Food processing is the set of methods and techniques used to transform raw ingredients into food for consumption by humans or animals. The food processing industry utilizes these processes. Food processing often takes clean, harvested or slaughtered and butchered components and uses these to produce attractive and marketable food products. Similar process are used to produce animal feed.
Food processing dates back to the prehistoric ages when crude processing incorporated slaughtering, fermenting, sun drying, preserving with salt, and various types of cooking (such as roasting, smoking, steaming, and oven baking). Salt-preservation was especially common for foods that constituted warrior and sailors' diets, up until the introduction of canning methods. These crude processing techniques remained essentially the same until the advent of the industrial revolution.
Modern food processing technology in the 19th and 20th century was largely developed to serve military needs. In 1809 Nicolas Appert invented a vacuum bottling technique that would supply food for French troops, and this contributed to the development of tinning and then canning by Peter Durand in 1810. Although initially expensive and somewhat hazardous due to the lead used in cans, canned goods would later become a staple around the world. Pasteurization, discovered by Louis Pasteur in 1862, was a significant advance in ensuring the micro-biological safety of food.
In the 20th century, World War II, the space race and the rising consumer society in developed countries (including the United States) contributed to the growth of food processing with such advances as spray drying, juice concentrates, freeze drying and the introduction of artificial sweeteners, colorants, and preservatives such as sodium benzoate and saccharine. In the late 20th century products such as dried instant soups, reconstituted fruits and juices, and self cooking meals such as MRE food ration were developed.
Because the 20th century witnessed a rise in the pursuit of convenience, food processors especially marketed their products to middle-class working wives and mothers. Frozen foods (often credited to Clarence Birdseye) found their success in sales of juice concentrates and Swanson's "TV dinners".  Processors utilized the perceived value of vbtime to appeal to the postwar population, and this same appeal contributes to the success of convenience foods today.
- Common food processing techniques include:
- Removal of unwanted outer layers, such as potato peeling or the skinning of Peaches
- Chopping or slicing, of which examples include potato chips, diced carrot, or candied peel.
- Mincing and macerating
- Liquefaction, such as to produce fruit juice
- Cooking, such as boiling, broiling, frying, steaming or grilling
- Deep frying
- Addition of gas such as air entrainment for bread or gasification of soft drinks
- Spray drying
- Extreme examples of food processing include the delicate preparation of deadly fugu fish, preparing space food for consumption under zero gravity, winemaking, hot dogs, and chicken nuggets.
Benefits of food processing include toxin removal, preservation, improving flavour, easing marketing and distribution tasks, and increasing food consistency. In addition,it increases seasonal availability of many foods, enables transportation of delicate perishable foods across long distances, and makes many kinds of foods safe to eat by removing the micro-organisms. Modern supermarkets would not be feasible without modern food processing techniques, long voyages would not be possible, and military campaigns would be significantly more difficult and costly to execute.
Modern food processing also improves the quality of life for allergists, diabetics, and other people who cannot consume some common food elements. Food processing can also add extra nutrients.
Processed foods are less susceptible to early spoilage than fresh foods, and are better suited for long distance transportation from source to shelf. Fresh materials, such as fresh produce and raw meats, are more likely to harbour pathogenic micro-organisms (e.g. Salmonella) capable of causing serious illnesses.
In general, fresh food that has not been processed other than by washing and simple kitchen preparation, may be expected to contain a higher proportion of naturally occurring vitamins, fibre and minerals than the equivalent product processed by the food industry.
Food processing can lower the nutritional value of foods. Processed foods tend to include food additives, such as flavourings and texturizers, which may have little or no nutritive value, or be unhealthy. Some preservatives added or created during processing such as nitrites or sulphites may cause adverse health effects.
Processed foods often have a higher ratio of calories to other essential nutrients than unprocessed foods, a phenomenon referred to as "empty calories". Most junk foods are processed, and fit this category.
High quality and hygiene standards must be maintained to ensure consumer safety and failures to maintain adequate standards can have serious health consequences.
Food processing industries and practices include the following:
- Meat packing plant
- Industrial rendering
- Vegetable packing plant
- Archer Daniels Midland
- General Mills
- Kraft Foods
- Tyson Foods
- Wimm Bill Dann