Chapter 12 - Microbiology of Food & Water

Question 1

_____ ________ can reduce the amount of food we have available for consuming.

Answer 1

food spoilage

Question 2

Food ____________ methods can make food last longer without spoiling.

Answer 2

preservation

Question 3

What does the contamination of food and water by microbes cause?

Answer 3

human diseases

Question 4

What foods easily support microbial growth and spoil fast (salad, fresh meat)?

Answer 4

perishable foods

Question 5

what foods don’t spoil as quickly (nuts, potatoes)?

Answer 5

semi-perishable foods

Question 6

what foods remain edible for long periods (flour, sugar, dried beans)?

Answer 6

non perishable foods

Question 7

likelihood of spoilage is related to _________ (food properties) and _________ (storage environment) factors.

Answer 7

intrinsic, extrinsic

Question 8

_________ factors:
water availability
osmolarity
nutrient content
pH and buffering capacity
antimicrobial constituents
biological structure (rinds + shells)

Answer 8

intrinsic

Question 9

___________ factors:
temperature
humidity
presence + concentration of gases

Answer 9

extrinsic

Question 10

What is an example of food spoilage being desirable?

Answer 10

milk changing to form cheese, yogurt, butter, etc.

Question 11

aw=

Answer 11

water activity of food

Question 12

reduction of water activity of food:
______ food out or by adding _______ (salt/sugar)

Answer 12

drying, solutes

Question 13

Control of temperature:
Heat-treatment process that destroys pathogenic microorganisms in certain foods.

Answer 13

pastuerization

Question 14

control of temperature:
Process of cooling and heating combined with pressure to eliminate endospores.

Answer 14

canning

Question 15

Milk Pasteurization; heating at 63° C (145° F) for 30 minutes

Answer 15

low temperature hold (LTH)

Question 16

Milk Pasteurization; heating at 72° C (161° F) for 15 seconds.

Answer 16

high-temperature, short-time (HTST)

Question 17

Milk Pasteurization; heating at 138 to 150° C (280 to 304° F) for 2 seconds or less.

Answer 17

ultra-high temperatures (UHT)

Question 18

• bacteriocins (nisin)
• lactic acid
• acetic acid (vinegar)

Answer 18

natural antimicrobial preservatives

Question 19

• sodium benzoate
• propionate
• sorbates
• sulfur dioxide
• nitrites

Answer 19

artificial preservatives

Question 20

Exposure to radiation, commonly used to reduce microbial contamination of food and surfaces.

Answer 20

irradiation

Question 21

Irradiation that does not penetrate materials well, so its use is limited to surface sterilization.

Answer 21

non-ionizing radiation (UV)

Question 22

stronger, more penetrating radiation used for pasteurization and sterilization of foods.

Answer 22

ionizing radiation (gamma and x-rays)

Question 23

__________-___________ _________ (___) = vacuum packing/ taking the oxygen out.

Answer 23

modified-stmosphere packaging (MAP)

Question 24

______ technology = combining more than one approach to food preservation.

Answer 24

hurdle

Question 25

_______ ________ of microbes are added to food to begin the fermentation process.

Answer 25

starter cultures

Question 26

_______ ____ _________ (___) are used to produce cheese + yogurt.

Answer 26

Lactic Acid Bacteria (LAB)

Question 27

What form of fermentation is commonly used in Asia to produce products like Miso, tempeh, soy sauce and sake?

Answer 27

fermentation with mold

Question 28

Vinegar is produced by the fermentation of _______ by acetic acid bacteria into _______ ____.

Answer 28

ethanol, acetic acid

Question 29

Illness caused by ingestion of food containing microbial exotoxins.

Answer 29

foodborne intoxication

Question 30

Disease caused by the ingestion of live pathogens that actively multiply within the body.

Answer 30

foodborne infection

Question 31

Only about __% of the water found on Earth is freshwater.

Answer 31

3

Question 32

_________________= an increase in the concentration of nutrient leading to rapid growth of autotrophic populations (mostly algae).

Answer 32

eutrophication

Question 33

A goal of wastewater treatment is to reduce inorganic compounds that contain nitrogen and phosphate to prevent ________________.

Answer 33

eutrophication

Question 34

The physical removal of large objects from water

Answer 34

pretreatment

Question 35

the physical removal of sediments and grease that form primary sludge from water.

Answer 35

primary treatment

Question 36

uses trickling filter + activated sludge unit to form complex biofilms that break down organic compounds over time.

Answer 36

secondary treatment

Question 37

not always used, filtration method

Answer 37

tertiary treatment

Question 38

chlorination, UV light exposure, or ozonation

Answer 38

disinfection

Question 39

clumps of biomass of adsorbed material + biofilm microbes

Answer 39

flocs