Preparation techniques, functional properties, and applications of nanochitin in food and agriculture: A review

Nanochitin is nanoscale chitin in the form of nanocrystals and nanofibers. Its preparation and modification pose certain challenges. The eco-friendly and sustainable preparation technique has gained significant interest. Ongoing innovations in preparation and precise control of its structure and physiochemical properties drive diverse applications in food and sustainable agriculture practices. This review critically examines the methodological differences in the preparation of chitin nanocrystals and nanofibers, emphasizing the resulting structural properties and their implications for functional performance. It delves into the nuances of methodological variations and their impacts on the physicochemical characteristics of nanochitin, exploring how these attributes facilitate specific applications in food and agriculture, including food packaging, emulsion systems,nutritional enhancements, and improvements in agricultural productivity. Chemical, physical, and combined extraction methods can yield chitin nanocrystals and nanofibers of different lengths and shapes. These methods profoundly influence the physicochemical properties of the resultant nanochitin, which, in turn, determines its functionality and scope of application in food and agriculture sectors. This review has also spotlighted the current challenges inherent in these extraction processes, such as scalability, environmental impact, and cost-effectiveness. Looking forward, the potential of nanochitin to revolutionize food and agricultural systems is profound. Innovations may include the development of nanochitin-based vertical farms, its application as a fat substitute, and its utility as biodegradable 3D printing ink for food packaging. These applications harness the unique properties of nanochitin, pushing the frontier of its utility in sustainable practices.