pure-food laws: see food adulteration.

organic food, food raised without chemicals and processed without additives. Under standards adopted by the U.S. Agriculture Dept. (USDA) in 2000 and fully effective in 2002, synthetic fertilizers and pesticides and antibiotics may not be used in raising organic foods, and the use of irradiation, biotechnology, and sewer-sludge fertilizer is also banned. Food whose ingredients are at least 95% organic by weight may carry the "USDA ORGANIC" label; products containing only organic ingredients are labeled 100% organic.

Proponents of organic food claim that it is more nutritious, safer to eat, and usually tastes better because it contains no synthetically compounded fertilizers, pesticides, herbicides, hormones, medicated feed, or antibiotics or chemicals used in food processing (see also organic farming); these claims are disputed by conventional-food growers and processors. Organic foods have become steadily more popular as the public has become more concerned about health risks associated with chemicals in food products. Organic produce is now available in many food outlets, including major supermarket chains. Organic food is generally more expensive because organic farming requires more manual labor and attention.

food pyramid or Food Guide Pyramid, diagram used in nutrition education that fits food groups into a triangle and notes that, for a healthful diet, those at the base should be eaten more frequently than those at the top. At the base of the pyramid are breads, cereals, rice, and pasta, with a recommendation that 6 to 11 servings be eaten daily. On the next levels up are the vegetable (3 to 5 servings) and fruit (2 to 4 servings) groups, followed by the dairy group (2 to 3 servings) and a group including meats, eggs, nuts, and dry beans (2 to 3 servings). Fats, oils and sweets are at the apex, with a recommendation that they be eaten sparingly.

The Food Guide Pyramid was adopted by the U.S. Agriculture Department in 1992 as a replacement for the "four food groups" scheme that had been used to teach children about nutrition since the 1950s. The four food groups (the milk group, the meat group, the bread and cereals group, and the vegetable and fruit group) had put a greater emphasis on the consumption of meat and dairy products. The adoption of the food pyramid design was delayed by debate between nutritionists (who felt that it was an effective teaching tool that demonstrated current thinking about the benefits of a low-fat, high-complex carbohydrate diet) and the meat and dairy industries (which felt that the positioning of their products among the foods to be consumed less frequently implied that those foods were unhealthful).

food preservation, methods of preparing food so that it can be stored for future use. Because most foods remain edible for only a brief period of time, people since the earliest ages have experimented with methods for successful food preservation. Among the products of early food conservation were cheese and butter, raisins, pemmican, sausage, bacon, and grain.

As scientific investigations regarding the causes of food spoilage were undertaken, they pointed the way to a wider application of methods already in use and to the discovery of new ones. Before 1860 changes in food were explained on the theory of spontaneous generation. Pasteur demonstrated that ferments, molds, and some forms of putrefaction were caused by the presence of microorganisms widely distributed in the environment. Since these microorganisms are the main cause of food spoilage, food preservation depends on rendering conditions unfavorable for their growth. Processes of preservation may be generally classified as drying, heating, refrigeration (see also frozen foods), and the use of chemicals or other particular agencies.

Drying and Heating

The most ancient method is drying, and it was employed early for fruits, grains, vegetables, fish, and meat. It was sometimes combined with parching, as in the oatmeal of Scotland or the corn of the Native American. Modern applications of this ancient device are seen in dried or dehydrated fruits and vegetables, milk, meat, and eggs. A more recent variation, known as freeze-drying, is now being used on such foods as instant coffee, meat, orange juice, and soup. The early method of drying was by direct exposure to the sun's rays; in modern industry the process is hastened by complex apparatus and by chemical agencies. The use of sugar was early combined with drying. Smoking, a method used mainly for fish and meat, combines the drying action with chemicals produced from the smoke, which form a protective coating. The process of heating was used centuries before its action was understood (see canning). One of the most important modern applications of the heat principle is the pasteurization of milk.

Preservatives

In modern food preservation, preservatives function in two ways. One is by delaying the spoilage of the food, while the other is by ensuring that the food retains, as nearly as possible, its original quality. The first method includes the use of sugar (see jelly and jam), vinegar for pickling meats and vegetables, salt (one of the oldest preservatives), and alcohol. Good wine will keep almost indefinitely, and fruit placed in a 15% to 20% alcohol solution (brandying) is well preserved. The second method includes the use of ascorbic acid (which prevents color deterioration in canned fruits), benzoic acid, sulfur dioxide, and a variety of neutralizers, firming agents, and bleaching agents. The excessive or unacknowledged use of these chemical agencies has been legislated against by most governments.

Exclusion of Air

The exclusion of air, nowadays accomplished by hermetic sealing, is an old device, formerly practiced by pouring hot oil over potted meat or fish, by coating or mixing food with melted fat, as in pemmican, or by burying vegetables in the earth or in sand. The use of melted paraffin achieves the same result. Eggs may be preserved by preventing air from penetrating their porous shells, usually by coating them with an impervious substance.

