Which of the following is a recognized method of food preservation?

Canning is a recognized method of food preservation that involves sealing food in airtight containers and heating them to kill bacteria and enzymes that could cause spoilage. This process not only extends the shelf life of the food but also helps retain its nutritional value, flavor, and texture. The high heat during canning ensures that harmful microorganisms are eliminated, creating a vacuum seal that prevents new bacteria from entering.

While roasting, marinating, and boiling are techniques used in food preparation, they do not serve the primary purpose of preservation in the same way canning does. For instance, roasting involves cooking food with dry heat, which can enhance flavor but does not significantly extend shelf life. Marinating can help flavor and tenderize food but does not effectively prevent spoilage over time. Boiling, while it can kill some microorganisms, does not create airtight conditions or long-lasting preservation like canning. Thus, canning stands out as a specific, recognized preservation method.