11. Controlling Microbial Growth

Pasteurization is what type of microbial control method?

How does desiccation control microbial growth?

This method of physical microbial control combines the removal of all moisture with extremely low temperatures.

How does irradiation control microbial growth?

How do salts and sugars preserve foods? Why are these considered physical rather than chemical methods of microbial control? Name one food that is preserved with sugar and one preserved with salt. How do you account for the occasional growth of Penicillium mold in jelly, which is 50% sucrose?

Which of the following does not kill endospores?

a. autoclaving

b. incineration

c. hot-air sterilization

d. pasteurization

e. All of the above kill endospores.

Which of the following cannot be used to sterilize a heat-labile solution stored in a plastic container?

a. gamma radiation

b. ethylene oxide

c. supercritical fluids

d. autoclaving

e. short-wavelength radiation

Which of the following is most likely to be bactericidal?

a. membrane filtration

b. ionizing radiation

c. lyophilization (freeze-drying)

d. deep-freezing

e. all of the above