Functional, bioactive and antioxidative properties of hydrolysates obtained from cod (Gadus morhua) backbones

Fish protein hydrolysates (FPH) have good and well documented functional properties. Peptides obtained from various fish protein hydrolysates have also shown bioactive and antioxidative activities. The aim of this study was to evaluate how storage and preparation of cod (Gadus morhua) backbones influence the yield, functionality, bioactivity (CGRP and gastrin/CCK related molecules) and antioxidative properties of fish protein hydrolysates. A series of hydrolysis trials have been carried out using backbones from cod that were initially fresh or frozen and further hydrolysed for different times (10, 25, 45 and 60 min). Use of fresh raw material significantly increased yield of dry FPH, gave lighter and less yellow powders with better emulsification properties. Longer time of hydrolysis gave higher FPH yield, increased degree of hydrolysis and decreased water holding capacity of the powders. Among the hydrolysis times tested, 25 and 45 min hydrolysis demonstrated the best emulsification properties. FPH have potential to enhance product stability by preventing oxidative deterioration. The DPPH scavenging activity showed that antioxidative activity of hydrolysates could be due to the ability to scavenge lipid radicals. The ability of hydrolysates to inhibit iron induced lipid oxidation was not influenced by time of hydrolysis. This work also shows that it is possible to obtain bioactive molecules from cod backbones by protein hydrolysis. The content of bioactive peptides (gastrin/CCK- and CGRP-like peptides) could make the cod hydrolysates useful for incorporation in functional foods.The authors wish to thank Nordic Innovation Centre (project no. 04252) and the European Community (Seafood Plus CT-2004-506359) for financial support to carry out experiments and to prepare this paper. Dr. Ekrem Misimi is thanked for the assistance in the statistical data treatment. Author Martínez Alvarez was under a Spanish fellowship of the Ministry of Education and Science.Peer reviewe