The best way to preserve vegetables is to refrigerate them. Refrigeration slows down the natural decaying process of vegetables, keeping them fresh for a longer period of time. When vegetables are refrigerated, they are stored at a low temperature which inhibits the growth of bacteria and other microorganisms that can cause spoilage. Freezing is also a good option for preserving vegetables, but it can affect the texture and taste of some vegetables. Grilling and roasting are cooking methods and do not preserve vegetables for long-term storage.