Progress in chitosan-based materials: Enhancing edible coatings and films through modifications and functionalization for food preservation

Chitosan has emerged as a versatile biopolymer with significant potential in food technology, particularly for developing edible coatings aimed at preserving perishable foods. This review highlights recent advancements in chitosan extraction, modification, and functionalization, emphasizing its applications in extending the shelf life of fruits, vegetables, meat, seafood, and dairy products. Chitosan-based coatings effectively reduce moisture, oxygen, and carbon dioxide permeability, thereby delaying oxidation and respiration. Their functionality can be further enhanced by incorporating nanomaterials and bioactive compounds, which improve mechanical strength, antimicrobial efficacy, and antioxidant activity while preserving the physicochemical and sensory quality of food. The development of smart chitosan coatings, responsive to changes in pH, temperature, and humidity, offers innovative possibilities for real-time food quality monitoring. Although chitosan is generally recognized as safe (GRAS), long-term toxicity studies and regulatory harmonization are necessary to ensure consumer safety. Moreover, alternative sources such as fungal-derived chitosan present sustainable, hypoallergenic options that help address the limitations of traditional crustacean-based chitosan. Overall, the use of chitosan in food preservation not only supports improved product quality and safety but also contributes to environmentally responsible and health-conscious packaging approaches, aligning with current sustainability goals in the food industry.