Strategies for the valorization of fish by-products: Fish balls formulated with mechanically separated amberjack flesh and mullet hydrolysate

The aim of the present study was to valorise fish by-products by developing fish balls obtained using mechanically separated amberjack (Seriola dumerili) flesh and the optimized fish protein hydrolysate prepared from mullet (Mugil cephalus) by-products. Shelf life of the developed products was also evaluated during refrigerated storage. The fish by-products hydrolysate (FBH) was added to the basic formulation at a concentration of 1.5%. All fish balls were packed under modified atmosphere (80% N-2/20% CO2) and stored at 4 C-degrees for 20 days. Physico-chemical and microbiological analyzes were performed. The addition of FBH significantly extended the shelf life to more than 12 days, compared to less than 8 days for conventional products. FBH also effectively prevented the accumulation of histamine and ensured that the EU limits were met throughout the 12-day (137.84 mg/kg). The addition of 1.5% of the FBH promoted a reduction of lipid oxidation, observed by volatile analysis, however, this difference was not perceived by sensorial analysis. The innovative amberjack fish balls can be considered an interesting new fish product obtained by the valorization of fish by-products (mechanically separated meat and FBH).