Rapid detection of detergents and disinfectants in food factories

Awareness of both microbial and chemical risks in the process industry has increased through the use of HACCP (Hazard Analysis Critical Control Point) systems for hygiene assessment. Reliable detection methods are needed to ensure the cleanliness of process lines and facilities. Chemical risks in food processing include e.g. tenside residues after insufficient rinsing of the process line. Knowledge of the chemical composition of cleaning agents and disinfectants is needed before performing chemical analyses. The ATP luminescence measurement is based on an enzymatic reaction and may be significantly affected by sanitising agents and disinfectants used for cleaning. The disinfectants can reduce the activity of the luciferase enzyme, but they can also act as ATP-releasing agents of contaminating microbes. The agents disrupt the cells but preserve ATP in measurable form, and therefore the correlation with traditional culture methods can be poor. If a rapid method is used to detect ATP, a control must be used and the effect of disinfectants eliminated to eliminate sources of error. A microbiological residue-testing method, nonspecific for residues, was developed. A total of 38 commercial cleaning agents and disinfectants of various types were measured using two microbiological methods, the Vibrio fischeri photobacteria test and the Micrococcus luteus inhibition zone technique. A small study in a food factory was also performed. The results show that microbial testing methods are extremely sensitive and that a need for this type of method exists.