A) introduce a mechanical barrier to microbial invasion.
B) reduce water activity (aw).
C) introduce a microbicide in anticipation of contaminating bacteria or fungi.
D) accomplish all of the described functions depending on the food being preserved.

A) weak acids.
B) basic substances.
C) lyophilization.
D) irradiation.

A) hemorrhagic diarrhea.
B) liver failure.
C) brain damage.
D) hemorrhagic diarrhea, liver failure, and brain damage.