Determination of some functional properties of enzymatically hydroiyzed fish protein from Sea Bass (Dicentrarchus labrax) by-products and its effect in Whiting Mince (Merlangius merlangus)

The objective of this study was the production of fish protein hydrolysate (FPH) in order to utilize sea bass (Dicentrarchus labrar) head by-product prepared by enzymatic hydrolysis using Alcalase. The aim is to improve functional properties of FPH added lean fish mince. Physico-chemical properties (e. g. emulsifying, foaming properties) of FPH were investigated at different concentrations (0.5 %, 1 %, 2.5 %) and the effect of these concentrations on texture and cooking loss in whiting mince were also determined. The measured values for degree of hydrolysis (DH) were; 27.04±0.02 % and 38.52±0.02 % at the end of 1 h and 3 h respectively. The emulsifying activity index (EAI) of FPH was significantly increased (p < 0.05) with increasing concentration of hydrolysate. Although the FPH at concentraions of 1 % and 2.5 % produced a relatively high amount of foam, these percentages generally presented low foam stability. Addition of hydroiyzed fish protein into whiting (Merlangius merlangus) mince was found to be ineffective (p < 0.05) in reducing cooking loss compared to control samples without additive. But the addition of 2.5 % of FPH, showed significantly texture softening effect (p < 0.05). The concentration of FPH is an important factor for moderate texture hardening offish mince.