Functionally active proteins from seafood side streams and their applications

Abstract: Availability of nutritive proteins is facing problems all over the world. The situation demands exploration of novel sources of proteins to address the rising demand. Seafood side streams can be a feedstock of acceptable nutritionally valuable proteins. These sources include bycatch fish landed during commercial fishing that have poor food value, process discards and effluents generated during processing of commercial fish and shellfish. As high as 50 t0 60% of the fish and shellfish is discarded, which consist of shell, head, fileting frames, bones, viscera, fin, skin, roe, and others. The seafood industry including aquaculture also releases voluminous amounts of protein-rich effluents. While the bycatch can serve as raw material for protein-rich edible products, the process discards and effluents can provide nutritive proteins. These proteins can be recovered through biorefining employing upcoming, environmental-friendly, low-cost green processes, which include uses of enzymes, microorganisms and non-thermal processes. Cultivation of photosynthetic microalgae in nutrient media consisting of the side streams generates algal cell mass, from which nutritionally important proteins and also other nutrients can be recovered by novel processes. A zero-waste marine bio-refinery approach can help almost total recovery of the proteins and other ingredients from the seafood side streams. The recovered proteins can have interesting applications as nutraceuticals and food additives and can address protein scarcity.