One of the most critical challenges that humanity currently faces is the production of enough food for an expected population of 9.6 billion people by 2050.

Global per capita fish consumption has more than doubled in the last fifty years, in line with increasing demand by a growing, wealthier, and more urbanised population.

Up to the 1980s, demand was mainly met by increased wild capture, but aquaculture has rapidly closed the gap, equating production and consumption with fisheries in the last years.

The production of aquaculture fish around the world achieved 80 million tons in 2016, supposing 48% of the total fish captured, transformed, and marketed.

Although in some countries fish species are conventionally marketed as whole fish, fillet presentations are growing year after year around the world.

As a result, by-products generated in the filleting process (heads, trimmings, frames, viscera, even skins) represent a new source of waste in fish farming plants.

In many cases, this residual biomass accounts for about 60% of the total fish weight and must be managed to avoid environmental health problems.

Those fish by-products are commonly used for the production of silage, fish meal, and fish oil. However, other valorisation processes, in line with circular economy principles, have been developed for the generation and extraction of valuable products such as fish protein hydrolysates, peptones, collagen, or gelatins.