Optimization and characterization of prawn by-product protein-stabilized emulsions processed by high-intensity ultrasound

This study explores the sustainable valorization of underutilized yellow prawn by-products by developing a novel food-grade emulsifier protein. A modified alkaline extraction process, enhanced by high-intensity ultrasound (HIU), yielded a protein concentrate with a 10.08 ± 0.84% extraction efficiency and a moderate purity of 45.03 ± 0.91%, reflecting the presence of naturally occurring components such as polysaccharides and lipids. Comprehensive characterization, including zeta potential and electrophoretic analysis, revealed maximum protein solubility at alkaline pH (10-12), attributed to increased electrostatic repulsion and unfolding, as confirmed by trypsin digestion and free sulfhydryl content measurements. These findings were further supported by improvements in water and oil holding capacities at this pH range. Emulsification parameters were optimized using response surface methodology (RSM), considering YPP concentration, oil content, HIU time, and HIU power. The RSM-optimized conditions resulted in stable emulsions at a food-compatible pH (7.0-7.5), characterized by small, uniform droplets (mean diameter: 0.35 ± 0.02 μm) and a gel-like rheology (G' > G"). These emulsions exhibited high emulsifying activity and stability, further reinforced by excellent thermal stability (45% at 80°C). This sustainable, functional emulsifier derived from prawn by-products offers significant potential for diverse food applications, promoting resource efficiency and waste reduction. • Novel sustainable emulsifier from prawn by-products. • Exceptional emulsion stability; surpasses existing alternatives. • RSM-optimized process; ensures reproducibility and scalability. • Comprehensive characterization; strengthens scientific rigor. • Significant industrial potential; reduces food waste