GREEN EXTRACTION AND CHARACTERIZATION OF GELATIN COMING FROM UNSORTED DEHYDRATED CANNED TUNA SIDE STREAMS

This study, funded by the EcoeFISHent project, describes a scalable method for the extraction of valuable proteins, such as marine gelatin and Hydrolyzed Gelatin Peptides (HGPs), but also non-collagenous proteins, in order to define future applicationsin the food, packaging, and cosmetic industries. The process starts from unsorted mixed Yellowfin tuna scraps after a patented industrial dehydration process that enhances the logistics in the valorisation of highly perishable biomasses. Materials and Methods Samples made up of raw crude heads, fins, skin, tails, and bones from Generale Conserve's (ASdoMAR®) mixed unsorted canned Yellowfin tuna processing side streams were dehydrated and milled using an industrial process patented by Themis S.p.A. to stabilize them over time as a fish biomass with a low residual humidity. Besides, microbiological activity of samples pre and post dehydration was monitored to ensure the occurred stabilization. Before gelatin extraction, the starting material was analyzed in terms of proximate analysis to assess residual moisture (AOAC 950.46B), protein fraction (AOAC 981.10), ashes (942.05) and applying Hara-Radin method for the evaluation of lipid content; moreover, amino acid composition was determined by HPLC. The gelatin extraction can be divided into three main steps: pre-treatment, extraction, and drying. In addition to the extraction of gelatin, this extraction method also allows the recovery of non-collagenous proteins and HGPs. The following analyses were proposed for the characterization of the extracted gelatin and non-collagenous proteins: their composition in residual moisture, protein, ashes, and lipid contents (AOAC Official Method 935.46), and amino acidic composition. The FT-IR analysis was applied to study the secondary structure of extracted gelatin and, as for its rheological parameters, a solution of 6.67% was prepared and the viscosity was measured at 40°C, while the gelling point was detected in a range of 5-40°C.