Nanocellulose in food science: structure–property relationships, functional applications, safety, and future perspectives

Nanocellulose, a nanoscale material derived from renewable biomass, has attracted increasing interest in food science because of its high mechanical strength, large specific surface area, tunable surface chemistry, film-forming ability, and barrier properties. This review critically summarizes recent advances in the use of nanocellulose in food-related applications, with particular emphasis on sustainable food packaging, edible films and coatings, active and intelligent packaging systems, food freshness monitoring, and agro-industrial waste valorization. Nanocellulose can improve the mechanical, oxygen-barrier, and water-vapor barrier properties of biodegradable packaging materials, thereby contributing to extended food shelf life and reducing reliance on petroleum-based plastics. Its incorporation into edible films and coatings, together with essential oils, probiotics, vitamins, antioxidants, or other bioactive compounds, can provide additional antimicrobial, nutritional, and protective functions. In smart packaging, nanocellulose can serve as a matrix for colorimetric sensors and other indicator systems that can track changes in food freshness and spoilage in real time. Nanocellulose production from crop residues and food processing waste such as sugarcane bagasse and fruit peels also offers opportunities for resource recovery and circular bioeconomy approaches. However, production cost, energy consumption, material aggregation, moisture sensitivity, large-scale processing, safety assessment, regulatory approval, and commercialization remain challenges. Overall, nanocellulose presents significant opportunities for developing sustainable, functional, and intelligent food systems, but standardized material characterization, commercial-scale production, and comprehensive safety evaluation are still needed.