Ultrasound-induced modifications of fish proteins: a comprehensive review of structural, physicochemical, functional...

Fish proteins are valuable biomolecules widely used in food systems due to their diverse structural, physicochemical, and functional characteristics. Improvement of these properties is important for enhancing food quality and functionality. Recently, ultrasound has emerged as a promising non-thermal technique, but optimal ultrasonic conditions for fish protein modification are context-specific to the species, target functional properties, and processing objectives. However, comprehensive literature investigating ultrasound-induced structural modifications in fish proteins and their subsequent effects on physicochemical properties, functional performance, and industrial applications remains limited. The primary purpose of this review is to examine recent advancements in ultrasound-induced modifications of fish proteins, focusing on the mechanisms involved and their impact on structural, physicochemical, and functional properties. This study systematically evaluated those modifications at the primary, secondary, tertiary, and quaternary levels of protein structures. Induced effects influence physicochemical properties, such as increased solubility, hydrophobicity, sulfhydryl reactivity, thermostability, zeta potential, and reduced particle size, which collectively enhance emulsification, foaming, gelation, and digestibility. Ultrasound-induced modifications support emerging applications across food, nutraceutical, packaging, agricultural, and pharmaceutical sectors. The key issues discussed primarily involve variability in ultrasonic parameters, protein diversity, and scalability limitations, and recommend future research focusing on parameter optimization, standardized methodologies, and industrial-scale validation. From this perspective, the study offers a reference framework to facilitate ultrasonic-assisted processing of fish proteins and enable value addition, sustainable utilization, and innovation in the blue bio-economy.