STM3183 Low Temp Part1

What is the main function of low temperature preservation in food?

• Increase enzymatic activity
• Reduce microbial growth and enzymatic reactions
• Increase microbial activity
• Improve respiration rate

Which temperature is generally recommended by the FDA for food refrigeration?

• 2°C
• 4°C
• 8°C
• 6°C

Which type of microorganism can grow at chilled temperatures and may cause spoilage?

• Mesophiles
• Psychrophiles
• Thermophiles
• Anaerobes

What does vacuum cooling primarily rely on to remove heat from produce?

• Evaporation of water under high heat
• Lowering air temperature
• Contact with metal plates
• Sudden freezing

Which refrigerant is used in cryogenic cooling systems?

• Ozone gas
• Liquid nitrogen or dry ice
• Steam
• Cold air only

What is the latent heat of fusion for ice?

• 120 kJ/kg
• 334 kJ/kg
• 540 kJ/kg
• 200 kJ/kg

Why should tropical fruits like bananas not be chilled below 10°C?

• They will ripen faster
• Chilling injury occurs
• Loss of sweetness
• They lose color only

Which equipment cools produce by spraying or immersing in chilled water?

• Blast chillers
• Hydrocoolers
• Plate freezers
• Cryogenic tunnel

What physical property of ice makes it efficient in preserving fish?

• Its density is higher than water
• Its latent heat can be transferred quickly
• Its freezing point is high
• It maintains oxygen supply

Which of the following does NOT freeze well?

• Frozen peas
• Whipping cream
• Carrots
• Cottage cheese (uncreamed)