Green Extraction of Hydrolyzed Collagen Peptides (HCPs) Obtained from Tuna Yellowfin Side-Streams After Industrial Dehydration Process

This study is part of "EcoeFISHent"[1], a European Union’s Horizon 2020 project (Innovation Action, Grant agreement ID: 101036428) concerning the valorization of fish side-streams for the development of nutraceutical and cosmetic products, starting from previously dehydrated biomasses. The crude biomasses, provided by Generale Conserve/As Do Mar, consisting in canning tuna processing co-products, contain fishbones, fins and heads which have been mixed, avoiding the high-cost, time- and energy-consuming sorting process [2]. Subsequentially, they have been dehydrated by an industrial patented process. The dehydration step led to obtainment of powders whose low residual moisture (less than 7%) allows to stabilize this high perishable biomasses for their further extraction and valorization. The oxidation status of the so-dehydrated biomasses has been monitored by thiobarbituric reactive substances (TBARS) assay [3]. Many batches of the above-mentioned side-streams have been considered during a sampling period of 12 months. After a preliminary proximate analysis for the evaluation of residual moisture, protein, lipid and ash contents, the so stabilized powdered material has undergone an innovative extraction flowchart to obtain Hydrolyzed Collagen Peptides (HCPs), coupling ultrasounds (Ultrasound-Assisted Extraction, UAE) with commercial enzymes (i.e., porcine pepsin). HCPs under 3 kDa have been purified by membranes and freeze-dried as well as PSC. Biological activity tests have been performed (i.e., cell viability and wound healing stimulation). The HCPs extraction yields, despite the innovative matrix is not the traditional starting material of election, provided competitive yields.