ADULTERATION OF FOODS

HISTORY AND OCCURENCE

Introduction

Food is a basic prerequisite for human survival and also for social and economic welfare and progress. Problems related to food have varied from one period of history to another, from continent to continent, and from country to country. The problem of food adulteration has been a major one and the protection of the consumer has occupied the attention of civil authorities from ancient times.
Food is considered adulterated if it contains poisons or other substances which may render it injurious to the health of the consumer, or if it contains filth or it is decomposed; if it contains a coloring agent or other food additive, that is not approved or contains materials that disguise inferior quality; if any important constituent has been wholly or in part abstracted or any specified ingredient has been substituted by a nonspecified ingredient; if it contains any substance that increases its weight and bulk or changes its strength to improve appearance. A food is misbranded if it is illicitly labeled or it is a food for which standards of identity have been written and it fails to comply with these standards.

History

Food has been liable to adulteration to a greater or lesser extent since very early times. Mosaic and Egyptian laws made provision for preventing contamination of meat, while several centuries before the time of Christ India had regulations prohibiting the adulteration of grain and edible fats. Athens had its public inspector of wines. Adulteration was also common during the Roman period. Evidence for this is given in Apicius’ famous cookbook (De Re Coquinaria). During the Middle Ages in England, pepper and other costly spices imported from the east were adulterated by mixing with ground nutshells, local seeds, and olive pits. Between the 13th and 16th centuries, bread, wine, beer, spices, and valuable natural coloring materials were often adulterated. In England in 1319, a meatmarket overseer succeeded in putting a butcher in the pillory for selling unsound beef. Wines were ‘sophisticated’ (adulterated) with burnt sugar, juices, starch and gums, and other substances. Such practices may have reduced the quality of the wine but they were not injurious to health. After the 18th century, however, food adulteration became dangerous. Vinegar was often adulterated with sulfuric acid, wine with preservatives containing lead salts, green vegetables in vinegar with copper (to improve color), essential oils with oil of turpentine, confectionery products with colorings containing lead and arsenic, chocolate with Venetian red (ferric oxide), and red pepper with vermilion (mercury sulfide). ‘Black extract’, obtained by boiling poisonous berries of Cocculus indicus in water and concentrating the fluid, was used in beer. This extract imparted flavor, but also narcotic properties and intoxicating qualities to the beverage. Bread was not only the basic item of diet for many centuries but also the one most subjected to adulteration. The incorporation of sieved boiled potatoes, chalk, or bone ashes in the flour was a common fraudulent practice, but the most serious example was the addition of alum, which whitened flour of inferior quality. Recipe books of the 18th century contain instructions, which today would cause alarm. The recipe for preserving green color in pickles is characteristic: ‘To render pickles green, boil them with a halfpenny or allow them to stand for 24 hours in copper brass pans.’

It is not surprising that records of that period list a number of deaths from copper poisoning. Frederic Accum, writing from London in 1820,gives a vivid description of the adulteration of bread, alcoholic drinks, tea, coffee, and many other foods. Accum claimed that: ‘Indeed, it would be difficult to mention a single article of food which is not to be met with in an adulterated state; and there are some substances which are scarcely ever to be genuine.’ Even if these accusations are somewhat overstated, the seriousness of intentional adulteration of food, which prevailed between 1800 and the early 1900s, is undisputed. The second decade of the 19th century marks the beginning of the second period in the history of food adulteration. In the first period (ancient times to about 1820) food was procured from small enterprises and individuals who were, to a certain extent, responsible for their own transactions. In the second period (early 1800s to 1900s), the methods of food production changed significantly. Large-scale food production became necessary because of the industrial revolution, which led to a move of population from country to city. This created conditions that were conducive to large-scale adulteration of food. In the second half of the 19th century the first publicly supported analytical laboratories for food inspection were established in Germany and the USA. Intentional adulteration of food remained a serious problem until the beginning of the 20th century. Regulatory pressures and the effectiveness of analytical methods reduced the frequency and magnitude of food adulteration. Further improvements have been achieved up to the present time and, owing to strict legal standards and also to the growth of an increasingly critical public, deliberate adulteration in industrialized countries has become less serious. Of course, fraudulent practices still continue in most countries, especially those which lack adequate means to insure that laws and regulations are enforced.

