Which of the following is not a method of food preservation?

Cooking is primarily a method of food preparation rather than preservation. While it can alter the texture, flavor, and safety of food by destroying pathogens and enzymes that can lead to spoilage, it does not extend the shelf life of food in the way that other methods do.

Freezing is a preservation method that slows down the activity of bacteria and mold by turning moisture into ice, thereby prolonging the edibility of food. Canning involves sealing food in airtight containers and heating them to kill bacteria, which also extends the food's shelf life. Fumigation is a process used to eliminate pests from stored products, and it contributes to preserving the quality of food during storage by preventing spoilage due to insect infestations.

Therefore, while cooking is important for making food safe and palatable, it does not serve as a preservation method like the others listed.