Irradiation

Irradiation has also been used successfully to destroy many of the microorganisms that might cause spoilage in food. Irradiation has been declared safe by the Food and Drug Administration and World Health Organization. Thus, despite opposition from those who fear that health hazards from its use will be discovered later, this method is gradually gaining acceptance.

food poisoning, acute illness following the eating of foods contaminated by bacteria, bacterial toxins, natural poisons, or harmful chemical substances. It was once customary to classify all such illnesses as "ptomaine poisoning," but it was later discovered that ptomaines, the products of decayed protein, do not cause illness. The symptoms, in varying degree and combination, include abdominal pain, vomiting, diarrhea, headache, and prostration; more serious cases can result in permanent disability or death.

Bacterial Food Poisoning

In general, the bacteria that cause food poisoning do not affect the appearance, aroma, or flavor of food. The most common bacterial causes of food poisoning are Salmonella (see salmonellosis), staphylococcus, Escherichia coli, Listeria monocytogenes, Shigella, and Campylobacter jejuni. The symptoms may be caused by toxins produced by the bacteria. The most serious type of food poisoning caused by bacterial toxins is botulism, which results from toxins made by the bacterium Clostridium botulinum.

Salmonella, most notoriously spread via raw eggs, develops from 6 to 72 hours after exposure. Symptoms include severe diarrhea, fever and chills, vomiting, and abdominal cramps and usually last from three to five days. Staphylococcal food poisoning is actually caused by the potent toxins that they produce. Typical sources are unrefrigerated ham, poultry, potato or egg salad, and custards. Carriers and food handlers with staphylococcal skin infections are mainly responsible for the spread of staphylococcus toxin poisoning. The onset of symptoms from such poisoning (similar to those of Salmonella infection) occurs abruptly one to six hours after ingestion of the polluted food. The illness lasts from 24 to 48 hours; fatalities are rare.

Infection with a particular strain of the usually harmless E. coli began to appear in food poisoning cases from the 1980s on, typically in raw or undercooked ground meat. Onset of symptoms comes one to eight days after eating the contaminated food. Symptoms include bloody diarrhea, nausea, and sporadic vomiting, with or without fever. It can progress to kidney failure and death, especially in children.

Listeriosis, caused by the bacterium Listeria monocytogenes, is spread in soft cheeses, undercooked meats, and prepared foods from delicatessen counters. Its onset is abrupt. Symptoms vary with the person's immune status and may include fever, muscle aches, fatigue, and nausea. The illness is especially serious for the very young or for pregnant women, who may miscarry or transmit blood infections or meningitis to the baby. In adults, the disease can progress to central nervous system complications, endocarditis, or pneumonia, and is an especially serious threat to the elderly.

Shigella is spread by contaminated food or from person to person (principally via a fecal-oral route). New strains of bacteria of the genus Shigella have been associated with food poisoning from ground meat. Symptoms include watery diarrhea, abdominal cramps, and bloody mucus in the stools.

Campylobacter enteritis is caused by either of two species of the Campylobacter bacterium. The bacterium is ubiquitous in uncooked poultry. Symptoms (diarrhea, fever, chills, headache) arise 2 to 11 days after exposure and last one to two weeks. Although usually mild, the infection can cause Guillain-Barré syndrome, a weakness of the peripheral nerves that can lead to paralysis and death.

Treatment for most bacterial food poisoning includes rest, sedation, and replacement of fluid loss if necessary. Antibiotics usually are used only in severe cases. Preventive measures in the home include thorough cooking and prompt refrigeration of meats and eggs, washing and peeling fruits and vegetables (and avoiding uncooked produce entirely if a person has a compromised immune system), washing of cooking surfaces and utensils that may have been contaminated by uncooked foods, and careful handwashing after use of the toilet.

Since the 1970s the number of food poisoning cases in the United States has gradually increased, and beginning in the 1980s more virulent organisms and more serious cases of food poisoning with complications leading to miscarriage, kidney failure, or death were observed. Some experts have attributed this to overprescription of antibiotics and the routine use of antibiotics as growth enhancers and to treat disease in livestock, practices that encourage the development of drug-resistant bacterial variants. An increase in the consumption of uncooked fresh produce has also contributed to the increase in food-borne illnesses. The increase in the number and severity of food poisoning cases have led to concern about food inspection and preparation methods, and to consideration of irradiating high-risk foods to eliminate bacterial contamination. More stringent meat inspection procedures were put in place by the U.S. Dept. of Agriculture in 1996 in response to some of these concerns, and the Food and Drug Administration approved the irradiation of meat. The vast majority of food poisoning cases, however, involve fruits and vegetables, seafood, cheese, and products, such as juices or deli salads, made with them.

