Valorisation of fish discards assisted by enzymatic hydrolysis and microbial bioconversion: Lab and pilot plant studies and preliminary sustainability evaluation

Abstract

The new EU fishing policies (Landing Obligation) are aimed at preventing the elimination of fishing discards overboard. These new biomasses that have to be landed from 2019 force to stablish valorisation protocols since, in most cases, they cannot be used directly for human consumption. In this context, the aim of this work was to develop an integral process based on enzyme proteolysis that permitted jointly the production and recovery of fish protein hydrolysates (FPHs), oils, bioactive peptides and fish peptones. This procedure was initially applied to ten fish discards to lab scale. FPHs of high quality in terms of soluble protein and amino acid contents, digestibility and bioactivities were obtained. The growth and metabolites productions by Pediococcus acidilactici on peptones from FPHs was also evaluated with excellent results. Pilot plant trials confirmed the results of FPHs production obtained at lab scale. Finally, a comparison with the nowadays most common use of fish biomass (fish meal production) has been made as a preliminary sustainability assessment of the proposed FPHs valorisation chain.