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Food processing is the set of methods and techniques used to transform raw ingredients into food or to transform food into other forms for consumption by humans or animals either in the home or by the food processing industry. Food processing typically takes clean, harvested crops or slaughtered and butchered animal products and uses these to produce attractive, marketable and often long-life food products. Similar process are used to produce animal feed. Extreme examples of food processing include the delicate preparation of deadly fugu fish or preparing space food for consumption under zero gravity.

Food processing methods

Beer fermenting at a brewery.

Common food processing techniques include:

• Removal of unwanted outer layers, such as potato peeling or the skinning of peaches.
• Chopping or slicing e.g. diced carrots.
• Mincing and macerating
• Liquefaction, such as to produce fruit juice
• Fermentation e.g. in beer breweries
• Emulsification
• Cooking, such as boiling, broiling, frying, steaming or grilling
• Deep frying
• Baking
• Mixing
• Addition of gas such as air entrainment for bread or gasification of soft drinks
• Proofing
• Spray drying
• Pasteurization
• Packaging

History

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. Evidence for the existence of these methods exists in the writings of the ancient Greek , Chaldean, Egyptian and Roman civilisations as well as archaeological evidence from Europe, North and South America and Asia. These tried and tested processing techniques remained essentially the same until the advent of the industrial revolution. Examples of ready-meals also exist from pre industrial revolution times such as the Cornish pasty and the Haggis

Processed food.

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, colouring agents, and preservatives such as sodium benzoate. 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.

In western Europe and North America, the second half of 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 "TV dinners". ¹ Processors utilised the perceived value of time to appeal to the postwar population, and this same appeal contributes to the success of convenience foods today.

Benefits

More and more people live in the cities far away from where food is grown and produced. In many families the adults are working away from home and therefore there is little time for the preparation of food based on fresh ingredients. The food industry offers products that fulfil many different needs: From peeled potatoes that only have to be boiled at home to fully prepared ready meals that can be heated up in the microwave oven within a few minutes.

Microwave oven

Benefits of food processing include toxin removal, preservation, 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 de-activating spoilage and pathogenic 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 such as vitamins.

Processed foods are often less susceptible to early spoilage than fresh foods, and are better suited for long distance transportation from the source to the consumer. 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.

Drawbacks

See also: Raw foodism and Excitotoxicity

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. Vitamin C for example is destroyed by heat and therefore canned fruits have a lower content of vitamin C than fresh ones.

Tate & Lyle brand Corn Syrup being moved by tank car

Food processing can lower the nutritional value of foods. Processed foods tend to include food additives, such as flavourings and texture enhancing agents, 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.

Processing food is a very costly process, thus increasing the prices of foods products.

Performance parameters for food processing

When designing processes for the food industry the following performance parameters may be taken into account:

• Hygiene, e.g. measured by number of micro-organisms per ml of finished product
• Energy consumption, measured e.g. by “ton of steam per ton of sugar produced”
• Minimization of waste, measured e.g. by “percentage of peeling loss during the peeling of potatoes'
• Labour used, measured e.g. by ”number of working hours per ton of finished product”
• Minimization of cleaning stops measured e.g. by “number of hours between cleaning stops”

Trends in modern food processing

Health

• Reduction of fat content in final product e.g. by using baking instead of deep-frying in the production of potato chips
• Maintaining the natural taste of the product e.g. by using less artificial sweetener.

Hygiene

The rigorous application of industry and government endorsed standards to minimise possible risk and hazards. In the USA the standard adopted is HACCP.

Efficiency

• Rising energy costs lead to increasing usage of energy-saving technologies², e.g. frequency converters on electrical drives, heat insulation of factory buildings and heated vessels, energy recovery systems
• Factory automation systems (often Distributed control systems) reduce personnel costs and may lead to more stable production results

Industries

Food processing industries and practices include the following:

• Cannery
• Industrial rendering
• Meat packing plant
• Slaughterhouse
• Sugar industry
• Vegetable packing plant

See also

External links

• Hyfoma Food processing and manufacturing knowledge Portal
• Food Processing Knowledge Transfer Network
• Food Processing Magazine and Informational Website
• Food Processing Technology Portal
• Institute of Food Technologists
• University of California, Davis. Sea Grant Extension Program Academic and industry literature and a directory of food processing software
• U.S. association of suppliers to the global food, beverage and pharmaceutical processing industries

Other sources

• Fábricas de alimentos, 9th edition (in Spanish)
• Nutritional evaluation of food processing,
• Food preservation 2nd edition, by Normal W. Desrosier

References

1. ^ Levenstein, H: "Paradox of Plenty", pages 106-107. University of California Press, 2003
2. ^ STAC - Project Information Center - 03-STAC-01 - Western U. S. Food Processing Efficiency Initiative

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