Product Temperature (oC) Log Kills (CFU) Corn meal 35 55 75 95 4.8 ±0.2 6.9 ±0.1 < 20 CFU < 20 CFU Whey protein concentrate 35 55 75 95 1.8 ±0.2 4.3 ±0.1 5.9 ±0.2 < 20 CFU An average initial bacterial population in each sample was approximately 8.8 log CFU/g for corn meal and whey protein concentrate. Values are means + STD of three experiments with duplicate determinations

Table 2: The number of decimal reductions of inoculated populations of E. coli cells in corn meal and whey protein concentrate during twin screw extrusion processing at different temperatures.