Non-thermal processing of fish: Evolution of flavor, physico-chemical properties, and bioactivities

Fish serve as a vital source of protein and lipid for human nutrition, with value-added products exhibiting bioactivities beneficial to human health. After harvesting, fish are predominantly consumed fresh, while the remainder undergo further processing, including freezing, curing, surimi production, etc. Compared to conventional methods, non-thermal processing technologies (NTPs), such as ultrasound and ultra-high pressure (UHP), offer distinct advantages in improved efficiency and reduced quality loss. Characterized by relatively low operating temperatures, NTPs are suitable for workflows requiring less energy input. However, excessive processing may also lead to a deterioration in product quality. Consequently, reconciling process intensification with quality preservation (flavor, texture, color, etc.) represents an urgent challenge. Furthermore, expanding NTP application scenarios (such as regulation of flavor substance generation, controllable oxidative modification of proteins, and improved bioactivities of by-products (protein peptide powder and fish oil)) remains a critical research priority. This chapter comprehensively reviews the scope and efficacy of key NTPs-focusing on ultrasound, UHP, electromagnetic fields (EF), and cold plasma-in fish muscle and by-product processing while elucidating their underlying mechanisms.