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Food production

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Question 19

A commercial food producer manufactures mycoprotein in an industrial fermenter. The stages of the production process are described below:

  • Step P: Sterilise the empty fermenter using superheated steam.
  • Step Q: Heat the liquid nutrient medium containing glucose and ammonium salts to 121∘C121^\circ\text{C}121∘C to kill any pre-existing microbial spores.
  • Step R: Cool the nutrient medium down to 30∘C30^\circ\text{C}30∘C.
  • Step S: Introduce a pure starter culture of the fungus Fusarium venenatum into the cooled medium.
  • Step T: Bubble sterile air through the mixture to provide oxygen and maintain constant agitation.
  • Step U: Maintain the temperature of the fermenter continuously at 28∘C28^\circ\text{C}28∘C to 30∘C30^\circ\text{C}30∘C using a water cooling jacket.
  • Step V: Harvest the fungal biomass and heat-treat it at 68∘C68^\circ\text{C}68∘C to reduce RNA levels before texturising.
a.

Identify the matching letters of the two steps that are designed to destroy or eliminate unwanted microorganisms before the starter culture is added.

[2]
b.

Explain why the nutrient medium must be cooled to 30∘C30^\circ\text{C}30∘C in Step R before the Fusarium venenatum is added in Step S.

[2]
c.

Explain what would happen to the mycoprotein production if the fermenter in Step P had not been sterilised.

[2]
d.

Explain how the rate of mycoprotein production would be affected if the water cooling jacket in Step U failed, causing the fermenter temperature to rise to 55∘C55^\circ\text{C}55∘C.

[2]
e.

Mycoprotein is highly valued as a rich dietary source of protein. State one role of proteins in maintaining a healthy human body.

[1]

Food production Questions

  1. IGCSE
  2. /Biology
  3. /Food production