Food Science and Technology
Food Science and Technology
FOOD SCIENCE AND TECHNOLOGY
Among the concerns of food science and technology are postharvest changes in substances that nourish human beings. Food science examines everything that can happen to food between harvest and consumption. Food technology is used to develop and manage the processes by which food is transformed from raw harvest to edible goods purchased by individual consumers. Almost all foods are modified before consumption. Only some fruits, nuts, vegetables, meats, milk, and eggs may be eaten raw. About three-quarters of all the calories consumed by humans worldwide are derived from rice, wheat, and corn (maize)—truly the staff of life in almost all societies—all of which must be processed to make their delivery of nutrients feasible.
Food science and technology draw on chemistry, microbiology, engineering, physiology, toxicology, nutrition, dietetics, economics, marketing, and law; therefore, food science and food technology are inherently interdisciplinary subjects rather than narrow disciplines. Because of the importance of food, this topic also raises a host of ethical issues, including professional responsibility, equity of availability, determination of levels of safety in regard to public health, risk to workers' rights, and informed consent among consumers.
Along with the making of shelter and clothing, the securing and preparing of food constitute one of the oldest technical activities, being coeval with the emergence of Homo sapiens. Because of its importance, from the beginning of human society food appears to have been associated with a number of ethical judgments in the form of rituals and taboos. Gender differences in regard to food procurement evolved for natural reasons: Males were the hunters, and females were the gatherers and subsequently the crop cultivators. Anthropologists also focus on cultural aspects such as food as a means of asserting identity or group membership; the reciprocal effects of class or caste systems on foodways; communal eating and food as a means of bonding and hospitality; ritual aspects of food, for example, at funerals and weddings; and food taboos and food eaten for religious reasons—these so-called ceremonial foods include bread, wine, and oil, the first manufactured foodstuffs.
Two major changes allowed human populations to shift from nomadic hunting and gathering, which they had engaged in for hundreds of thousands of years, to living in settled communities. The first was the domestication of animals, probably beginning with that of the Asiatic wolf as an aid in hunting, around 13,000 years ago after the end of the last ice age. More significant was the keeping of lactating animals such as goats and sheep to guarantee a regular supply of milk, meat, and nonfood products. By approximately 10,000 years ago sheep had been domesticated in the area that is now Iraq, as were goats. Pigs were domesticated a thousand years later, and it took another thousand years before the wild aurochs had been transformed into cattle in the Balkan area.
The second achievement was the recognition of the relationship between plants and their seeds. This allowed a previously nomadic clan to settle in an appropriate landscape. With the receding ice, fields of wild grain or grasses with edible seeds appeared, and eventually women began to plant seeds in cleared areas.
Those two achievements were the key elements in what has come to be known as the Agricultural or Neolithic Revolution, which occurred during the New Stone Age, a period that began 11,000 years ago in southern Asia and 9,000 years ago in the Tigris and Euphrates river valleys, from where the new techniques began to spread. The agricultural revolution provided more and better food, promoting improved human fertility and longevity, and therefore increased human population numbers.
Differentiating between life-sustaining and harmful foods is probably an instinctive human behavior. People are drawn to carbohydrate-rich foods, which are generally sweet, and usually are repelled by alkaloidal products, which contain bitter toxic chemicals. An important discovery was that heat, such as that provided in cooking by fire or hot water, can alter the characteristics of food. The transformation of food materials by heat to make them consistently and predictably edible, flavorful, and spoilage-resistant developed into a practice that preceded techniques for deliberately changing inorganic materials, as in the making of pottery from clay some 30,000 years ago and then the use of metallurgy about 6,000 years ago, both of which contributed to cookery.
According to Harold McGee (1990), chemistry began with the "food chemistry" of ancestral cooks. The molecules those cooks transformed and manipulated were food molecules. Each time contemporary people prepare food for eating, whether in a large food-processing plant or in a kitchen, they replicate the origins of an art practiced since the harnessing of fire 125,000 years ago.
It was not until the Enlightenment and well into the Industrial Revolution that food became a focus of scientific study. It was the modern period as well that witnessed the related developments in public health, medical nutrition, and mechanization in food processing, especially for mass production. The adaptation of mass production technologies to agricultural production and food processing radically transformed human-food relations. Those processes made it possible for smaller numbers of food workers to support larger numbers of food consumers, thus promoting urbanization on an unprecedented scale. That urbanization led to new technologies of preservation, transportation, and marketing; inspired scientific studies of nutrition (because in many instances the new technologies altered the balances in traditional diets); and raised ethical issues about the treatment of food processing workers as well as equity in access and distribution (which previously had been subject to the negotiations characteristic of traditional cultures).
Nevertheless, the basic objectives of assuring a satisfactory supply of food did not change. Those objectives only become more visible, controllable, and subject to management. Indeed, only new insights and improved techniques can assure a continuing stream of food products for the growing human population.
The Perennial Vital Objectives
All functioning modern societies attempt to provide people with foods that are readily available, abundant, affordable, appealing, appetizing, nutritious, and safe. Agriculture (including fisheries), along with food science and food technology, is essential in meeting those goals. Since prehistoric times the objectives related to feeding a clan or a larger community have been optimization of harvest yields, prevention of losses, achievement of edibility, and protection of food integrity factors such as flavor, texture, color, and nutrition.
The food system—the path from soil to mouth or from farm to fork—is a precarious one. Numerous technologies are involved in the modern effort to bring food to consumers. Much can go wrong, and much depends on climate and other natural forces. However, human ingenuity, a multitude of tools, and technological interventions are the critical factors in seizing life-sustaining products from nature. Then all foods must be protected during the transfer from their production habitats to their final destination. The notion of a carefree dependence on the abundance of nature is far removed from reality.
