Optimization and characterization of microwave and ultrasound assisted alkaline extracted pea pod peel dietary fiber

Pea pod peel is by-product of pea processing, posing environmental issue. Due to high fiber content, it can be utilized as source of dietary fiber, and its valorization offers sustainable approach for by-product reduction. Soluble (SDF) and insoluble dietary fibers (IDF) were extracted using alkaline, microwave-assisted, and ultrasound-assisted alkaline extraction. Response surface methodology optimized conditions for maximum total dietary fiber (TDF) recovery. Influence of extraction technology on TDF recovery, structural modification, and functional performance were evaluated. In microwave-assisted, solid-to-solvent ratio (0.025–0.1 g/mL) and time (3–6 min) were varied at 450 W. In ultrasound-assisted, power (150–300 W), solid-to-solvent ratio (0.025–0.1 g/mL) and time (3–12 min) were optimized. Alkaline extraction altered only solid-to-solvent ratio (0.025–0.1 g/mL). Ultrasound-assisted extraction achieved the highest TDF recovery (95.69% TDF, 28.71% SDF, 66.98% IDF) at 225 W, 0.0625 g/mL and 7.5 min, followed by microwave-assisted (88.90% TDF, 26.67% SDF, 62.23% IDF) at 0.0625 g/mL and 4.5 min and alkaline extraction (84.40% TDF, 23.35% SDF, 61.07% IDF) at 0.033 g/mL. Ultrasound exhibited lowest crystallinity (22.27% IDF, 15.24% SDF), hightest thermal resistance (270 °C), improved water (4.8 ± 0.79 g/g IDF; 3.2 ± 0.57 g/g SDF), oil-holding (2.7 ± 0.51 g/g IDF and 1.5 ± 0.29 g/g SDF), swelling capacities (7.0 ± 0.82 mL/g IDF and 4.0 ± 0.54 mL/g SDF) and smallest particle sizes (SDF 136.28 ± 0.37 μm; IDF 233.18 ± 0.25 μm). FTIR confirmed O-H, C-O, and C-H groups. Structural modifications improved hydration, binding, and overall functionality, confirming the fibers as value-added ingredients, while pea pod peel remains sustainable, cost-effective source suitable for industrial utilization through green extraction. Pea pod peel utilized as dietary fiber source. Three extraction methods compared for dietary fiber recovery. Extraction methods impacted the structural and functional attributes of the fibers. Agro-industrial by-product might be sustainably valued using assisted technologies. Ultrasound-assisted alkali extraction showed the best total dietary fiber recovery.