Quiz 3: Revision on Food Safety [NT science]

What are microbes?

• Microbes are tiny organisms around us that are too small to be seen with our eyes.

• Microbes are large organisms that can be seen with our eyes.

• Microbes are harmful substances that spoil food.

• Microbes are only found in certain types of food.

Answer explanation

Microbes are organisms, not substances. As our food is exposed to air, all food contains microbes.

Which of the following are microbes?

• bacteria

• disease

• mould

• cells

Which of the following can be used to see microbes?

• magnifying glass

• binoculars

• spectacles

• microscope

What is the action of bacteria on milk?

• Bacteria can cause the milk to turn sour.

• Bacteria make milk taste better.

• Bacteria have no effect on milk.

• Bacteria can only spoil solid foods.

What is the action of mould on bread?

• Mould can spoil bread.

• Mould makes bread taste better.

• Mould has no effect on bread.

• Mould can only grow on fruits.

What is food spoilage?

• Food spoilage is a process through which the food becomes unsafe to eat.

• Food spoilage is when food tastes better.

• Food spoilage is when food is preserved.

• Food spoilage is when food is cooked.

Which of the following is NOT a factor that affects microbial activity?

• pH

• carbon dioxide supply

• water content

• temperature

Answer explanation

The four factors that can affect microbial activity are:

• - pH

• - oxygen supply

• - water content

• - temperature

Which of the following is NOT a method to prevent food spoilage?

• lowering pH

• using high temperature

• increasing water content

• reducing oxygen supply

Answer explanation

The methods to prevent food spoilage are:

• - lowering pH

• - reducing oxygen supply

• - reducing water content

• - using higher temperature

• - using low temperature

Adding acids like vinegar into food can prevent food spoilage.

• True

• False

Answer explanation

This is called pickling.

Why does vacuum sealing help prevent food spoilage?

• It reduces the pH of the food.

• It reduces the temperature of food.

• It reduces the oxygen supply available.

• It reduces the water content of food.

Answer explanation

Vacuum sealing removes air that is in contact with food, thus reducing the amount of oxygen in contact with the food.