Exploitation of the whole unsorted tuna side streams: extraction of valuable proteins within EcoeFISHent project

The fishery production has grown dramatically over the past few years, and as a result, disposing of the side streams that are produced has become a major environmental and economic problem to solve [1]. One of the main objectives of EcoeFISHent, a project of the Horizon 2020 Program–Green Deal (G.A. ID 101036428) [2], consists in the valorization of rejected and underused biomass coming from the fish supply chain and the sustainable extraction of high-value bioactive molecules with potential applications in nutraceutical and cosmetic industries, following the “zero-waste” concept according to the 12th Sustainable Development Goal (SDG) [3]. Many investigations are being conducted on the enzymatic extraction of proteins from fish biomasses, but almost no research has paid attention to the exploitation of unsorted, non separated fishery biomasses. The authors suggest a scalable method in order to recover valuable proteins starting from samples of unsorted mixed raw (crude) tuna scraps [4], which had previously been dehydrated using an industrially patented process [5] that improves the logistics of managing highly perishable biomass by reducing its volume and stabilizing it microbiologically, while also avoiding the laborious sorting step of tuna side streams. All the protein fractions namely, non-collagenous proteins (NCs and ALKs), gelatin (G), and hydrolyzed gelatin/collagen peptides (HGPs) were recovered in the proposed single cascade flowchart. After their isolation/purification, the protein extracts have been stabilized by different dehydrations (lyophilizing, oven-drying and spray-drying). The so obtained products were characterized in terms of proximate analysis, FTIR/molecular structure, amino acid composition, and CIELab color. Moreover, as regards G and HGPs, further analyses concerning rheological properties and antioxidant activity were performed in order to assess their potential applicability in different fields such as biomaterials, nutraceuticals and cosmetics. [1] https://doi.org/10.3390/md19020116 [2] https://ecoefishent.eu/ [3] https://www.researchgate.net/publication/348919924 [4] https://doi.org/10.3390/gels9090760. [5] https://patentscope.wipo.int/search/en/detail.jsf?docId=WO2015181769