Yes, canned potatoes are cooked prior to canning and can be eaten straight from the can or heated. A cooking and blanching process is used to kill any bacteria present on the vegetables before they are canned and vacuum sealed.
Potatoes must be heated to 240 to 250 degrees Fahrenheit before they are canned. After the heating process, the potatoes are plunged into or rinsed in cold water before being placed in sterilized metal cans. Blanching prevents the survival of Clostridium botulinum spores and microorganisms that are commonly found on vegetables. Then, a lid is placed on the can by a machine and sealed.