Ultrasound-assisted engineering of dietary fiber from cauliflower waste: a cavitation-driven process-structure-function approach.

Cauliflower (Brassica oleracea var. botrytis) processing residues are an abundant source of dietary fiber but remain underutilized because of their high insoluble fiber content and limited functionality. This study investigated ultrasound-assisted enzymatic extraction (UAEE) as a green approach to enhance dietary fiber recovery and improve its physicochemical properties for bakery applications. The effects of ultrasonication amplitude (40-80%) and treatment time (20-40 min) on extraction yield, dietary fiber composition, particle size, functional properties, and structural characteristics were evaluated. Ultrasonication significantly (p < 0.05) increased extraction yield and soluble dietary fiber content while reducing particle size and improving water holding, oil holding, and swelling capacities. Structural analyses by SEM and FTIR demonstrated pronounced surface disruption and changes in functional group accessibility following ultrasound treatment. The modified dietary fiber was incorporated into biscuits at different substitution levels, where 10% incorporation provided the best balance between nutritional enhancement, physicochemical quality, texture, and sensory acceptability. The selected formulation biscuits also maintained satisfactory microbiological and sensory quality during 90 days of ambient storage. These findings demonstrate that ultrasound-assisted enzymatic extraction is an effective strategy for valorizing cauliflower processing waste into functional dietary fiber with improved technological performance and potential application in bakery products.