Abstract:

In this study, alcalase was applied for cured spent hen breast meat before air-drying ripening. The changes in
proteolysis and free amino acids in the enzymatic treatment and control groups during dry curing were investigated and
the pattern of proteolysis was examined. The results showed that alcalase could promote the protein hydrolysis of the raw
material significantly. In hydrolysate products, myofibrillar fragmentation index (MFI) increased significantly (P ＜ 0.05)
and proteolysis index (PI) exhibited a significant increase (P ＜ 0.05). At the end of curing, the contents of sarcoplasmic
and myofibrillar proteins were decreased significantly (P ＜ 0.05) by alcalase treatment as compared to the control group.
The electrophoresis results showed that the proteins with molecular weight higher than 72 kD were gradually decomposed
while those lower than 28 kD were accumulated. In addition, the content of total free amino acids (P ＜ 0.05) significantly
increased as a result of alcalase treatment, and more amino acids were involved in the subsequent decomposition reactions at
the later stage of air drying. These observations indicated that alcalase could promote further conversion of free amino acids.

Key words: spent hens, alcalase-catalyzed degradation, air drying, proteolysis, free amino acid