Question

Food is preserved at low temperature because
A. Bacterial attack is minimized
B. For easy cooking
C. For easy digestion
D. All of the above

Answer 1

Hint: The spoilage of food is a major issue that needs to be eliminated to reduce food loss. Various preservation techniques are used to preserve food and refrigeration is one of them. At low temperatures, the cellular activity of food decreases, and the respiration rate also lowers. This keeps food fresh and healthy.

Complete answer:Food preservation is a technique in which the shelf life of the food can be increased. The food can be kept away from microorganisms by utilizing the preservation techniques as they are major food spoilers. The cellular processes and respiration that occurs in cells of food material causes aging and hence leads to food spoilage. Both of these factors are inhibited by refrigeration. Refrigeration refers to introducing food items to lower temperatures so that their cellular activities decrease and bacteria find it difficult to propagate in colder conditions. Hence, this ensures food safety and freshness. The taste is enhanced and the food seems fresher.
The refrigeration method involves the removal of available heat. The temperature of the food reaches below its freezing point. This reduces water activity due to the formation of ice. Osmotic changes in cell fluid occur. Lowering of temperature slows down chemical reactions. Therefore, this inhibits the growth of microorganisms. Physical, biochemical, and microbiological contamination or degradation of food can be controlled by altering temperature.

Hence, option A is correct.

Note: Various other methods of preservation of food are canning, drying, preservation by radiation, supercooling, etc. In supercooling, the food does not go below the freezing point. Crystals are formed directly. The yield of better quality food products is obtained by supercooling. Also, undesirable effects of freezing can be avoided using this method.