Past Exam Questions Flashcards
State the temperature range of psychrophiles
-5 degrees Celsius to 20 degrees Celsius
State the temperature range of mesophiles
20 degrees Celsius to 45 degrees Celsius
State the temperature range of thermophiles
45 degrees Celsius to 75 degrees Celsius
What is the main use of lactic acid bacteria in food production?
Making of cheese and yogurt
What is the main use of lactobacillus bulgaricus in food production?
Yogurt
What is the main use of yeast in food production?
Bread making
Define aerobic microorganisms
Microorganisms that require oxygen to survive
Define anaerobic microorganisms
Microorganisms that do not require oxygen to survive
Define facultative microorganisms
Microorganisms that can survive with or without oxygen
State one use of moulds in food production
Penicillium is used in making blue-veined cheese
State one use of yeast in food production
Bread making
State one use of large fungi in food production
Mushrooms can be used in making meals such as curries
List five conditions required for the growth of moulds
Food pH Oxygen Moisture Time Warmth
State two uses of microorganisms in food production
Penicillium mould is used in making blue veined cheese
Yeast is used in bread making
Discuss how food is needed for the growth of moulds
Moulds are saprophytic which means they feed of non-living matter
Discuss how moisture is needed for the growth of moulds
Moulds require moisture to growth
They require an a.w. (water activation) level of 0.8 or above
Discuss how warmth is needed for the growth of moulds.
Moulds are mesophilic and grow best between 20 and 45 degrees Celsius
Discuss how oxygen is needed for the growth of moulds
Moulds are aerobic which means they require oxygen to grow
Discuss how pH level is needed for the growth of moulds
Moulds grow in slightly acidic environments
Mould growth are inhibited by extremely acidic conditions
Mould growth is inhibited by alkaline conditions
Name one type of mould
Penicillium
Describe penicillium
6 points
Ascomycete 20-25 degrees Saprophytic Asexual Green-powdery mould Conidia only
How does penicillium reproduce?
Asexually
Describe how penicillium reproduces asexually
3 points
A hypha grows upwards from a mycelium
The hypha produces a conidia (chained structure made of unprotected spores)
Conidia breaks away releasing spores into the environment
Outline the uses of microorganisms in food production
Large fungi:
-some are edible e.g. truffles
Yeasts:
-used in bread and beer making
Mould:
-penicillium is used to make blue-veined cheese and -aspergillus flavus is used to make mycoprotein
Bacteria:
-lactobacillus bulgaricus is used in yogurt making
-lactic acid bacteria is used in cheese making
