This method dehydrates microbial cells by plasmolysis thereby causing them to die

The correct option is Sugaring.

Here is a step-by-step educational explanation of why this is the correct answer:

1. Understanding Plasmolysis:
Plasmolysis is the process in which cells lose water in a hypertonic solution. When the concentration of solutes (like sugar or salt) outside the cell is much higher than the concentration inside the cell, water moves out of the cell via osmosis. This causes the protoplast of the cell to shrink away from the cell wall, leading to dehydration and ultimately the death of the cell.

2. How Sugaring Works:
Sugaring is a food preservation method where high amounts of sugar are added to foods (such as fruits for making jams, jellies, or preserves). The extremely high sugar concentration in the surrounding environment creates a highly hypertonic medium.

3. Effect on Microbial Cells:
When bacteria, yeasts, or molds contaminate the sugared food, the water inside these microbial cells is drawn out into the surrounding sugary environment to balance the solute concentrations. As a result, the microbial cells undergo severe plasmolysis, dehydrate, lose their cellular structure, and die. This prevents them from multiplying and spoiling the food.

4. Why Other Options Are Incorrect:

Heating: Primarily kills microbes by denaturing their proteins and disrupting cell membranes through high thermal energy, not through osmotic dehydration.
Smoking: Kills or inhibits microbes through heat, drying of the outer surface, and the deposition of chemical compounds (like phenols) from the smoke which act as preservatives.
Pasteurization: Uses mild heat to reduce the number of viable pathogens and spoilage organisms, acting via thermal denaturation of proteins rather than plasmolysis.