Enzymatic Protein Hydrolysates of Common Carp Fish: I. Functional Properties and Molecular Weight Distribution

The present work aims to investigate the preparation of a value added product from common carp fish in the form of a protein hydrolysate. Protein hydrolysates were prepared using papain, bacterial protease, and bovine protease. The optimum conditions for proteolytic activity of enzymes were investigated. This was followed by the determination of the rate of enzymatic degradation. The effect of the enzymatic hydrolysis on the molecular weight distribution of the protein was carried out by gel chromatography on Sephadex G-100. The protein hydrolysates were examined with respect to their content of biogenic amines, then analysed for their functional properties. Protein content of fish hydrolysates ranged between 85-89%. Rate of enzymatic degradation showed that papain enzyme resulted in higher degradation of the protein than bacterial and bovine proteases, thus more solubilization of protein was achieved. Gel chromatography of the three hydrolysates demonstrated the degradation of protein with molecular weight 90,000 Dalton to peptides with molecular weight 2,500 Dalton. Amino acid analysis indicated that protein hydrolysates were rich in lysine and sulphur containing amino acids. Biogenic amines were found to be within the permissible levels. Enzymatic hydrolysis generally improved solubility and wettability of proteins.