Multiple Choice Questions and Answers on Vinegar and Citric Acid
Question 1 : Cider vinegar is produced from
- fruit juices
- malted grain
- ethanol
- ale
Answer : 1
Question 2 : Ethanol is oxidized to acetic acid aerobically using
- Acetobacter
- Gluconobacter
- both (1) and (2)
- Lactobacillus
Answer : 3
Question 3 : Malt vinegar is produced from
- fruit juices
- malted grain
- ethanol
- ale
Answer : 2
Question 4 : In submerged process for the fermentation to produce citric acid
- A. niger is used with solid substrate as sweet potato
- A. niger floats on the surface of solution
- Fungal mycelium grows through out the solution in a deep tank
- both (1) and (2)
Answer : 3
Question 5 : Which substrate is used in the fermentation of citric acid?
- Beet molasses
- Sucrose
- Starch hydrolysate
- All of these
Answer : 4
Question 6 : Alegar is a type of vinegar produced from
- fruit juices
- malted grain
- ethanol
- ale
Answer : 4
Question 7 : During recovery step of citric acid, calcium citrate formed is treated with which of the following acid to precipitate calcium?
- HCl
- HNO3
- H2SO4
- None of these
Answer : 3
Question 8 : Vinegar production consists of
- aerobic fermentation
- anaerobic fermentation
- aerobic fermentation followed by anaerobic fermentation
- anaerobic fermentation followed by aerobic fermentation
Answer : 4
Question 9 : What is the pH of the medium when sucrose is used as substrate for the production of citric acid?
- 3
- 4
- 5
- 6
Answer : 1
Question 10 : In liquid surface culture process for the fermentation to produce citric acid
- A. niger is used with solid substrate as sweet potato
- A. niger floats on the surface of solution
- Fungal mycelium grows through out the solution in a deep tank
- both (1) and (2)
Answer : 2
Question 11 : In koji process for the fermentation to produce citric ac
- A. niger is used with solid substrate as sweet potato
- A. niger floats on the surface of solution
- Fungal mycelium grows through out the solution in a deep tank
- both (1) and (2)
Answer : 1
Question 12 : What is the pH of the medium when molasses is used as substrate for the production of citric acid?
- 3
- 4
- 5
- 6
Answer : 3
Question 13 : Which of the following nitrogen sources is added in the fermentation medium of citric acid production?
- Ammonium salt
- Urea
- Both (1) and (2)
- Peptone
Answer : 3
Question 14 : Vinegar is typically produced in fed batch reactors because
- a fed batch reactor can be used to maintain low acetic acid concentrations
- a fed batch reactor can be used to maintain low ethanol concentrations
- acetic acid bacteria tend to ferment at high ethanol concentrations
- all of the above
Answer : 2
Question 15 : For the recovery of citric acid after fermentation, Ca(OH)2 is added to the slurry to
- precipitate calcium carbonate
- precipitate calcium citrate
- precipitate calcium phosphate
- precipitate calcium sulphate
Answer : 2
Question 16 : Which of the following microorganism is used for the production of citric acid?
- Lactobacillus bulgaricus
- Saccharomyces cerevisiae
- Aspergillus niger
- Streptococcus lactis
Answer : 3
Question 17 : Sugar content of the fermentation medium for citric acid is maintained at
- 10-15%
- 15-20%
- 20-25 %
- 25-30 %
Answer : 3
Question 18 : Spirit vinegar is produced from
- fruit juices
- malted grain
- ethanol
- ale
Answer : 3