ABSTRACT
2Biodegradable packaging materials are gaining increased popularity over the years as synthetic plastic materials cause serious environmental concerns due to their non-biodegradation and depletion of natural resources. Biodegradable materials offer a possible alternative as they are abundant, renewable, inexpensive, and environment friendly. Biopolymers are produced from various natural resources through direct extraction, chemical synthesis, or fermentation by microorganisms, such as starch, cellulose, proteins, polylactide (PLA) and polyhydroxyalkanoates (PHAs), and these are considered as attractive alternatives for non-biodegradable petroleum-based plastics. Bio-based polymers applied as dispersion coatings on paper and paperboard could be used to provide sufficient barrier properties with respect to fats, but these provide moderate water vapor barrier properties. Other drawbacks of the bio-based packaging could be inferior mechanical properties, insufficient heat tolerance, and high moisture sensitivity as compared to petroleum- derived plastics. These problems could be overcome by physical, chemical or enzymatic treatments, and by blending with hydrophobic additives or making multilayer films with varied properties. In addition, fiber-based packaging has the advantage of lower weight, which is favorable for transportation, and the final products can generally be recycled. The bio-based packaging materials and edible coatings are also being applied to fruits and vegetables for maintaining their quality and extending shelf-life. Being biobased in nature, most of these materials are also edible in nature and can be consumed along with the commodity.