Food Poisoning by Natural Poisons and Metals

Nonbacterial food poisoning may occur after eating foods that contain a naturally occurring or acquired deleterious substance. Ingestion of poisonous mushrooms or toadstools (see mushroom poisoning) may be followed in a matter of several minutes to two hours by severe thirst, abdominal cramps, diarrhea, vomiting, sweating, dizziness, confusion, collapse, coma, and, occasionally, convulsions. Poisoning may occur also after the ingestion of immature or sprouting potatoes because of the presence of solanine, an alkaloid. Mussels and clams that have fed on poisonous plankton also are a cause of food poisoning, since the poisonous substance is not destroyed by cooking. Ergot poisoning, caused by ingestion of rye grain infected with that fungus, causes damage to the blood vessels and gangrene, as well as gastrointestinal and neurologic symptoms.

It is also possible to take into the body poisons such as arsenic, lead, or mercury via foods that have been accidentally contaminated or sprayed with preservatives and not properly cleansed before ingestion. Food stored in containers lined with cadmium has been known to cause poisoning. Typical symptoms of this sort of food poisoning (diarrhea, vomiting) may occur right away; the nervous system and respiratory systems may be affected with continued exposure.

food chain: see ecology.

food adulteration, act of intentionally debasing the quality of food offered for sale either by the admixture or substitution of inferior substances or by the removal of some valuable ingredient. The Greek and Roman classics contain allusions to wine makers and dealers who colored and flavored their wine. In England as early as the 13th cent., bakers cheapened their wares or scanted the weight, and lawmakers for the first time made an effort to prevent fraudulent dealings on the part of butchers and brewers. In Great Britain in the 18th and early 19th cent., coffee, tea, and cocoa were placed under protection laws by Parliament, passed not so much in the interest of the consumer as to keep up internal revenues. About the middle of the 19th cent. chemical and microscopal knowledge had reached the stage that food substances could be analyzed, and the subject of food adulteration began to be studied from the standpoint of the rights and welfare of the consumer. In 1860 the first food law framed in the interest of the purchaser was passed. That law, lacking sufficient means of enforcement, remained largely ineffective until 1872, when administrative officials were appointed and penalties for violation provided. In the United States the federal Food and Drug Act of 1906 was the result of a long and stormy campaign led by Dr. Harvey Washington Wiley. This law defined food adulteration and the misbranding of products; it provided regulations covering the interstate movement of food and penalties for violations. The act was superseded in 1938 by the more rigorous Food, Drug, and Cosmetic Act administered since 1940 by the Food and Drug Administration (now within the Dept. of Health and Human Services). It is charged with enforcing truthful and informative labeling of essential commodities, maintaining staff laboratories, and formulating definitions and standards promoting fair dealing in the interests of the consumer. The 1938 act broadened the definitions of adulteration, misbranding, and lack of informative labeling; it provided for factory inspections; and it increased the penalties for violations. It was amended in 1958 and 1962 to define and regulate food additives and food coloring. Imported goods that violate the provisions of the act may be denied admittance to the United States and if not removed within a given time may be destroyed. The federal law controls traffic from one state to another and is supplemented by local regulations that require food handlers to be licensed, thereby discouraging the spread of disease; it provides for the inspection by health officers of meat and other foods, of restaurants, and of dairies and cold storage methods. Food may be poisonous for reasons other than deliberate adulteration; see botulism, food poisoning.

food additives, substances added to foods by manufacturers to prevent spoilage or to enhance appearance, taste, texture, or nutritive value. By quantity, the most common food additives are flavorings, which include spices, vinegar, synthetic flavors, and, in the greatest abundance, sweeteners (e.g., sucrose, corn syrup, fructose, and dextrose). Colorings are another type of additive. Most colorings are synthetic dyes, but some (e.g., chlorophyll, beta carotene, and caramel) are naturally formed chemicals. Preservatives are divided into antioxidants, such as BHT, BHA, and ascorbic acid, which help prevent fats and oils from turning rancid or fruit from spoiling, and antimicrobial agents, which hinder the growth of mold and bacteria (see botulism). Additives that help produce a desired texture include emulsifiers, which keep substances such as mayonnaise from separating, and stabilizers, including gelatin, pectin, and carrageenan, which prevent the formation of ice crystals in ice cream. Other food additives include nutrients and leavenings, such as yeast and baking soda. Food additives comprise approximately 10% (about 150 lbs) of the food consumed by the average American adult. As nutritional awareness grows, many health experts and consumers have become more vocal in their criticism of the excessive and potentially dangerous use of food additives, particularly food colorings. In the United States, the Food and Drug Administrations is responsible for testing the safety of and regulating the use of food additives.

food: see diet; frozen foods; nutrition; vitamin.

dehydrated food: see food preservation.

adulteration of food: see food adulteration.

