Seafood processing waste as a source of functional components: Extraction and applications for various food and non-food systems

Seafood processing significantly influences economic ventures worldwide and is an essential part of the food chain system. On the other hand, the fish processing units discard the processed by-products such as heads, viscera, bones and shells, even though they are nutritionally rich. Despite being rich in nutrients, processing, management and disposal of seafood waste is a serious concern. This will cause severe environmental pollution, which can be addressed by the recovery and utilization of these nutrients for human healthcare. The effluents let out by the fishery sector contain organic matter, high amounts of phosphorus, nitrogen, and antibiotics. Lipids with high amounts of polyunsaturated fatty acids (PUFA), proteins, minerals, carotenoids, and amino acids are in abundant quantities in the discard effluents. As a consequence, there is an enormous loss of nutrients and major environmental risks. To solve this problem, it is crucial that the waste generated is subjected to several appropriate secondary processing and valorization for the regeneration of value-added products. The marine-acquired biomolecules are found to be applicable in the agricultural, biotechnological sectors and food industries. Enzymatic, chemical, and microbial processing of fish processing waste permits the fabrication of various beneficial bioactive compounds. Method of processing employed could affect the quantitative and qualitative characteristic properties of the biomolecules extracted or recovered from these processing wastes. Thus, the present review sheds light upon the importance and available methods for processing fish processing waste and their potential applications in various fields of interest and therapeutic approaches.