An update review: several extraction methods for collagen isolation in vertebrate fish

Fish are vertebrate animals with a backbone that live in marine environments, presenting a potential source of collagen due to their high protein content. Collagen is a structural protein in the body's connective tissue, contributing 25 to 30% of the total body protein. Collagen sources in fish can be found in the skin, scales, and bones. The isolation of collagen from fish involves several stages, including separation and cleaning, size reduction, removal of non-collagenous components, collagen extraction, and precipitation. The extraction method utilized in collagen isolation impacts the quantity of collagen produced. The aim of this literature review is to identify extraction methods applicable for collagen isolation in vertebrate fish, serving as a reference for selecting extraction methods in future research. The updated review method involved collecting journal data from various literature sources, obtained from national and international journals discussing collagen extraction methods in vertebrate fish. Based on the update review, the isolation of collagen from vertebrate fish is carried out using several extraction methods, including acid soluble collagen extraction, pepsin soluble collagen, water soluble collagen, organic acid ultrasound-assisted, extrusion hydro extraction, deep eutectic solvent, and supercritical fluid extraction.