Drying can work to a degree if it’s cold, but it really depends on how you dry it since vitamin c is water soluble. Anything heat dried is out. And modern sauerkraut is pasturized so that’s pretty useless for vitamin C. Finally canned preserves are canned under high heat. These industrial processes are a major reason why scurvy was so hard to treat at the beginning of the industrial revolution. Nobody could figure it out because they kept heat treating potential solutions.