Let the initial contamination of a liter of milk be 1OOOOO bacteria.
As we wish to pasteurize 1OOO one-liter bottles, then the total
initial number, N0 equals 1OOOOO multiplied by 1OOO = 108
bacteria, so the Log N0 = 8.
a) To reduce the surviving probability to one cell each 1OOOO
treated bottles, i.e.: Nt
, = 1/1OOOO = O.OOO1 survival, find t?
b) If the D(T) of the microorganism under consideration equals 1,
5 or 8 minutes, how long the heat treatment for the milk?