Development of Chitosan-Based Biopolymer Films Incorporating Essential Oils for Food Packaging Applications in Nigeria

Petroleum-based plastic packaging poses significant environmental challenges in Nigeria, where waste management infrastructure is inadequate and plastic litter is pervasive. Chitosan, derivable from crustacean shell waste abundantly available from coastal communities in South South Nigeria, offers a biodegradable alternative for food packaging applications. This study developed and characterised chitosan biopolymer films incorporating essential oils as active food packaging materials. Chitosan was extracted from shrimp shell waste from fishing communities in Akwa Ibom State and characterised for degree of deacetylation, viscosity, and molecular weight. Films were prepared by solution casting with incorporation of clove, oregano, and lemongrass essential oils at concentrations of 0.5, 1.0, and 2.0 percent. Films were characterised for tensile strength, elongation at break, water vapour permeability, oxygen permeability, light transparency, colour, moisture content, swelling index, and antimicrobial activity. All essential oil-incorporated films showed significantly reduced water vapour permeability compared to neat chitosan film, with clove oil-containing films achieving a 42 percent reduction at 2 percent concentration. Tensile strength was maintained above food packaging minimum requirements in films containing up to 1 percent essential oil. Antimicrobial activity against Salmonella enterica and Aspergillus niger was demonstrated, with inhibition zones proportional to essential oil concentration. The 1 percent lemongrass oil film showed the best balance of mechanical properties, barrier performance, and antimicrobial activity. Application of this film to fresh tomato storage extended shelf life by 4 days compared to unpackaged controls at ambient temperature. This research demonstrates a locally resourced, biodegradable, and functional food packaging material for the Nigerian market.

Keywords: chitosan film, essential oils, active food packaging, antimicrobial, biopolymer