|MadSci Network: General Biology|
Most likely you can not. Ripe vegetables will spoil quickly. The best way to prolong the shelf life as long as possible is to keep the produce as cold as possible without freezing. Freezing will damage the cellular structure and hasten spoilage. The produce must also be kept dry. Increase moisture will promote microbiological growth and spoilage. The use of certain gasses may also lengthen shelf life. A combination of nitrogen and carbon dioxide is common.
Try the links in the MadSci Library for more information on General Biology.