Production, functionality, bioactivity, and application of fish protein hydrolysates and peptides

Fish is a nutritious food commodity and an important component of the human diet. Both the edible portions (fillets) and byproducts (e.g., skin, bones, scales, and viscera) contain approximately 20 % protein. Peptides, which are short chains of amino acids, and protein hydrolysates, which are mixtures of these peptides, are derived from fish proteins. Fish protein hydrolysates (FPHs) are produced through enzymatic hydrolysis, microbial fermentation, physical or chemical treatments, and emerging technologies such as subcritical water hydrolysis. These processes are often followed by separation and fractionation techniques to isolate purified peptides. FPHs and their constituent peptides exhibit excellent techno-functional properties, including high solubility, emulsification, and stability, along with a range of health benefits such as antioxidant, antihypertensive, and anti-inflammatory effects. These dual functionalities make FPHs valuable for applications in the food, pharmaceutical, and cosmetic industries. This chapter highlights recent advances and challenges in the sustainable production and application of FPHs and their constituent peptides.