Evaluation of the surfaces cleaning of community raw milk cooling and storage tanks

Abstract

The sampling of the following surfaces evaluated the efficiency of hygiene procedures used in collective expansion tanks: receiving tank; connecting hose between the reception and the expansion tank; cooling tank; plastic bins; metal cans. Mesophilic aerobic counts were performed, coliforms and Escherichia coli at 30 °C, evaluation of hygiene by ATP-bioluminescence and the test 3M Clean-Trace Surface Protein Plus. The output of the expansion tank had the highest counts of aerobic mesophilic and greater disapproval by the ATP-bioluminescence method. The coliform 30 °C count was higher during the rainy season. The ATP-bioluminescence and the test 3M Clean-Trace Surface Protein Plus method showed similar approval results on surfaces where chlorine employment is usual, like at reception and in the expansion tank. In areas where the chlorine application is infrequent, such as the hose, plastic cans, and metal, the ATP-Bioluminescence method was more accurate in adopting hygienic conditions. The rainy season resulted in worse results in the evaluated areas. The lack of standardized cleaning procedures is committed to the microbiological quality of the surfaces of expansion tanks. Only the surfaces where there was the routine use of sanitizers after effective cleaning showed reduced contamination of surfaces.