Foods deteriorate in quality due to a wide range of reactions including some that are physical, some that are chemical, some enzymatic and some microbiological. The various forms of spoilage and food poisoning caused by microorganisms are preventable to a large degree by a number of preservation techniques, most of which act by preventing or slowing microbial growth. These include freezing, chilling, drying, curing, conserving, vacuum packing, modified atmosphere packing, acidifying, fermenting, and adding chemical preservatives. This is section 13, Chemical food protection. We’ll look at the other food preservation mechanisms in future modules. 1 From the moment a food source is harvested in begins to deteriorate. It is estimated that 25% of the worlds food is lost to microbial decay annually. This equals more than a billion dollars per year. 2 Salting as a means of preserving foods predates written history. The Mesopotamians were known 3000 B.C.E. generally used salt to preserve meat and fish. Early Roman writers such as Cato (234‐149 B.C.E.) clearly explained the need to salt perishable meats and vegetables to preserve them. We have already seen in past chapters that salt binds water reducing water activity and also is toxic to enzymatic and DNA processes in cells. 3 Today, nearly all manufactured foods have different chemical preservatives because it makes financial sense. Food additives maintain or improve freshness, safety, nutritional value, taste, texture, or appearance. Consumers demand and enjoy a food supply that is flavorful, nutritious, safe, convenient, colorful and affordable. 4 No audio. 5 No audio. 6 In the United States, neither the Food and Drug Administration (FDA) nor the U.S. Department of Agriculture (USDA) has labeling claim rules for “natural." The FDA explicitly discourages the food industry from using the term. The Food, Drug, and Cosmetic Act prohibits labeling that is false or misleading, but does not give any specifics. The USDA's Agricultural Marketing Service has a standard for organic food, but there is no legal definition for natural foods. Despite no legal U.S. definition for natural foods, there are numerous unofficial or informal definitions, none of which are applied uniformly to foods labeled "natural". 7 So, are food chemical additives safe? 8 In 1958, the US created food additive legislation stating that the FDA must approve all food additives and ingredients that are not generally recognized as safe. The GRAS list contains food additives that have been used historically and have shown no hazards during that time. Easily recognized examples are sodium chloride, sucrose and acetic acid. Less easily recognized are many of the common food preservatives such as sodium benzoate, potassium sorbate, and calcium propionate. 9 The U.S. FDA maintains a list of over 3000 approved, generally recognized as safe, food ingredients including food.