Different strains of zygomycetes fungi will be employed to produce new antimicrobial bio-composite films from citrus wastes from e.g. Borås Brämhults Juice AB. Zygomycetes fungi are well known for being safe for humans and are used in fermented food such as “tempe” in Southeast Asia. Additionally, being able to grow on a variety of metabolites as well as production of a wide range of products including ethanol, lactic acid, enzymes, and products derived from biomass, e.g. chitosan, makes them an interesting choice for industrial applications. Citrus wastes are rich in pectin, glucan and hemicellulose.
In this project the glucan and hemicellulose fractions will be fermented using zygomycetes fungi to produce the fungal biomass. The cultivation condition will be optimized in order to get the highest levels of chitosan in the fungal biomass. Fungal chitosan will be extracted from the cell wall of the obtained biomass. This will be used together with the remaining pectin of citrus waste for production of the bio-composite films that can be used as edible coatings to extend the shelf life of different food products. A casting method will be developed for preparations of fungal chitosan-pectin films and preparation conditions will be optimized to meet the requirements for food packaging industry. Antimicrobial and mechanical properties as well as the resistance for the films towards transfer of water vapour, oxygen and carbon dioxide will be optimized.
The Swedish Centre for Resource Recovery at the University of Borås has many years of experience of converting the citrus to different value added products e.g. ethanol, biogas and pectin.