Food Additives

The excessive use of additives and the use of nonpermitted ones present a serious threat to food safety. It could be argued that a fourth phase of food adulteration began some 40 years ago, when foods containing chemicals became prevalent in the diet. Since then, we have moved gradually from an outrage over fraud, sometimes practiced with dangerous substances, to a growing concern over the more subtle toxic effects of common chemicals added to food to assist manufacture and storage. As a result, there has been a shift in focus from food adulteration to safety of food, and to a different approach which emphasizes not only evaluation of the food in its entirety, but also evaluation of individual components. Current legislation relating to food additives provides statutory lists of all permitted additives which may be used and, where appropriate, the maximum levels for their use. Nevertheless, as the food industry becomes increasingly sophisticated and relies more and more on the use of additives, many consumers believe that governments are unable to control the situation and that preservatives, antioxidants, colorings, flavor or texture modifiers, and other chemicals are and always will remain a potential hazard.

Food Legislation

The use of government regulatory powers to control the purity and safety of foods is very old but the first serious efforts to regulate malpractice took place only in the 19th century. The first general food laws were passed in the UK in 1860. Accum’s book, A Treatise on Adulteration of Food and Culinary Poisons (1820), aroused the indignation of the British public.
In 1850, ThomasWakley, editor of the Lancet, established an Analytical Sanitary Commission under the direction of Arthur Hill Hassal, the first man to investigate food adulteration from a scientific point of view. He turned the microscope into a weapon in the detection of adulterants. The Commission’s reports, published in the Lancet from 1851 to 1854, led to the formation of a parliamentary committee to investigate food adulteration and, in 1860, to the passage of the world’s first Food and Drink Act. This law made it a criminal offence to sell adulterated food and drink. It also established the appointment of public analysts to examine foodstuffs produced throughout the country. In 1866, a second country, New Zealand, passed pure food legislation and, in 1874, Canada passed the Food and Drug Law.
In the 20th century, new regulations were developed in industrialized countries, and old regulations were repeatedly updated, taking into account the advice of governmental and international committees. Modern food law establishes and maintains standards for the composition of food, controls the use of additives and extent of contamination, controls packaging materials and unsanitary practices in the production of food, and restrains unwarranted and misleading claims and advertisements. Effective food surveillance systems have also been developed which insure that there is a constant supply of the right kind of food to keep people properly fed and that the food we eat is wholesome as a result of strict adherence to national and international law. The current worldwide access to data and information through the internet may soon reveal that administrative traceability can be successfully used to monitor the sale of fraudulent food products in the global market of the 21st century.

International Standards

The Food and Agriculture Organization (FAO), the World Health Organization (WHO) and the Joint Codex Alimentarius Commission are concerned with the safety of food and food ingredients. The aims of the Codex Alimentarius include protecting the health of the consumer and insuring fair practices in the food trade, coordination of all food standards work, determining priorities and initiating, guiding, and finalizing the preparation of food standards. There are published recommended international standards for individual foods (sugars, edible oils, canned fruits and vegetables, processed meat, fish products, cocoa products, etc.), as well as provisions with respect to food hygiene, food additives, contaminants, and labeling. The key role of the Codex Alimentarius in developing international food standards was recognized when the World Trade Organization (WTO) was set up in 1995. The WTO agreements accept the Codex Alimentarius standards and this enhanced status has raised the profile of the activities of the Codex. However, the impact of WTO on the Codex is not yet clear and fears have been expressed that the body may lose its ability to take decisions based strictly on science. All of the standards are detailed specifications, most of which require analytical methods for their realization. This task is backed by other standardizing organizations such as the International Union of Pure and Applied Chemistry (IUPAC), the International Standards Organization (ISO), and the Association of Official Analytical Chemists (AOAC), which are involved in the development of methods of sampling and analysis. These organizations consult with the various international bodies representing individual commodity interests, such as the International Dairy Federation (IDF), the International Association for Cereal Chemistry (ICC), the International Olive Oil Council (IOOC), the International Office of Cocoa and Chocolate (IOCC), and others.

