ABSTRACT
We humans have evolved from ancestors who hunted feral animals for food, later learning to cultivate grains, vegetables, and fruits. Food grown and prepared before the invention of refrigeration became commonplace in the United States was generally consumed soon after its acquisition. This was in order to avoid contact with pathogens found in deteriorating food. Decay of food is caused by microorganisms that parasitize dead plant or animal tissue. To preserve food, meat was salted or exposed to dense smoke from hardwood fi res. Vegetables and fruits were canned or stored in root cellars. With refrigeration came the ability to chill or freeze food and store it safely for short to long periods of time. In modern times, irradiation has been used to preserve food, but this method has not gained widespread acceptance due to concerns that irradiation might cause harmful changes in food, which then could affect consumers of irradiated food. The problem of pathogens in deteriorating food was theoretically overcome though refrigeration. However, the equally important health consequence of how food is prepared remained a problem. Fresh, or properly preserved, food that is contaminated with pathogens from human contact during growing, transporting, preparing, or serving food has the potential to cause human illnesses.
