1. Which microorganism is commonly associated with the fermentation of dairy products such as yogurt?
a. Escherichia coli
b. Lactobacillus
c. Salmonella
d. Staphylococcus aureus
Answer: b. Lactobacillus
2. What is the primary purpose of pasteurization in food microbiology?
a. Enhancing flavor
b. Extending shelf life
c. Destroying harmful microorganisms
d. Improving texture
Answer: c. Destroying harmful microorganisms
3. Which microorganism is responsible for the fermentation of sauerkraut and pickles?
a. Saccharomyces cerevisiae
b. Lactobacillus
c. Clostridium botulinum
d. Aspergillus niger
Answer: b. Lactobacillus
4. What is the primary role of beneficial bacteria in the process of food fermentation?
a. Producing toxins
b. Spoiling food
c. Enhancing flavor and texture
d. Causing decay
Answer: c. Enhancing flavor and texture
5. Which type of microorganism is commonly used in the production of bread through fermentation?
a. Yeast
b. Bacteria
c. Mold
d. Virus
Answer: a. Yeast
6. What is the temperature range at which most bacteria responsible for food spoilage grow rapidly?
a. 0-5°C
b. 10-20°C
c. 30-40°C
d. 60-75°C
Answer: c. 30-40°C
7. Which food preservation method involves removing moisture from food to inhibit the growth of microorganisms?
a. Canning
b. Pickling
c. Dehydration
d. Irradiation
Answer: c. Dehydration
8. Which microorganism is used in the production of cheese?
a. Escherichia coli
b. Staphylococcus aureus
c. Lactobacillus
d. Saccharomyces cerevisiae
Answer: c. Lactobacillus
9. What is the primary concern associated with the presence of Clostridium botulinum in canned foods?
a. Mold growth
b. Spoilage
c. Formation of toxins
d. Fermentation
Answer: c. Formation of toxins
10. Which of the following is a common method of controlling the growth of microorganisms in food by lowering the pH?
a. Pasteurization
b. Pickling
c. Blanching
d. Canning
Answer: b. Pickling
11. Which microorganism is responsible for the fermentation of soybeans to produce soy sauce?
a. Bacillus subtilis
b. Saccharomyces cerevisiae
c. Aspergillus niger
d. Lactobacillus
Answer: a. Bacillus subtilis
12. What is the primary function of nitrites in food preservation, especially in cured meats?
a. Enhancing flavor
b. Inhibiting bacterial growth
c. Improving texture
d. Adding color
Answer: b. Inhibiting bacterial growth
13. Which microorganism is commonly used in the fermentation of beer and wine?
a. Lactobacillus
b. Saccharomyces cerevisiae
c. Clostridium botulinum
d. Escherichia coli
Answer: b. Saccharomyces cerevisiae
14. What is the purpose of adding preservatives like sodium benzoate to certain foods?
a. Enhancing flavor
b. Preventing oxidation
c. Inhibiting mold growth
d. Improving texture
Answer: c. Inhibiting mold growth
15. Which food preservation method involves subjecting food to high temperatures to destroy harmful microorganisms and enzymes?