European Union Laws

In the European Union (EU), a huge market with a population of 320 million, a programme of food law measures has been designed to create a single European market in foodstuffs. The laws of the community are expressed in the form of regulations and directives. Regulations, made under Article 43 of the Treaty of Rome, are binding on all member states and are directly applicable. The directive has no force of law in a member state until it is incorporated into the legislation of that country. Dates are prescribed in directives to insure compliance within the time stated. Some of the rules and specifications of the EU directives rely on Codex Alimentarius or other international guidelines. The Community is also laying down tougher rules for food analysis which laboratories must adopt. Bringing a multitude of national laws into line with a common objective is a difficult task but food legislation at EU level is expected to deal successfully with questions such as protection of public health, consumer information, and fair-trading. The member states of the EU have speeded up harmonization, since their governments are aware that outdated legislation can no longer act as a basis for competition in this large market. Council directives 89/397/EEC and 93/99/EEC laid down uniform general rules for the official control of foodstuffs and also for laboratories entrusted by the member states to carry out food inspection and analysis. Since 1993 coordinated food inspection programs among the responsible authorities in member states were also set up to establish compliance with food legislation and insure that food is fit for consumption. In July 1996, the so-called Black List Anti-Fraud Regulation came into effect in the EU. This regulation aims to reduce fraud within export refund and intervention measures by intensifying inspection. Those found to have committed a fraud are excluded from EU funds for at least 6 months.

Regulating the Safety of Food in the USA

In the USA there were no food regulation laws prior to the 1900s. At that time food companies could add anything to their products. In 1902, the Director of the Bureau of Chemistry in the US Department of Agriculture (USDA), Harvey Wiley, who was the leader of a campaign against food adulteration, set up a group of male volunteers to evaluate the safety of common food preservatives and ingredients. This group became known as the Poison Squad. At about the same time the Poison Squad was formed, Upton Sinclair wrote a book, The Jungle, dealing with the unsanitary conditions of the Chicago meat-packing industry. This crusade resulted in the passage of the Pure Food and Drug Act in 1906: this Act defined food adulteration and made the distribution and sale of adulterated foods and drugs illegal. These early efforts of the Poison Squad marked the beginning of food toxicology and provided impetus for the regulation of substances added to foods. In 1931, the Food and Drug Administration (FDA) was formed as a separate unit of the USDA to administer the law. This agency regulates food under two general criteria – adulteration and misbranding. The FDA was ineffective until 1938, at which time the passage of the Federal Food, Drug and Cosmetic Act of 1938 updated and tightened the definition of adulteration. This gave the agency the power to fine violators of the laws. After 20 years of application, interpretation, and enforcement of this Act, a significant revision took place in 1958. The Food Additives Amendment of 1958 led to a major change in the FDA’s approach to its activities. Congress applied the term ‘safe’ as the criterion for action, supplementing the term ‘adulteration.’ Over the years, with advances in science and  methods, the FDA has become more confident in its evaluation of food safety and US courts have given general endorsement to the agency’s decisions. In the fake food fight, the Agency has sought and won convictions against companies and individuals engaged in selling bogus fruit juices, honey, maple sugar, cream, olive oil, seafood, and many others. The FDA has major responsibilities for food supply in the USA, but other agencies also exert significant regulatory control over foods and beverages. The major agencies so far involved are the Department of Health and Human Services, the US Department of Agriculture Inspection Services, the US Department of Commerce, the Environmental Protection Agency and Centers for Disease Control and Prevention (CDC). The FDA relies heavily on industry and consumers to help identify instances of economic fraud. The detective work of FDA inspectors in the premises of suspect companies is also valuable. Cooperation with other foreign government bodies prevents adulterated foods banned in one country being shipped to another. Some adulterants recently reported in FDA files are: beet sugar or corn syrup in orange juice; canola oil in olive oil; sugar, water, hydrolyzed inulin syrup in apple juice; corn oil in dairy cream; corn syrup in maple and sorghum syrups or honey; water and sodium tripolyphosphate in scallops; potato starch in horseradish; salt and water in milk and sawdust in ginseng dietary supplement. The Safe Food Act of 1997, by which the food safety and inspection functions of 12 agencies have been consolidated into a single independent agency, is expected to combat even more effectively dishonest or fraudulent practices not only in a federal but also in an international context.

