A comparative review of chitin occurrence and quantification methodologies with applications to insect sourced materials

Chitin is an abundant aminopolysaccharide that serves as the basic structural molecule in certain animal lineages and fungi. Chitin is a diverse polymer with research and industrial applications across several disciplines. The primary source of chitin is the exoskeleton of arthropods, which include insects and crustaceans. However, chitin does not occur as a pure polymer, but rather as a complex matrix that integrates proteins, pigments, and minerals. Methods for analyzing chitin thereby must deal with the chemical complexity of these biological matrices. Accordingly, several analytical methods have been developed for chitin detection and quantification. Here we provide a detailed summary of methods for the quantification of chitin, with a focus on insect-based materials. These methods fall into several broad categories: proximate analysis, spectroscopic, electrophoretic and chromatographic separation paired with detection, chemical, and immunochemical. Also included is a discussion on methods for chitin purification, hydrolysis, and deacetylation. The aim of this review is to consolidate chitin quantification methodologies across diverse scientific disciplines, providing researchers with a comparative framework for selecting appropriate techniques based on their sample types, research objectives, and analytical constraints. By highlighting the strengths and limitations of each method, this review also seeks to guide future method development.