Open food boxes or cans carefully so that you can close them tightly after each use. Wrap cookies and crackers in plastic bags, and keep them in air-tight storage containers. Empty opened packages of sugar, dried fruits and nuts into screw-top jars or airtight food storage containers to protect them from pests. Inspect all food containers for signs of spoilage before use. Commercially canned foods are safe to eat after long periods of storage unless they are bulging, leaking or badly rusted. Quality, however, will diminish with long term storage. Changes in flavor, color and texture may be observed and nutritional value will decrease. For best quality, use within one year. If stored longer than one year, rotate canned goods at least every two to four years.