The preservation of food through ‘ Cold sterilization’ involves

The correct option is Radiation.

What is Cold Sterilization?
Sterilization is the process of destroying or eliminating all forms of microbial life, including bacteria, viruses, spores, and fungi. Traditional sterilization methods rely on high heat (thermal sterilization), which can damage the quality, texture, nutritional content, and flavor of food products.
To preserve food without these undesirable changes, "cold sterilization" is used. This refers to sterilization techniques that do not rely on heat to eliminate microorganisms, allowing the food to remain cool and preserve its fresh characteristics.

Why Radiation corresponds to Cold Sterilization:
1. Mechanism of Action: Food irradiation uses ionizing radiation, such as gamma rays, X-rays, or electron beams. These high-energy waves pass through the food and break chemical bonds, directly damaging the DNA of pests, food-borne pathogens, and spoilage microorganisms. Without functional DNA, these organisms cannot reproduce or survive.
2. Temperature Preservation: Because this process does not rely on thermal energy to destroy microbes, it does not cause a significant rise in the temperature of the food. The food remains at or near its ambient temperature throughout the process, hence the term "cold" sterilization.

Evaluating the Other Options:
- Dehydration: This involves removing water from food, which preserves it by stopping microbial growth, but it is not a sterilization technique and often requires heat.
- Lyophilization: Also known as freeze-drying, this is a low-temperature dehydration process. While it uses cold temperatures, its main purpose is drying and preservation, not complete sterilization.
- Refrigeration: This process only lowers the temperature of the food to slow down microbial growth and enzymatic activity. It does not kill all microorganisms, meaning it does not sterilize the food.