Abstract: Unopened packages, containing an edible food product pre-treated with a heat shock preservation process, can be sanitized in a hospital dishwasher by a method that includes washing the package outer surface with detergent, rinsing the package surface with a solution containing a sanitizing agent, and drying the package outer surface. The method is applicable to various food products, e.g. individual milk or juice packages, distributed to patients in hospitals. Use of the method permits unopened food packages handled by the patient to be supplied to other patients without worrying that germs and contaminants might be transmitted from one hospital patient to another hospital patient.