Hydrolysis as a valorization strategy for unused marine food biomass: boarfish and small-spotted catshark discards and by-products

Abstract

Discarded fish represent a serious obstacle to the sustainability of fisheries. The main outcome of analyses on the impact of discarding has been the implementation of a zero-discard policy in EU (European Union) waters. One concern in implementing this policy is finding alternatives to help fishers alleviate the costs of nondiscarding. Boarfish and small-spotted catshark are frequently discarded along the Northwest Coast of the Iberian Peninsula. Boarfish protein hydrolysates (BPHs) were prepared using a pancreas crude extract (PCE) from small-spotted catshark and compared with those prepared with commercial proteases. BPH prepared with PCE and commercial trypsin contained more protein than alcalase hydrolysates; however, the latter showed greater solubility. Emulsifying and foaming properties were higher when using bovine trypsin, followed by PCE. Antioxidant activities were similar. Fish by-products or fish with low flesh yields, usually wasted, contain valuable compounds that could be employed to obtain value-added products such as fish protein hydrolysates