This can be a sign the food contains harmful microorganisms. Choose perishable foods last before checkout at the grocery. Go straight home and refrigerate or freeze the food immediately. Store canned goods in a cool, dry place for use within a year. Never put them above the stove, under the sink or in a garage or damp basement.
Bacteria multiply quickly at room temperature.
Defrost food in the refrigerator, in cold water or in the microwave just before cooking. Keep work areas clean. Wash hands, utensils and cutting boards in warm, soapy water before and after preparing food or handling raw meat or poultry. Both wooden and plastic cutting boards can be sanitized with a solution of 1 teaspoon chlorine bleach per quart of water. Divide food into shallow containers and promptly refrigerate it.