Production and characterization of fish protein hydrolysate: Effective utilization of trawl by-catch

Abstract

ABSTRACT: This research was conducted to efficiently extract Fish Protein Hydrolysate (FPH) from Secutor insidiator using papain and proteinase K enzymes. The degree of hydrolysis was found to be 0.8 and 0.9 for proteinase and papain respectively. The proximate analysis of the prepared FPH indicated the levels of Moisture (5.95% and 4.86%), Protein (92.14% and 89.24%), Fat (0.6% and 1.02%) and Ash (6.23 and 4.79) for papain and proteinase respectively. High solubility index (75 – 80%) was observed for the pH levels of 2, 6, 7, 8 & 10 and low solubility index of 31.75% and 32.18% was observed at pH 4 for proteinase and papain respectively. The molecular weight of the hydrolysates was estimated using SDS-PAGE method. Both samples (FPH1 and FPH2) produced bands at a molecular weight of 15 kDa and the second bands lies in between 25 kDa and 75 kDa. The foaming properties were highest at pH 2 (80 – 85%) and lowest at pH 4 (10–20%). The water binding capacity was observed to be at the highest at 0.2% concentration and there was a gradual decrease from 0.4 to 1.0% concentration of FPH. The oil binding capacity was found to be high at concentrations 0.2 and 1.0% and emulsifying properties were observed to be at the maximum in pH 2 and 10. Among the two Fish Protein Hydrolysates (FPHs) prepared, FPH1 (proteinase) has comparatively better improved functional properties than FPH2 (papain).

Keywords

• Fish protein hydrolysates
• By-catch
• Trawling
• Papain
• Proteinase K