Question

Solutions hypertonic to bacteria and fungi are used for food preservation. For instance, jams and jellies are hypertonic with sugar, and pickles are hypertonic with salt. How do hypertonic solutions kill bacteria and fungi that would otherwise spoil these foods?

Answer 1

Answer: Hypertonic solutions, create an environment where food's cells dehydrate preventing the growth of bacteria and fungi. Also, these solutions could create an extreme environment and would kill microbes or limit their growth.

Explanation:

Osmosis is the movement of water through a semipermeable membrane from an area of ​​low solute concentration to one of higher solute concentration to establish an equilibrium. The solutes are solids that dissolve in water and form ions, such as salts (NaCl) and sugars, these solutes are also found the cell’s cytoplasm.

Cells in food have a cell membrane, which allows the net flow of water inside or outside the cell through the osmosis process, depending on the amount of solute in the medium and the amount of solute in the cell’s cytoplasm, this is called osmolarity. A hypertonic solution is a solution with a higher concentration of solutes in the extracellular fluid than on the inside, which means there is a high osmolarity, therefore, water will move out of the cell, causing it to shrink and dehydrate. When water leaves the cell, the growth of fungi and bacteria is prevented from preserving the food. Also, a high hypertonic environment could kill microbes or slow their ability to reproduce.