Abstract
The applicability of the IDF method for the detection of Staphylococcal thermonuclease (TNase) produced in cooked rice was examined. The lower limit of detection of TNase levels was 0.01μg/g in cooked rice by the IDF method. TNase was detectable at S. aureus population levels of 107/g, whereas enterotoxin was detected after 16-24 hours. The IDF method was modified by adding the sample to the Tris-buffered solution directly in the course of TNase extraction, and the supernatant was obtained by centrifugation; in addition, greater sensitivity could be obtained by increasing both the well size and the amount of the supernatant tested. The lower limit of detection of TNase levels was 0.005μg/g in cooked rice by the modified procedure.
