Acta Scientiarum Polonorum Technologia Alimentaria

Abstract The efficiency of bioluminescence applied to monitor the state of hygiene in a dairy processing plant was assessed in relation to the results of conventional microbiological methods. The used blotting tests were Envirocheck Contact DC with Agar CASO medium with added neutralizers. The analysed object was the surface of a beam stirrer in a fermentation tank. Swabs were collected following tank washing and disinfection after the completion of 15 production cycles. A high degree of correlation r = 0.91 was obtained at the reliability of comparison β = 0.906. The analysis of probability of distribution confirmed the feasibility of bioluminescence. Boundary values (112 and 171 RLU) were determined for bioluminescence for three object cleanliness ranges, based on microbial counts (cfu/cm2). Over 13% surfaces were classified as conditionally clean (Alert).