Vinegar and Citric Acid MCQs

Question 1

Vinegar is typically produced in fed batch reactors because

Accepted Answer

a fed batch reactor can be used to maintain low ethanol concentrations

Answer

a fed batch reactor can be used to maintain low acetic acid concentrations

Answer

acetic acid bacteria tend to ferment at high ethanol concentrations

Answer

all of the above

Question 2

For the recovery of citric acid after fermentation, Ca(OH)2 is added to the slurry to

Accepted Answer

precipitate calcium citrate

Answer

precipitate calcium carbonate

Answer

precipitate calcium phosphate

Answer

precipitate calcium sulphate

Question 3

Which of the following microorganism is used for the production of citric acid?

Accepted Answer

Aspergillus niger

Answer

Lactobacillus bulgaricus

Answer

Saccharomyces cerevisiae

Answer

Streptococcus lactis

Question 4

Sugar content of the fermentation medium for citric acid is maintained at

Accepted Answer

20-25 %

Answer

10-15%

Answer

15-20%

Answer

25-30 %

Question 5

Spirit vinegar is produced from

Accepted Answer

ethanol

Answer

fruit juices

Answer

malted grain

Answer

ale

Question 6

What is the pH of the medium when sucrose is used as substrate for the production of citric acid?

Accepted Answer

3

Answer

4

Answer

5

Answer

6

Question 7

In liquid surface culture process for the fermentation to produce citric acid,

Accepted Answer

A. niger floats on the surface of solution

Answer

A. niger is used with solid substrate as sweet potato

Answer

Fungal mycelium grows through out the solution in a deep tank

Answer

both (a) and (b)

Question 8

In koji process for the fermentation to produce citric acid,

Accepted Answer

A. niger is used with solid substrate as sweet potato

Answer

A. niger floats on the surface of solution

Answer

Fungal mycelium grows through out the solution in a deep tank

Answer

both (a) and (b)

Question 9

What is the pH of the medium when molasses is used as substrate for the production of citric acid?

Accepted Answer

5

Answer

3

Answer

4

Answer

6