Upcycling of fishery unsorted side-streams: a case study

It has been estimated that approximately 35 % of the global fish production is lost or wasted annually, presenting significant economic and environmental challenges. As a result of rising fish consumption, the consequent production of side streams by the fish supply chain (fishing, aquaculture, and the processing sector), namely fishery side streams, is also increasing. Two different types of side streams are commonly generated, the first is made up of whole fishes, coming from unwanted catches, by-catches, and undersized catches. The second type consists of by-products and leftovers from both filleting and/or preservation processes. If in the first case the sorting of different pieces is difficultly feasible, in the second it is feasible, but quite expensive in terms of costs, time and energy. Thus, recovering valuable components before disposal becomes the prime target in the management of solid fishery biomasses and it could be a valid alternative for their upcycling. Over the years, various conventional techniques have been utilized to exploit these biomasses, including the production of fish meal via wet pressing, fish oil through hydrophobic solvent extraction, and biofuel through esterification. Even if there has been an improvement in fish exploitation, the potential for the generation of fishery side streams remains high due to their highly perishable nature and the presence of inedible fractions. The urgent requirement to shift production systems towards environmentally sustainable alternatives has spurred the EU Commission to formulate and endorse "Blue Growth," a strategic plan designed to promote long-term sustainable growth in the marine and maritime sectors1. Many research projects have been funded at the European level, among them EcoeFISHent, which is a project funded under the Horizon 2020 Program - Green Deal (Innovation Action, Grant agreement ID: 101036428)2. This project aims at promoting circular economy practices within the fishing sector with the peculiarity to revolve around handling and valorizing of unsorted fishery by-products. In the frame of the EcoeFISHent project, a scalable method represented by a single cascade flowchart for extracting and upcycling proteins from unsorted tuna side streams (both raw and cooked) will be presented as case study3. In details, the starting biomasses were made up of a dehydrated mix of canned tuna leftovers stabilised by an innovative industrially patented procedure and the obtained extracts have been addressed to bio-packaging, cosmetic and nutraceutical applications4. References: [1] https://s3platform.jrc.ec.europa.eu/blue-growth [2] https://ecoefishent.eu/ [3] Grasso F, Méndez-Paz D, Vázquez Sobrado R, Orlandi V, Turrini F, De Negri Atanasio G, Grasselli E, Tiso M, Boggia R. Gels. 2023;9(9):760 [4] Orlandi V, Dondero L, Turrini F, De Negri Atanasio G, Grasso F, Grasselli E, Boggia R. Molecules. 2023, 17;28(22):7637