Question

Refrigeration helps in food preservation by
A. Killing the germs
B. Reducing the rate of biochemical reactions
C. Destroying enzyme action
D. Decreasing the size of bacteria

Answer 1

Hint: There are two terms here namely refrigeration and preservation. Refrigeration is a process where you provide a cool environment to remove the unwanted heat from a substance. Preservation of food is the technique where you protect the food from spoiling and improve its storage life. There are three principles involved in preserving the food.

Complete answer:
We all use refrigerators in the home to store different kinds of food because it provides a very low temperature, so we think that food doesn't get spoiled. We think that food doesn't spoil because the temperature inside it is too low. This is the truth behind this. For any organism to survive and grow it needs favourable conditions i.e. they can grow only in specific temperature range with the availability of air, water, nutrients and so on. Without the favourable conditions, it doesn't grow because the biochemical reactions are slowed down within it. So, when you place the food in the refrigerator, the temperature present there is too low for any organism to grow and survive. Such low temperatures will reduce the rate at which a reaction is taking place. It doesn't completely kill or destroy an organism but can reduce its growth.

By the above explanation, the correct option is B.

Note:
The refrigeration method does not completely stop the reaction from taking place. It just ensures that the enzymatic and microbial changes in the food are considerably slowed down. Apart from refrigeration, there are other techniques to preserve food like boiling, filtration, irradiation, using antioxidants etc. The principle employed in all the techniques are different from one another. In all the cases,the reactions are not slowed down.