CHap 5- Heat & Physical measures to Destroy Microbes/ Viruses

Question 1

benefits of heat treatment

Answer 1

cost effective, reliable, safe fast, can disinfect and sterilize

Question 2

Moist Heat Methods for /destroying microbes

Answer 2

Boiling, Pasteurization, Pressurized steam (autoclaving)

Question 3

irreversibly denatures proteins

Answer 3

moist heat

Question 4

heat method that destroys most microorganisms and viruses; does not sterilize; endospores can survive

Answer 4

boiling

Question 5

heat method that destroys heat-sensitive pathogens, spoilage organisms

Answer 5

pasteurization

Question 6

Sterilization Using Pressurized Steam​; increased pressure raises temps/ kills endospores

Answer 6

autoclave

Question 7

Commercial Canning Process​ uses

Answer 7

Designed to destroy Clostridium botulinum endospores​; reduces 10^12 endospores to only 1; “12 D process”

Question 8

why is the industrial-sized autoclave aka “retort​” designed to destroy endospores is important?

Answer 8

endospores can germinate in canned food

Question 9

Less effective than moist heat; longer times, higher temperatures necessary​

Answer 9

Dry Heat

Question 10

Dry Heat methods for destroying microbes

Answer 10

Incineration/ Dry Heat Ovens

Question 11

method of dry heat sterilization that burns cells to ashes, sterilizes inoculating loop, destroys medical wastes/animal carcasses

Answer 11

incineration

Question 12

Other Physical Methods to Remove or Destroy Microbes​

Answer 12

Filtration, Irradiation , High Pressure Processing

Question 13

process extensively used to remove organisms from heat-sensitive fluids like beers/wine

Answer 13

fluid filtration/ microfilters

Question 14

remove nearly all microbes over 0.3 micrometer from air​; used in hospital rooms , airplanes

Answer 14

High efficiency particulate air (HEPA filtration )

Question 15

directly destroys DNA and damages cytoplasmic membranes​; used to sterilize medical equipments & drugs like penicillin

Answer 15

Ionizing Radiation (Gamma Rays, X rays)

Question 16

used to destroy microbes in air, water, and on surfaces

Answer 16

Ultraviolet radiation

Question 17

do not affect microorganisms, but the heat they generate can be lethal​; ovens heat food unevenly, so cells can still survive​

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Answer 17

microwaves

Question 18

process used to extend shelf life of certain food products like guacamole/ fruit juice

Answer 18

High Pressure Processing