Chemical approaches to improve resistant starch type 4 content and functional properties of cassava starch

This review examines chemical modification strategies for enhancing resistant starch type 4 (RS4) content and functional properties of cassava starch (2005-2025) using the Methodi Ordinatio framework and bibliometric mapping to reveal trends and key techniques. Key modification techniques including esterification, cross-linking, acid hydrolysis, acetylation, and combined approaches were evaluated for their structural mechanisms and techno-functional effects. Findings demonstrate that optimized treatments can increase RS4 yields by 40-60 %, improve thermal stability, and enhance techno-functional characteristics such as water-binding, emulsifying capacity, and structural integrity. Eco-friendly reagents such as citric and acetic acids showed potential for sustainable, food-grade modification. Applications in bakery products, breakfast cereals, and gluten-free breads demonstrated better texture and reduced glycaemic index. Overall, the study highlights the synergy between chemical innovation and green chemistry principles and proposes future directions for scalable industrial processing, nutritional validation, and functional food development based on modified cassava starch.