In the last decades the exponential growth of the world’s population and the consequent rapid increase in urbanisation and industrialisation have led to a massive increase in fish production, both from capture fisheries and aquaculture. In the last few years, the consumption of seafood has seen a huge increase since it has been recognised as a key component of a balanced diet and healthy lifestyle. In fact, it’s not only a source of healthy proteins and lipids, but it is also has many essential nutrients such as fatty acids, optimal for the brain development, and iodin which allows the thyroid to properly function. Furthermore, it contains vitamins and minerals, such as iron and calcium, necessary for a proper bone development.
Increase in fishery side-streams
The recent increase in fish production has led to a significant increase in fishery side streams around the world, creating huge environmental and economic concerns. The FAO has estimated that annually up to the 35% of the fisheries and aquaculture products is either lost or wasted. The fish supply chain produces an increasing amount of side streams which are represented by byproducts and coproducts of industrial processes that are still little or not exploited at all. Moreover, the 70% of the fish undergoes further processing resulting in the production of large quantities of waste depending on the processing level.
“Unwanted catches”
Considering the increase in the fishery side streams, the so call “unwanted catches” or “by-catches” create a huge environmental and economic concerns. The exclusion of these species occurs for many different reasons, such as undersized or surplus fish that fisheries do not have a quota for, as well as endangered, threatened and protected species, and other unwanted marine species.
“Collagen and gelatine”
Bioactive compounds extractable from fishery side-streams are a good source of collagen and gelatine, that are currently used for many different purposes, especially in the cosmetical and pharmaceutical fields. Collagen and gelatine are two different forms of the same macromolecule. However, gelatine can be defined as partially hydrolysed form of collagen.
“Marine vs bovine gelatine”
Nowadays the demand for fish-derived gelatine is increasing. In fact, unlike bovine gelatine, fish gelatine is not associated with health risks such as bovine spongiform encephalopathy, nor does it raise religious or cultural concerns. Moreover, compared to the red meat proteins, fish proteins present a high nutritive value and have unique functional properties such as water binding capacity, emulsifying capacity, film capacity and forming capacity.
“Fatty acid and oxidation”
Fisheries contain between 2% and 30% of fat in the muscle’s tissues, skin, head, bones and in the bowels. The positive effects of semi essential fatty acids of the omega three series are widely use in the food and cosmetic industries. It is important to remember that these compounds being highly unsaturated are extremely delicate as they’re easily oxidised. It will therefore be necessary to use destruction and formulation techniques that respect these characteristics to maintain a high quality of the finished product.
Chitin and chitosan
Seafood byproducts, particularly crustation, including shrimp, crab, lobster and grill, are the primary sources of chitin and chitosan for commercial uses. Chitin is a natural polymer that can be easily found in nature, since it’s only second to cellulose. On the other hand, chitosan derives from chitin that went through a process of partial deacetylation using chemical or biological techniques. Both chitin and its derivatives exhibit excellent biodegradability and biocompatibility within the human body and present a wide range of biological and techno functional properties. For this reason, they are widely used in many fields such as biomaterials, packaging, excipients and dietary ingredients.
Carotenoids
Carotenoids are the main fat-soluble pigments present in seafood. Astaxanthin is known to be the main carotenoid extracted from oily fish and crustaceans. It is widely used in food and medical industries as a colorant, as an antioxidant and as a vitamin A precursor. Fish bones contain about the 67% of minerals including calcium, phosphorus, iron and zinc, which can be used for the formulation of dietary food supplements. The fish bones derived from processed fish waste are rich in calcium and serve as an excellent source of hydroxyapatite, a material commonly used in bone grafts for both medical and dental applications.
