Chitosan and its derivatives: a comprehensive review on structure, properties, andemerging applications

Purpose This study aims to address the urgent need for sustainable, functional materials derived from shellfish processing waste, focusing on chitosan – a versatile biopolymer with high potential across multiple industrial domains. Design/methodology/approach A comprehensive review of the literature from the past two decades, examining chitosan’s chemical structure, modification strategies and its wide-ranging applications in areas such as food, agriculture, pharmaceuticals, medicine, cosmetics, textiles, paper, environmental chemistry and cutting-edge fields like biomedicine and nanotechnology. Findings Chitosan’s inherent antimicrobial, antioxidant and biocompatible properties make it ideal for use in nutraceuticals, cosmeceuticals, therapeutic agents, active packaging, water treatment and bio-coatings. Its versatility allows integration into advanced applications (e.g. drug delivery, bio-imaging, freshness indicators), positioning it as a valuable resource for sustainable innovation. Practical implications This review demonstrates chitosan’s capacity to transform industry by using shellfish waste to create eco-friendly, high-performance materials. It highlights the readiness of several technologies for commercialization while identifying areas – such as edible coatings and smart packaging – that require further development and industrial adoption. Originality/value By consolidating recent advances, this review spotlights chitosan and its derivatives as a sustainable frontier for material science and industrial applications, offering a valuable reference for researchers and practitioners seeking to bridge green chemistry with high-value industrial innovation.