Currently, the exploitation of natural resources and the increase in environmental pollution have created the need to utilise co-products and low value-added fish species to develop high value-added products. Many studies are using underutilised species to obtain myofibrillar proteins, protein isolates and hydrolysates, which can be considered high added value products. Fish protein isolates have shown good functional properties for application in different food formulas and also in the preparation of hydrolysates, as they reduce the content of pro-oxidising compounds that can affect their stability. These processes can result in protein hydrolysates with good bioactive properties, such as antimicrobial, antioxidant and anticancer properties, among others. Proteins have biologically active peptides, which are inactive within the protein sequence but can be released during processes such as enzymatic hydrolysis.