The ocean contains about 80% of the earth's biomass and has infinite potential nutritional, medical and functional raw materials. Uses of marine ingredients include products for animal and human consumption, food processing, and other uses such as beauty. Fishmeal and fish oil are generally regarded as one of the most important fish-derived products for non-food use. However, recent technological innovations and developments in non-edible fish, as well as by-products from edible fish, have given rise to many new marine products such as bioactive compounds, marine proteins and food processing aids. The marine food processing industry produces a rapidly growing number of by-products, such as fish scraps, fins, fish skeletons, fish heads, shells, skins and fish guts, which can be converted and utilized into valuable products. Utilization of by-products is critical because increased efficiency through added value reduces waste.
Freshness of raw materials: The freshness of raw materials is closely related to the protein quality of the finished product. It is very important to shorten the time interval between fresh fish harvesting and processing, and use ice water to keep fresh fish fresh to prevent spoilage. The deterioration of fresh fish produces biogenic amines, such as histamine and cadaverine, which can be used as indicators to judge the freshness of fishmeal.