McMaster University

BIO 2EE3

CHAPTER 16

1)Which one of the following foods would have the highest water activity?

1. 1. Dried beans
   2. Almonds
   3. Honey
   4. Rice
   5. Apple

2. The most common food preservation method used in US households is
   1. Freeze-drying
   2. Curing meat
   3. Heating
   4. Refrigeration
   5. Canning

3. The most common disease associated with improperly canned food is
   1. Colitis
   2. Tetanus
   3. Botulism
   4. Gastroenteritis
   5. Stomach ulcer

4. Canning is a technique used in food preservation. The food to be canned is heated to boiling for an hour
   1. And immediately chilled after boiling
   2. In the presence of high salt
   3. With a preservative added for long term storage
   4. Under acidic conditions
   5. Under pressure of 10-15 psi

5. Which of the following type of radiation may be used to sterilize food?
   1. Radio waves
   2. Visible light
   3. Long range UV
   4. Ionizing
   5. Infrared

6. What bacterium is used in the production of Swiss cheese to give it its characteristic flavor and also the holes from carbon dioxide production?
   1. Pediococcus
   2. Propionibacterium
   3. Leuconostoc
   4. Pseudomonas
   5. Clostridium

7. Vinegar production occurs through the oxidation of ethanol by
   1. Acetic acid bacteria
   2. The yeast Saccharomyces
   3. Various molds
   4. Sulfate-reducing bacteria
   5. Lactic acid bacteria

8. An example of an organism that causes a foodborne infection is
   1. Clostridium botulinum
   2. Staphylococcus aureus
   3. Campylobacter jejuni
   4. Bacillus cereus
   5. Clostridium perfringens

9. All of the following are goals of wastewater treatment except
   1. Removal of phosphorus
   2. Removal of harmful pathogens
   3. Reduction of total organic content (TOC)
   4. Enhancement of the taste of water
   5. Removal of nitrogen

10. The release of high levels of nitrogen and phosphorus into streams after wastewater treatment will result in
    1. Eutrophication of the stream
    2. Increased nutrients for the fish in the stream
    3. Water that tastes bad
    4. The production of high quality water for plant irrigation
    5. Increase in oxygen levels in the stream

11. Anaerobic digesters at wastewater treatment plants are used to
    1. Reduce nitrogen and phosphorus in wastewater
    2. Remove toxic organic pollutants
    3. Treat sludge and particulates collected during waste treatment
    4. Remove potential pathogens
    5. Treat wastewater effluent

12. Evidence of microbial food spoilage requires the presence of at least                      microbes per gram

a. 100

b. 1000

c.     10,000

d. 100,000

e. 1,000,000

13. When you add salt to meat for preservation you are
    1. Decreasing the nutrient content of the meat
    2. Decreasing the pH of the meat
    3. Increasing the pH of the meat
    4. Increasing the water activity of the meat
    5. Decreasing the water activity of the meat

14. Most milk sold in stores today has an extended shelf life primarily because of
    1. Refrigeration
    2. Tyndallisation
    3. The addition of chemical preservatives
    4. High temperature short term pasteurization
    5. Canning techniques

15. Pickling is a preservation method that uses                         to help preserve the food
    1. Heat
    2. Acid
    3. Freezing
    4. Spices
    5. Alcohol

16. Small protein molecules produced by a microorganism that adversely affect a closely related microorganism are called
    1. Bacteriocins
    2. Lysozymes
    3. Siderophores
    4. Proteases
    5. Beta-blockers

17. Which one of the following foods is not a fermented milk product?
    1. Swiss cheese
    2. Yogurt
    3. Kefir
    4. Butter
    5. Butter milk

18. The protease rennin is used in the production of
    1. Ice cream
    2. Butter
    3. Yogurt
    4. Cheese
    5. Kefir

19. Which microbe listed below causes foodborne intoxication?
    1. Shigella
    2. Salmonella
    3. Staphylococcus
    4. Campylobacter
    5. Vibrio

20. The main goal of the primary treatment phase of wastewater treatment is the
    1. Reduction of nitrogen
    2. Removal of toxic chemicals
    3. Reduction of total organic content (TOC)
    4. Removal of particulate matter
    5. Removal of pathogenic microbes

21. The gas                          is frequently recovered from anaerobic digesters at a waste treatment plant
    1. Carbon dioxide
    2. Methane
    3. Argon
    4. Hydrogen
    5. Nitrogen

22. Ozonation is a wastewater treatment used to
    1. Reduce nitrogen levels in the water
    2. Disinfect wastewater
    3. Remove organic pollutants
    4. Remove heavy materials that may be present in wastewater
    5. Remove phosphorus from wastewater

23. Which one of the following is an extrinsic factor that affects that rate of food spoilage?
    1. Skin on a fruit
    2. Nutrient content of food
    3. Water content of food
    4. pH of food
    5. Storage temperature

24. Lyophilization is
    1. Salting of food for storage
    2. Acidification of food for long term storage
    3. Sun-dried food
    4. Type of canning technique
    5. Freeze-drying of food

25. Pasteurization is a method of preservation that involves heating the liquid to                 °C for 30 min
    1. 45
    2. 63
    3. 85

d.   100

e.   121

26. Vacuum packaging inhibits the growth of microbes that
    1. Are aerotolerant anaerobes
    2. Rely on aerobic respiration for growth
    3. Are obligate anaerobes
    4. Are chemolithotrophs
    5. Rely on fermentation for energy metabolism

27. All of the following microbes play an important role in the production of fermented milk products except for
    1. Leuconostoc
    2. Streptococcus
    3. Lactobacillus
    4. Sacharomyces
    5. Lactococcus

28. The fungus Penicillium is used in the production of
    1. Cheddar cheese
    2. Limburger cheese
    3. Colby cheese
    4. Blue cheese
    5. American cheese

29. Staphylococcus aureus causes foodborne illness through
    1. The production of an enterotoxin that contaminates prepared foods
    2. A break in the skin during food preparation
    3. The production of an exotoxin after ingestion of the microbe
    4. The consumption of undercooked meat
    5. The ingestion of the microbe which grows in the large intestine to produce symptoms

30. Which of the following methods use microbial biofilms for secondary phase of wastewater treatment?
    1. Activated sludge
    2. Oxidation pond
    3. Trickling filter
    4. Nitrification tank
    5. Anaerobic digester