High-pressure effects on the mechanism of accumulated inosine 5′-monophosphate

This study was conducted to determine whether the application of ultrahigh pressure could modify the content of inosine 5′-monophosphate (IMP) in fresh pork and give direct detection of each relevant enzymatic activity to affirm the enzymatic mechanism. Pressure (0-400 MPa) and time (10 min) were applied to two types of samples: adenosine monophosphate deaminase, acid phosphatase, and alkaline phosphatase in normal saline and IMP in pork tenderloin. The results showed that varied degrees of susceptibility depended upon the pressure level. The pressure of 300 MPa could promote the formation of IMP to 1250%, at which the activity of adenosine monophosphate deaminase, an enzyme catalyzing adenosine monophosphate (AMP) to IMP, was maximized. In contrast, the activities of acid phosphatase and alkaline phosphatase were suppressed at this extreme pressure, resulting in decomposition of IMP. Finally, IMP accumulated to its maximum level at 300 MPa.