11th Edition Test Bank Ch.41 Microbiology Of Food

Prescott's Microbiology, 11e (Willey)

Chapter 41 Microbiology of Food

1) Nisin ________.

A) is a small amphiphilic peptide that disrupts membrane integrity and function

B) is a food additive that blocks the growth of some Gram-positive bacteria

C) is a bacteriocin produced by some strains of Lactococcus lactis

D) All of the choices are correct.

2) A food spoilage process called ________ results in the release of foul-smelling amine compounds.

3) Temperature and relative humidity are important intrinsic factors in determining the rate of food spoilage.

4) The use of plastic film to wrap meat products can result in increased surface growth of microorganisms in part because of exposure to ________.

A) oxygen

B) N2, which comprises approximately 78% of gas in the atmosphere

C) carbon dioxide

D) water

5) Lysozyme is an important antimicrobial substance found at high levels in which food?

A) Fish

B) Eggs

C) Vegetables

D) Fruits

6) Filtration is sometimes used to remove organisms from beer because it has less effect on the flavor than pasteurization.

7) Growth of yeasts and molds will be favored in more acidic foods.

8) Which of the following can function better at lower pH?

A) Yeasts and molds

B) Bacteria

C) Viruses

D) Protozoa

9) The first person to use heating processes to preserve foods was ________.

A) Louis Pasteur

B) Jacque Monod

C) Robert Koch

D) Nicholas Appert

10) Microorganisms that grow in media with low water availability are called ________.

11) Atmosphere is important in food spoilage; high H2S tends to reduce spoilage, while high CO2 tends to increase spoilage.

12) Which of the following represents ways in which canned foods may undergo spoilage?

A) Spoilage before canning

B) As a result of underprocessing during canning

C) Leakage of contaminated water through can seams during cooling

D) All of the choices are correct.

13) A chemical that is effective in preserving foods with a low pH such as bread is ________.

A) sodium propionate

B) sodium nitrate

C) sodium citrate

D) sodium sulfite

14) Gamma irradiation has been used to sterilize certain types of foods. There are, however, certain limitations on its effectiveness. One of these is that it will only work on ________.

A) moist foods

B) dry foods

C) foods that are not in metal cans

D) It is effective with all foods.

15) Which of the following helps preserve foods by controlling microbial access to water?

A) Drying

B) Addition of salt

C) Addition of sugar

D) All of the choices are correct.

16) Pasteurization of milk ________.

A) is no longer used for food processing in the United States

B) usually eliminates all disease-causing organisms

C) is a method for sterilization of food items

D) reduces microbial growth by decreasing availability of water

17) A major chemical used to preserve meat products is ________.

A) ethylene oxide

B) propionate

C) nitrite

D) refrigeration

18) Which of the following represents a different principle for food preservation?

A) Freeze-drying

B) Addition of salt

C) Addition of sugar

D) Heating

19) The term radappertization is used to describe food preservation by ________.

A) heat

B) chemicals

C) UV irradiation

D) gamma irradiation

20) The swelling of a food-containing can is frequently due to the production of ________ by spoilage microbes.

A) oxygen gas

B) nitrogen gas

C) carbon dioxide gas

D) All of the choices are correct.

21) The conventional low-temperature holding procedure used in the pasteurization of milk involves holding the milk at 62.8oC for ________ minutes.

A) 5

B) 15

C) 30

D) 60

22) To control microbial growth in a food, one can decrease water availability by the addition of ________.

A) sugar or salt

B) gelatin

C) agar

D) formaldehyde

23) If food-borne disease transmission does not require growth of the microorganism after ingestion because the toxic substances are already present in the food as a result of previous growth, then it is referred to as a food _______.

24) If food-borne disease transmission requires ingestion of the pathogen, followed by growth of the organism, and release of toxins in the intestine it is referred to as a food-borne ________.

25) Staphylococcus aureus, once it grows in a food, produces toxins that are not usually inactivated by heating.

26) A major fungal genus that produces aflatoxin is ________.

A) Rhizopus

B) Aspergillus

C) Claviceps

D) Penicillium

27) Aflatoxins are planar, ringed compounds that interact with DNA by ________ and cause frameshift mutations.

A) substitution

B) rearrangement

C) deletion

D) intercalation

28) Clostridium botulinum and Bacillus cereus are important disease-causing microorganisms of food that cause ________.

A) infections

B) intoxications

C) cancers

D) birth defects

29) A major organism considered to cause food-borne infection is ________.

A) Salmonella

B) Staphylococcus

C) Pseudomonas

D) Bacillus

30) One of the largest meat recall in U.S. history was prompted by the discovery of contamination by ________.

A) Listeria monocytogenes

B) Clostridium botulinum

C) Escherichia coli

D) Pseudomonas aeruginosa

31) Food-borne pathogens are most commonly identified by ________.

A) polymerase chain reaction (PCR)

B) standard culture techniques

C) pulsed-field gel electrophoresis

D) None of the choices are correct.

32) Pulsed-field gel electrophoresis can be used to link a particular pathogen associated with disease outbreaks in a specific food source.

33) The process of racking, used in the production of wines, involves ________.