Toxicological Implications of Economic Adulteration of Food

In the past, the deliberate adulteration of food with untested chemicals or poisonous substances was widespread. In the 20th century, developments in the analytical field and improvement of legislation have brought many of these illegal and unethical practices under control, but cases of food adulteration with toxicological consequences have not completely disappeared. One serious case of malpractice in the food industry is the use of denatured rapeseed oil for edible purposes. This caused the outbreak referred to as Spanish toxic oil syndrome. In 1981, a disease broke out in Spain which rapidly took on epidemic proportions. The reported symptoms were respiratory distress, nausea, fever, vomiting, headaches, myalgias, abdominal pain, and skin eruptions. Approximately 20 000 people were affected and more than 400 deaths were recorded. For many years, scientists all over the world tried hard to find an explanation and identify the toxic compounds causing the illness. Today, toxicologists and chemists are convinced that the toxic oil syndrome should be attributed to aniline used for denaturation, but there are different opinions concerning the nature of the toxic compounds. Phenylalamine, originating from the glucosinolates present in rapeseed oil, was for many years believed to be the etiological agent in toxic oil syndrome. The course of events, however, in the two factories processing the aniline containing rapeseed oil and simulating studies conducted in the UK do not confirm this hypothesis. Another explanation may be the formation of N-phenyl-amino propane diol esters of fatty esters under conditions favoring dehydration. This suggests that deodorization sludges containing free fatty acids (and aniline) were catalytically treated with glycerol to obtain reconstruction of triacylglycerols. The problem will remain unresolved unless experts visit Seville again, study in more depth the conditions of the episode, and implement simulation processes that include esterification of fatty acids with glycerol in the presence of aniline.

Cases of Economic Adulteration of Food

Cases of adulteration frequently reported in the literature concern not only the basic foods (oils and fats, milk and dairy products, meat, fish, and cereals) but also fruit juices, alcoholic beverages and wine, honey, chocolate, coffee and spices, essential oils, and flavorings. Some cases of the last decades with serious economic and other implications are briefly discussed below.

Wines

Some Austrian, German, and Italian wines were found in 1985 to have been illegally supplemented with diethylene glycol (DEG), not a permitted food additive, to improve body and sweetness. Soon after the scandal, a 30% drop in demand for wines was observed in Austria. In 1987 some Japanese wines were also reported to contain the same adulterant.

Fruit Juices

One case which involved economic fraud and coverup efforts is the adulterated apple juice for babies scandal. For many years, Beech-nut Nutrition Corporation purchased and used concentrated apple juice which contained cheap ingredients such as corn syrup, invert sugar, malic acid, caramel, and imitation flavor. Although it was the director of research and development who discovered the use of these adulterants, he was forced to resign. The FDA took action and in 1988 the company was heavily fined. Citrus juices are frequently adulterated in many ways. The price of grapefruit juice is always lower than that of orange juice, so their admixture can be expected. Misbranding of fruit juices made from imported concentrates is a common problem in Florida.

