A thermal process is being used to reduce the microbial population on product contact surfaces of the packages needed for aseptic packaging of the liquid product. The spoilage microorganism has a D121 = 10 min and a z = 8°C. The microbial population on the surface is 100 per cm2 and the product contact surface area is 8 cm2 for each package. A 9D process has been recommended. a. Determine the process time for the containers at 140°C.

b. Estimate the number of containers with spoilage based on survivors on the package surface when 10 million packages have been filled.