Food composition can influence microbial death rate even at the same Aw .At an Aw of 0.33, Escherichia coli counts reduced by log10 2.8 in ice cream powder, log10 4.8in dried potatoes, but by more than log10 6 in coffee. Under the same conditions, thedeath rate of Enterococcus faecalis was much less. Although the survivors remain dormant in a low Aw food, as soon as it is rehydrated, the microorganisms regain the ability to metabolize and multiply. Thus, a rehydrated food should be treated asa perishable food that, unless effective control methods are used, can be unsafe and spoiled