Abstract:

Sichuan bacon with different salt contents (3%, 4%, 5%, 6% and 7% of raw meat weight, which were individually
represented by Groups A, B, C, D and E) was tested for time-related changes in non-protein nitrogen (NPN), free amino acids
(FAA), sarcoplasmic protein and myofibrillar protein during processing and storage. The results showed that NPN contents
in Groups A, B and C were higher than in other groups. The highest FAA content, 11.75 mg/g, was observed in Group C. The
degradation of sarcoplasmic protein and myofibrillar protein in large quantities occurred during salting and smoking stages,
and the myofibrillar protein with molecular weight greater than 99 kD was mainly degraded. These two proteins changed in
the same trend for Groups A, B and C, and for Group C and D. These results indicated that the protein degradation could be
restrained by salt addition, and more FAA could be produced when 5% salt was added. Lower content of salt could shorten
the time to reach the peak level of sarcoplasm protein, but delay the appearance of the peak level of myofibril protein during
storage stage.

Key words: salt dosage, Sichuan bacon, protein degradation, sarcoplasmic protein, myofibrillar protein