A bioactive chitosan-based packaging for food preservation

This work focuses on the production of a bioactive film designed for food wrapping applications by using chitosan synthesized from fish waste (crustaceans), and plant extracts. The synthesis of chitosan involved two distinct approaches aiming at converting chitin into chitosan: i) chemical - deproteinization and deacetylation of the discarded material; ii) fermentative - microbial fermentation by using Bacillus subtilis and Serratia marcescens strains. The film has been obtained by stratification of a thin layer (range of thickness, 150-300 μm) that can effectively wrap food products. Successively, the biofilm has been subjected to mechanical testing: break stress, elongation at break, hardness, and glass transition temperature. Microbiological tests have been performed on semi-hard cheese samples wrapped with the chitosan-based biofilm (treated group, T) and with conventional PVC film (control group, C) by analyzing the microbial load, such as mesophilic and acidophilus microbia, to determine the biofilm's effectiveness in inhibiting spoilage. In parallel with the microbiological testing the aromatic fraction of the wrapped cheese samples (both C and T groups) has been monitored by means of SPME-GC-MS technique, in order to evaluate any potential changes in the flavor profile. This analysis provided valuable information regarding the impact of the chitosan-based biofilm on the sensory quality and aroma stability of the wrapped food products. The study contributes to the advancement of sustainable and functional food packaging materials with potential applications in the food industry.