Food Preservation Basics
The term “food products manufactured in the United States” covers a wide range of categories. The food products generally manufactured in the United States are those produced by U.S. corporations, which are required by law to use the United States patents on the products they make. It is important that when you buy any type of food from a grocery store, health food store, or a grocery chain that you know what country the product was made in. This will help you determine if it has been processed in a way that violates U.S. patent laws.
There are two general types of food processing: extrusion heating and modified atmosphere heating. Extrusion heating involves passing hot water through a heated tube and cooling it down; the cooled water is then used to make the food product. Modified atmosphere heating involves adding oxygen molecules to the food as it is heated so that some of the nutrient losses from processing are eliminated.
The majority of food products produced in the United States are produced by extrusion heating. The most popular extruded food items are beef and dairy products, such as cheese and milk, as well as poultry and fish. Some examples of extruded food products include ice cream, sherbets, frozen dinners, sausage, pasta sauce, tuna fish and other seafood, fruit juice, potatoes, vegetables, breads, rice, condiments, and meat. These foods are all cooked in either a gas or electric frying pan.
Some of the more common modified atmosphere heat processes include baking, canning, and freezing. Baking food products, such as breads and cookies, are typically produced using a temperature and/or time process. When using a time process, the foods are cooked at various temperatures to produce various results, including crisping, burning, defrosting, steaming, baking, and broiling. Canning food products, which include all types of food, such as canned fruits and vegetables, and tuna, salmon, meats, and chicken is typically done with a pressure canner. Freezing food products, which may be meat, fish, poultry, and dairy, are typically done with a dehydration process.
The final type of food processing that we will discuss is called ohmic heating. Ohmic heating involves utilizing electromagnetic waves to speed up the rate at which heat is absorbed and transferred, and thus speed up the heating of food. Foods which have undergone this type of treatment, such as breads and cereals, can retain much of their vitamins and nutrients. The heat energy used to perform this heating process is usually from an electricity source or sometimes, they are powered by solar or geothermal sources.
One of the oldest methods of preservation is salting. Salting is usually used to preserve dry grains such as barley and wheat. Salting is commonly performed over months to years, depending on the size of the grain. Most foods that are preserved using salting methods are hardy in comparison to other methods of preservation. Examples of hardy foods include gooseberry soup and salmon.