A) depressurizing bottles

B) addition of sulfites

C) addition of carbon dioxide

D) removal of sediments

34) The production of natural carbon dioxide by yeasts after a wine is bottled results in ________.

A) sweet wine

B) dry wine

C) champagne

D) brandy

35) The process of beer lagering involves ________.

A) carbonation

B) aging

C) distillation

D) None of the choices are correct.

36) A microorganism that has been used in the production of sour mash whiskey is ________.

A) Leuconostoc mesenteroides

B) Lactobacillus delbrueckii

C) Lactococcus lactis

D) Saccharomyces cerevisiae

37) Bread products can be spoiled by the growth of Bacillus species that produce ________.

A) gassy doughs

B) nonrising breads

C) ropiness

D) sourdough bread

38) Mashing is a process involving ________.

A) carbonation

B) protein putrefaction

C) inoculation

D) carbohydrate hydrolysis

39) Which of the following determines whether or not a wine is considered to be dry?

A) The percentage of alcohol after fermentation

B) The amount of free sugar after fermentation

C) The amount of carbon dioxide after fermentation

D) The type of grape used as a starting material

40) Streptococcus thermophilus and Lactobacillus bulgaricus contribute to the flavor of yogurt by producing diacetyl during the fermentation of lactose.

41) In all cases, it is necessary for disease-causing microorganisms to grow in a food to result in disease transmission to humans.

42) Mold-lactic fermentation results in a unique fermented milk consumed in Finland and called ________.

43) Sequential growth of microorganisms in which the growth of one organism produces environmental conditions suitable for the subsequent growth of another organism is called ________.

44) In breadmaking, yeast growth is usually carried out under ________ conditions, which results in more carbon dioxide production and less alcohol accumulation.

45) Which of the following microbial genera is used in the production of fermented dairy products?

A) Streptococcus

B) Lactobacillus

C) Leuconostoc

D) All of the choices are correct.

46) The science of wine production is called ________.

A) enology

B) rheology

C) horology

D) eurology

47) Your roommate made potato salad and then let it sit on the counter overnight, forgetting to refrigerate it. When she discovered it in the morning, she asked you whether you thought it would be safe to eat. How should you reply?

A) Yes, as long as she refrigerates it now, since the cold will kill the microorganisms.

B) Yes, as long as she refrigerates it now, since the cold will slow the growth of any contaminating microorganisms.

C) No, because refrigeration will not inactivate microbial toxins that may have been produced while the salad sat at room temperature.  

D) Yes, as long as she refrigerates it now, because any toxins produced will be destroyed by refrigeration.

E) Yes, as long as she refrigerates it now, since the cold will stop microbial growth and inactivate toxins.

48) Freezing food is an excellent preservation method because freezing readily kills most if not all microorganisms contaminating the food.

49) You may have noticed that the prepackaged deli meats you purchase in the refrigerated section of the grocery store seem to last longer than the same meats purchased freshly sliced from the deli counter. You are puzzled because the meats are identical and you expect the products at the deli to be fresher. What is the primary reason the prepackaged meats last longer?

A) The prepackaged meats are typically sprayed with bacteriophage to prevent the growth of Listeria monocytogenes, which typically causes spoilage.

B) The prepackaged meats are stored at a much colder temperature than the deli case.

C) The prepackaged meats are not handled by the deli workers.

D) The prepackaged meats have modified atmosphere packaging that has excluded oxygen gas, which would promote the growth of spoilage organisms.

50) All of the following are responsible for food safety EXCEPT ________.

A) the grower/producer

B) the wholesaler

C) the trucker

D) the retailer

E) the preparer/server

F) the consumer

G) There are no exceptions here. All parties listed are responsible.

51) Which of the following is most often used as a starter culture for the production of cheese?

A) Aspergillus species

B) Lactobacillus species

C) Rennet

D) Saccharomyces species

52) Preservation of fermented meat products is accomplished by ________.

A) the lower pH

B) pasteurization

C) the lower water activity

D) the lower pH and lower water activity

E) All of these choices are correct.

53) Which of the following is a fermented meat product?

A) Hot dogs

B) Italian sausage

C) Country-cured hams

D) Beef jerky

54) Prior to packaging, ready-to-eat meats such as hot dogs and lunch meats can be sprayed with a preparation of lytic ________ to inhibit growth of Listeria monocytogenes.

55) Why aren't foods tested for every potential pathogen before sale?

A) Tests do not exist for all potential pathogens

B) The practice is cost-prohibitive

C) Product would spoil in the time it takes to complete testing

D) All products are tested for all potential pathogens before sale.

56) Which of the following is a nucleic acid-based method used to test foods for pathogens?

A) Whole-genome sequencing

B) Real-time PCR

C) Multiplex PCR

D) All of the options listed are nucleic acid-based methods of testing food for pathogens.

57) Place the following steps of cheese production in order from first to last.

_____ Add starter cultures

_____ Ripening

_____ Pasteurize milk to remove spoilage microorganisms

_____ Salting

_____ Aging

_____ Add rennet

_____ Separate the curd from the whey

_____ Allow curds to set

58) Which of the following is a fermented food item not commonly eaten in the United States?

A) Gari

B) Green olives

C) Sauerkraut

D) Coffee

59) Which soybean product utilizes Rhizopus spp. for fermentation?