Proteolysis and cathepsin activities in the processing of dry-cured duck

• Published in: Poultry science Vol. 93; no. 3; pp. 687 - 694
• Main Authors: Wang, D. Y., Zhang, M. H., Bian, H., Dong, H., Xu, W. M., Xu, X. L., Zhu, Y. Z., Liu, F., Geng, Z. M., Zhou, G. H., Wang, P.
• Format: Journal Article
• Language: English
• Published: England Poultry Science Association, Inc 01.03.2014
• Subjects: Animals; Avian Proteins - metabolism; Cathepsin B - metabolism; Cathepsin D - metabolism; Cathepsin L - metabolism; Ducks; Electrophoresis, Polyacrylamide Gel - veterinary; Food Preservation; Male; Muscle Fibers, Skeletal - metabolism; Muscle Proteins - metabolism; Myofibrils - metabolism; Peptide Hydrolases - metabolism; Poultry Products - analysis; Proteolysis; dry-cured duck; processing; free amino acid; endogenous enzyme activity; proteolysis
• DOI: 10.3382/ps.2013-03335
• ISSN: 0032-5791

Changes in sarcoplasmic and myofibrillar proteins, free amino acids, and cathepsin activities were measured to evaluate the contribution of cathepsins to the proteolysis of muscle proteins in dry-cured duck processing. Thirty-six dry-cured ducks were processed with the traditional method, and samples were collected at different stages. Sarcoplasmic and myofibrillar proteins were found to be degraded to some degree at different stages, whereas content of free amino acids increased from 43.9 to 133.97 mg/100 g during the whole process. Cathepsin B, D, and L activities decreased significantly, and the activities in the end product were 22.4, 26.2, and 40.5% of those in the raw material, respectively. Statistical analysis showed there were significant correlations among changes in proteins, free amino acids, and cathepsin activities. The results indicated that cathepsins are involved in the proteolysis of muscle proteins in dry-cured duck processing.