a. Canning
b. Pasteurization
c. Irradiation
d. Blanching
Answer: a. Canning
16. What is the term for the study of microorganisms that cause foodborne illnesses and their prevention?
a. Virology
b. Bacteriology
c. Mycology
d. Food microbiology
Answer: d. Food microbiology
17. Which microorganism is responsible for the fermentation of cabbage to produce sauerkraut?
a. Bacillus subtilis
b. Lactobacillus
c. Saccharomyces cerevisiae
d. Escherichia coli
Answer: b. Lactobacillus
18. What is the primary goal of irradiation as a food preservation method?
a. Enhancing flavor
b. Destroying vitamins
c. Eliminating microorganisms
d. Increasing moisture content
Answer: c. Eliminating microorganisms
19. Which type of microorganism is responsible for the fermentation of cucumbers to produce pickles?
a. Saccharomyces cerevisiae
b. Lactobacillus
c. Clostridium botulinum
d. Bacillus subtilis
Answer: b. Lactobacillus
20. What is the primary function of starter cultures in food fermentation processes?
a. Enhancing color
b. Providing nutrients
c. Initiating fermentation
d. Increasing acidity
Answer: c. Initiating fermentation
21. Water activity can act as ____________.
1. An extrinsic factor
2. A processing factor
3. An intrinsic factor determines the proliferation of microbes
4. All of the above
Answer – 4, All of the above
22. Suspected colonies of Staphylococcus aureus, when grown on Baird-Parker medium, shall show____________.
1. Protease activity
2. Catalase activity
3. Coagulase activity
4. None of the above
Answer – 3, Coagulase activity
23. An undesirable change in a food that makes it unfit for human consumption is referred to as :
1. food decay
2. food spoilage
3. food loss
4. all of the above
Answer – 2, food spoilage
24. Which of the following statements are true regarding botulinal toxin?
1. is a neurotoxin
2. water-soluble exotoxin
3. is produced by Clostridium botulinum, a gram-positive anaerobic bacteria
4. all of these
Answer – 4, all of these.
25. Clostridium perfingens poison is an
1. Exotoxin
2. enterotoxin produced during sporulation
3. Endotoxin
4. enterotoxin produced during the vegetative phase
Answer – 2, enterotoxin produced during sporulation
26. Aerobic colony count (ACC) is also referred to as______________.
1. Total viable count (TVC)
2. Aerobic plate count (APC)
3. Standard plate count (SPC)
4. All of the above
Answer – 2, All of the above
27. Aflatoxin is produced by
1. Aspergillus sp.
2. Salmonella sp.
3. Fusarium sp.
4. Streptococcal sp
Answer – 1, Aspergillus sp
28. Find the incorrectly matched pair
1. Serratia – Drug addiction
2. Spirulina – Single-cell protein
3. Rhizobium – Biofertilizer
4. Streptomyces – Antibiotic
Answer – 1, Serratia – Drug addiction
29. Enumeration of microorganism refers to ______________.
1. Non-selective plating, depending on the test.
2. Either spiral plating, pour plate or spread plate of a food suspension onto a suitable selective agar
3. Either A or B
4. None of the above
Answer – 3, Either a or b
30. Botulism prevention involves
1. proper heat sterilization before food canning
2. addition of chemical preservatives
3. proper low-temperature treatment before food canning
4. all of the above
Answer – 4, All of the above
31. Thermal destruction of microorganisms follows the kinetics of
1. Zero-order
2. First order
3. Second order
4. Fractional order
Answer – 2, First Order
32. Nisin A produced by
1. Aspergillus niger
2. Acetobacter aceti
3. Lactobacillus lactis
4. Clostridium perfringens
Answer – 3, Lactobacillus Lactis
33. A plating medium consisting of _____________ is commonly used for bacterial enumeration in food.
1. Peptone, glucose, sodium chloride, agar, distilled water
2. Yeast extract, glucose, sodium chloride, agar, distilled water
3. Peptone, yeast extract, glucose, sodium chloride, distilled water
4. Peptone, yeast extract, glucose, sodium chloride, agar, distilled water
Answer – 4, Peptone, yeast extract, glucose, sodium chloride, agar, and distilled water
34. The top contaminant in the canning industry is:
1. Lactobacillus
2. Clostridium botulinum
3. Bacillus subtilis
4. Trichoderma polysporum
Answer – 2, Clostridium botulinum
35. Trichoderma harzianum is helpful for
1. Bioremediation of contaminated soils
2. Gene transfer in higher plants
3. Reclamation of wastelands
4. Control of soilborne plant pathogens by biological means
Answer – 4, Control of soilborne plant pathogens by biological means