One of the major objectives of food industry is to develop low-cost biodegradable food packaging films with optimal physicochemical properties, allowing for their large-scale production and providing a variety of applications. To meet the expectations of food industry, we have fabricated a series of solution-cast films based on common biodegradable polysaccharides (starch, chitosan and alginate) to be used in food packaging applications. Selected biopolymers were modified by the addition of glycerol and oxidized sucrose (starch), glycerol (chitosan), and glycerol and calcium chloride (alginate), as well as being used to form blends (starch/chitosan and starch/alginate, respectively). A chestnut extract was used to provide antibacterial properties to the preformed materials. The results of our studies showed that each modification reduced the hydrophilic nature of the polymers, making them more suitable for food packaging applications. In addition, all films exhibited much higher barrier properties to oxygen and carbon dioxide than commercially available films, such as polylactic acid, as well as exhibiting antimicrobial properties against model Gram-negative and Gram-positive bacteria (Escherichia coli and Staphylococcus epidermidis, respectively), as well as yeast (Candida albicans).
Keywords: alginate; barrier properties; biopolymers; chitosan; modification; polysaccharide; starch.