Moulds and yeasts belong to the
Answer: C
Both are eukaryotic fungi, moulds growing as filaments and yeasts as single budding cells, and both tolerate drier and more acid conditions than most bacteria. That tolerance is why they dominate the spoilage of dry and acid foods.
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Spoilage organisms reach a food chiefly from
Answer: D
Correct answer: air, soil, water and handling
Contamination is environmental. Organisms arrive on the raw material from soil and water, from the air of the processing area, from equipment surfaces and from the hands of the people handling the food. Recognising this is what makes hygiene, sanitation and process design the substance of food microbiology.
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Refrigeration of food
Answer: A
Correct answer: slows microbial growth without stopping it
Chilling reduces metabolic rate but does not sterilise, and the psychrotrophs - Listeria, Yersinia, Pseudomonas and others - continue to grow slowly at refrigeration temperatures. Refrigeration therefore extends shelf life by days or weeks rather than indefinitely, and does not make an unsafe food safe.
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Thorough cooking of a food destroys
Answer: B
Ordinary cooking temperatures kill vegetative bacteria, yeasts and moulds, while bacterial spores can survive and germinate later if the food is held warm. Some toxins are heat stable as well, so cooking cannot undo every hazard.
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Foods are best stored dry because moisture
Answer: C
Correct answer: allows microorganisms to grow
It is available water that governs microbial growth, and drying is one of the oldest preservation methods for exactly that reason. Moisture also promotes chemical deterioration and insect activity, but the microbiological risk is the primary one and the reason dry goods are kept in sealed containers.
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Stock rotation on the principle of first in, first out is intended to
Answer: D
Correct answer: use older stock before it deteriorates
First in, first out means the oldest stock is placed at the front and used first, so that nothing is left at the back to pass its date. Reversing the order - putting the newest at the front, as the distractor describes - is precisely the practice the rule exists to prevent.
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Raw and cooked foods are kept separate in order to prevent
Answer: A
Correct answer: cross-contamination of the cooked food
Raw meat, poultry and vegetables carry pathogens that cooking would destroy, but cooked food receives no further heat treatment. If the two meet, by contact, by dripping or through a shared board or knife, the organisms are transferred to a food that will be eaten as it is. Separate storage, equipment and preparation areas break that route.
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Frozen food should be thawed
Answer: B
Correct answer: in a refrigerator rather than at room temperature
Thawing at room temperature warms the outside of the item into the growth range long before the centre has thawed, so organisms multiply on the surface while the middle is still frozen. Thawing in a refrigerator is slower but keeps the whole item below growth temperature throughout, and it also catches the drip.
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Cooked food that is to be kept should be cooled
Answer: C
Slow cooling holds the food in the range where surviving spores germinate and grow, which is the classic cause of Bacillus cereus and Clostridium perfringens illness. Dividing it into shallow containers is the usual way to cool it fast.
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Canning preserves food by
Answer: D
Heat destroys the organisms present and the seal prevents recontamination, so the product is stable at room temperature for years. Low-acid foods need the higher temperatures of pressure processing to deal with spores.
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