Microbial testing methods for detection of residual cleaning agents and disinfectants-prevention of ATP bioluminescence measurement errors in the food industry.

The ATP luminescence measurement is based on the presence of an enzymatic reaction and may significantly be affected by cleaning agents and disinfectants. In addition, disinfectants can also reduce the activity of the luciferase enzyme and also act as ATP-releasing agents. The agents disrupt the cell walls but preserve ATP in measurable form, and therefore correlation with culture methods can be poor. Therefore, if a rapid method is used to detect ATP, a control must be used for reliable results. The possible effect of disinfectants can be eliminated with a rapid test to minimize sources of error. In the present study a microbiological residue testing method that is nonspecific for residues was developed. The effects of a total of 38 commercial cleaning agents and disinfectants of various types were assessed using two microbiological methods, the Vibrio fischeri photobacteria test and Micrococcus luteus inhibition zone technique. The results show that the V. fischeri photobacteria test is very sensitive. This test can therefore be used for testing cleaning agent residues on surfaces in very small amounts. A small study was also carried out in a food factory to show applicability in processing facilities. The study showed, that a need for this type of method exists in food processing.