Vanilla Extracts

The adulteration of vanilla extracts with inexpensive synthetic vanillin represents a loss of millions of dollars to the vanilla extract industry. To obtain equal strength of flavor, either 28 g of synthetic vanillin or 4.5 l of single-fold vanilla extract is required. The ratio of cost is approximately 1:120, and this significant difference is a strong stimulus for adulteration. Nonvanilla vanillin can be prepared from lignin, eugenol, or guaiacol. Synthetic products have a characteristic vanilla-like note but they are inferior in organoleptic properties because the quality of natural vanilla derives not only from the concentration of vanillin but also from the presence of other valuable volatile flavor compounds.

Olive Oil

Olive oil, a food staple in the warmer regions around the Mediterranean, is now becoming more popular throughout Europe, the USA, Japan, and Australia. Olive oil is often adulterated with seed oils and olive residue oil (olive pomace, olive kernel, or olive husk oil). Esterified oil, which is prepared by re-esterifying low-grade olive oil or olive oil soapstock recovered from alkali refining, has also been used to adulterate olive oil products. A survey in 1982 in the USA demonstrated that many olive oil products (imported or locally produced) contained undeclared olive husk oil, esterified oils, and seed oils. The European legislation for olive oil characteristics issued in 1991 (and amended many times since then) is an important tool against sophisticated frauds. The most recently reported cases of virgin olive oil frauds are those where lower-grade olive oil (desterolized or mildly deodorized), or other oils having a similar composition (hazelnut oil, high oleic-sunflower oil) have been used.

Fish, Meat and their Products

Meat and fish commercial products, being the main food protein sources for human consumption, are most frequently adulterated with other proteins of inferior-quality fish species or of nonmeat origin (e.g., undeclared soya protein in pork sausages). Authentication of species is important because all meats are not safe for consumers (e.g., meat from cows which had bovine spongiform encephalopathy (BSE)) or meats which should not be used (endangered or overexploited resources).
Identification is more complex, especially when the analysis has to be carried out on cooked products. Fish traded in fillets or as fish fingers is the most frequent case of economic adulteration. Surimi, which was used in the past as a substitute for crab sticks, is no longer a cheap raw material because of overexploitation. Characteristic incidences of substitution of cheaper materials for more expensive ones include the fraudulent replacement of salmon, trout, plaice or lemon sole, and caviar. DNA analysis seems to be the answer to speciation problems related to fish trade.

Milk and Dairy Products

The addition of water is still the most frequent case of milk adulteration. False labeling of the animal origin of milk, the use of reconstituted powdered milk, and the addition of partially hydrogenated vegetable oils are currently a matter of investigation for milk and dairy products. Roquefort in France, manchego in Spain, pecorino in Italy and feta in Greece are cheeses of large economic importance which are frequently adulterated or misbranded. The manufacture of these products is strictly regulated in these countries and within the EU. Consumption of products containing undeclared milk has been associated with certain food allergies.

Wheat and Other Cereals

The main cases of adulteration reported and addressed analytically are the admixture of wheat and barley cultivars, the fraud of durum wheat flour with common wheat (mainly in pasta products), and the misbranding of various commercial types (cargo, milled, broken.

Genetically Modified Food

The rapid pace of development of genetically modified organisms (GMOs), especially food plants, and the commercialization of novel foods derived from GMOs have caused intense debate and consumer concern. Although there is no evidence of actual or potential harm of GM food, nothing can be certain in a field of rapid scientific and technological progress. The present EU legislation (regulations 258/97/EC and 1139/98) recognizes that a genuine choice of non-GM foods should be available to the public and that food containing identifiable GM material should be properly labeled. Against this background numerous questions have emerged concerning analytical aspects, ranging from sampling procedures to robustness of methods.

See our article in Portuguese about aduleration of mortadella:  Mortadela e 'Mortandela'

By M Tsimidou and D Boskou (Aristotle University of Thessaloniki, Greece) in the book 'The Encyclopedia of Food Sciences and Nutrition' (10 v.) Editor-in-Chief Benjamin Caballero (Johns Hopkins University), Academic Press-Elsevier Science Ltd. U.S.A, 2003, First volume p.42-47. Adapted and illustrated to be posted by Leopoldo Costa.