Comparison of redigel, petrifilm, spiral plate system, isogrid, and aerobic plate count for determining the numbers of aerobic bacteria in selected foods

Abstract

The numbers of aerobic bacteria from chicken, ground beef. ground pork, shelled pecan, raw milk, thyme, and flour (20 samples from each food) were determined by four alternative viable cell count methods (Redigel, Petrifilm, Spiral Plate System, and Isogrid) to ascertain the effectiveness of these methods in providing viable cell counts compared with the widely used Aerobic Plate Count (APC) method. The results indicated that all five methods were highly comparable (r=0.97 and higher, with the exception of Petrifilm versus Spiral Plate System, which was 0.88) and exhibited a high degree of accuracy and agreement. Thus, the four alternative methods were found to provide accurate aerobic bacterial counts of foods compared with the APC method.