coating for extending the storage life of Citrus sinensis

Abstract

The use of conventional food packaging materials is usually effective in terms of barrier. On the other hand, their nonâ€biodegradability creates serious environmental problems, motivating researches on edible biopolymer films and coatings to at least partially replace synthetic polymers as food packaging materials. Chitosan is a biopolymer obtained by Nâ€deacetylation of chitin, which is the second most abundant polysaccharide on nature after cellulose. Chitosan forms clean, tough and flexible films with good oxygen barrier, which may be employed as packaging, particularly as edible films or coatings, enhancing shelf life of a diversity of food products. Chitosan films (CH) were plasticized with two hydrophilic compounds, namely, olive oil (CHOO) and vegetable oil (CHVO). Our objective was to investigate the effect of plasticizers on the quality and storability of oranges with chitosan films. The following parameters were measured: weight loss, ascorbic acid content, pH, and firmness. The stability of the plasticized films was observed by storage for 7weeks at ambient temperature of 25±2oC and relative humidity of 55â€67%. Prior to storage, the orange samples were surface sterilized using 100mg/L sodium hypochlorite. Results showed that chitosan films plasticized with two hydrophilic compounds was effective in extending the shelflife of orange when compared to untreated control in the following order: CHOO>CHVO>CH>Control.