Food, Drug, and Cosmetic Act: see food adulteration.

Food and Drug Administration (FDA), agency of the Public Health Service division of the U.S. Department of Health and Human Services. It is charged with protecting public health by ensuring that foods are safe and pure, cosmetics and other chemical substances harmless, and products safe, effective, and honestly labeled. The Food, Drug, and Cosmetic Act of 1938 and various bills since have strengthened government control by requiring prior-evidence-of-safety tests and procedures for new drugs, pesticides, and additives and colorings in foods and cosmetics. The FDA was first established in 1931; in 1940 it was transferred from the Dept. of Agriculture to the Federal Security Agency and in 1953 to the Dept. of Health, Education and Welfare, which was redesignated as Health and Human Services in 1979. The FDA consists of the centers for Drug Evaluation and Research, Biologics Evaluation and Research, Food Safety and Applied Nutrition, Veterinary Medicine, Devices and Radiological Health, and Toxicological Research. In the early 1990s, in response to criticism that its time-consuming approval processes penalized people with AIDS, it extended the classification system it uses to prioritize drugs in order to give AIDS drugs the highest priority; it also subsequently sped up the approval process for cancer drugs. Congressional legislation in 1997 mandated an overhaul of the FDA in order to speed review of new drugs and medical devices.

Food and Agriculture Organization (FAO), specialized agency of the United Nations, established in 1945. The organization is governed by a conference composed of the entire membership (189 nations plus the European Union), which meets at least once biennially, and by a council of 49 members. Each region is allocated a fixed number of seats, 33 of which are from Third World areas. It reports to the Economic and Social Council annually. Managed by a director-general, it carries out about one third of the programs of other UN development agencies. The objective of the FAO is to contribute to an expanding world economy by promoting sustainable rural development with emphasis on the poorest farmers, promoting food production and self-reliance, and raising the level of nutrition. The FAO has no mandatory powers but seeks to accomplish its purposes by making investigations, publishing reports, and organizing conferences; it offers technical aid, improves seeds, develops serums and vaccines, and aids in increasing forestry yields. The program operations are conducted by standing committees, such as those on agriculture, fisheries, and world food security. Programs are implemented at the request of the host country.

Any method by which food is protected against spoilage by oxidation, bacteria, molds, and microorganisms. Traditional methods include dehydration, smoking, salting, controlled fermentation (including pickling), and candying; certain spices have also long been used as antiseptics and preservatives. Among the modern processes for food preservation are refrigeration (including freezing), canning, pasteurization, irradiation, and the addition of chemical preservatives.

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Acute gastrointestinal illness from eating foods containing toxins. These toxins may be poisons that occur naturally in plants and animals, chemical contaminants, or toxic products of microorganisms. Most cases are due to bacteria (including salmonella and staphylococcus) and their toxins (including botulism). Some strains of E. coli can cause severe illness. Chemical poisons include heavy metals (see mercury poisoning), either from food or leached out from cookware by acidic foods. Food additives may have a long-term cumulative toxic effect. Seealso fish poisoning; mushroom poisoning.

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Sequence of transfer of matter and energy from organism to organism in the form of food. These interconnected feeding relationships intertwine locally into a food web because most organisms consume or are consumed by more than one other type of organism. Plants and other photosynthetic organisms (such as phytoplankton), which convert solar energy to food, are the primary food source. In a predator chain, a plant-eating animal is eaten by a larger animal. In a parasite chain (see parasitism), a smaller organism consumes part of a larger host and may itself be parasitized by even smaller organisms. In a saprophytic chain, microorganisms live on dead organic matter. Because energy, in the form of heat, is lost at each step, or trophic level, chains do not normally encompass more than four or five trophic levels.

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Agency of the U.S. Department of Health and Human Services. Established in 1927, it inspects, tests, approves, and sets safety standards for foods and food additives, drugs, chemicals, cosmetics, and household and medical devices. It can prevent untested products from being sold and take legal action to halt the sale of undoubtedly harmful products or of products that involve a health or safety risk. Its authority is limited to interstate commerce; it cannot control prices nor directly regulate advertising except of prescription drugs and medical devices.

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UN agency whose purpose is to improve nutrition and eliminate hunger by coordinating the efforts of governments in agriculture, forestry, and fisheries. It also assists countries through research, training, development, and field missions, and it has helped with disaster and emergency relief. The FAO was established in 1945. Beginning in the 1960s, it concentrated on developing high-yield grain, eliminating protein deficiencies, supporting rural development, and encouraging agricultural exports. In the 1980s and '90s, the FAO emphasized strategies for sustainable agriculture and rural development that were economically feasible, environmentally sound, and technologically appropriate to the skill level of the host country. The organization, which has more than 180 members, is governed by the biennial FAO conference, in which each member country, as well as the European Union, is represented. Its headquarters are in Rome. Seealso World Food Programme.

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