Each food product on the shelves of grocery stores can be traced through its passage from harvest (including slaughtering and fishing) to channels of transportation and then to storage, packaging, and distribution until it is purchased for preparation in a consumer's kitchen or an efficient mass-feeding facility. About half of all dollars spent on food consumption in the United States at the beginning of the twenty-first century was expended in eating away from home.
Other animals compete with humans for the products of nature. The biblical scourges of locusts are a familiar example, but it is mainly invisible competitors that take the most. Bacteria, molds, yeasts, and even viruses consistently make foods unavailable, inedible, or the cause of disease. Only a few microorganisms have been put to positive use, mainly in fermentation. Because eradication is impossible, pest control is a major activity and expenditure for farmers and food processors and even for the food service industry and some householders. This war against microscopic competitors is waged most effectively with chemical weapons and must be affordable and properly done.
Current agricultural pesticides are largely products of the 1950s. As with all technological interventions, it soon was realized that there was a side effect in that pesticide residues on and in foods could be harmful to human health and to the environment. A typical quandary is the war against food pests. This battle involves powerful weaponry to assure an abundance of crops and may do damage to people as a side effect.
In addition to rodent, insect, and microbiological losses numerous chemical changes occur in foods that have unpleasant results. Soured milk, bitter rice, rancid fatty food, and other unpalatable edibles are thrown away. Not even animals are fed with them because their owners suspect the presence of toxic substances. The losses to the "food system" and to society are obvious. Equally obvious is the fact that such losses, along with food deterioration overall, can be avoided to a large extent through the judicious application of food technologies. That constitutes the major preoccupation of modern food processors and handlers, the custodians who take possession of food after harvesting and deliver it to end users in the expected qualities and quantities.
Food losses and food waste are enormous, although no accurate data exist. Ironically, in places where food crops are usually scarce, often because of a lack of technological intervention but also as a result of natural disasters, personal wastage is rare. In the developed parts of the world, where technology assures an abundance of food, there is usually gross disregard for optimal personal food utilization. Examples include tray waste in institutional facilities and careless housekeeping practices.
Food protection spans the spectrum from seeds to the moment of consumption. The initial responsibility lies with food producers. Agricultural research began in the nineteenth century. It has always been devoted mainly to production studies that have culminated in the use of chemical, mechanical, computer, and more recently bioengineering technologies. Each technology has had opponents, has sparked heavy discussion, and has been improved as a result. One insight has become clear: Without science and appropriately applied technologies improvement of the human condition would be slow, difficult, and painful.
From cutting to gamma-irradiation, the subject of food processing involves dozens of operations. Only a few can be mentioned in this brief overview. At the heart of food technology are several processing operations that are used to modify foods primarily to preserve them for later consumption. Water removal is one way to preserve a food: Raisins last longer than grapes, cheese and sausages can be stored for long periods, fruits can be converted to fermented beverages, and grains can be made into beer. In all these cases, the original food disappears but the nutritive value is preserved.
Another method of preservation is the use of chemicals, such as acids, that are antagonistic to spoilage microorganisms. During the 1990s about 5,000 people died every year in the United States from bacterial food poisoning. The human toll from poisoned food was almost unbelievably high until the advent of food technology, along with hygienic measures and medical advances. Vinegar, yogurt, and pickled foods are examples of acid-preserved foods.
The pickling of vegetables has a long history, especially in China, and has relied primarily on the use of salt (sodium chloride). The history of salt, which is considered the first "food" of commerce, is interwoven with that of food preservation (Kurlansky 2002). A high sugar content also preserves food, as in the case of candied fruit and confectionery products. The inspiration must have come from honey, the original natural preserved food.
Modern food markets provide evidence that almost everything people eat is modified before consumption. The rationale of most processing is to protect a food until it is consumed, and an understanding of food chemistry and microbiology is essential in that endeavor.
The simplest way to defeat microorganisms is to remove the water that is vital to them. Most foods that are not dried properly spoil very quickly, but substances antagonistic to microorganisms can be added directly or indirectly, as in lactic and alcoholic fermentations. The result is not only protection but also better nutrient availability and palatability. Lactic acid fermentation utilizes the destructive and digestive ability of certain microorganisms for human advantage, as in the cases of fermented cabbage and yogurt. The production of vinegar, beer, and wine provides examples of acetic and alcoholic fermentation. Other preservatives are microbial inhibitors such as spices, herbs, and salts.
Inhibition of oxidation is achieved mainly by means of the addition of antioxidants. Foods that are rancid or have lost flavor or color are considered spoiled. The mechanism is driven largely by enzymes native to foods but also by oxygen in the air. Consequently, air exclusion is a preservative technique. The first efforts at producing and sealing sterilized food were not made until the late 1700s, and plastic wraps and packaging under nitrogen were not used until the mid-1900s.
Canning is the most noteworthy achievement in food technology. It was invented by Nicolas Appert, who in 1790 in Paris preserved heated foods in bottles. Twenty years later the food-canning industry was born when the first "tin" cans were produced in England. Only with the 1864 work of Louis Pasteur on bacteria and asepsis did it become possible to understand the principles behind this food preservation technology. It was not until 1928 that Charles Olin Ball worked out the mathematical formula that made the thermal processing of foods possible. All heat sterilizing procedures in food and pharmaceutical industries in the early twenty-first century rely on Ball's work.
Legal and Ethical Issues
In 1939 in the United States the Institute of Food Technologists (IFT) was created. Similar professional associations now exist in most major countries. This represented the beginning of the coordination of all research activities and industrial development work involving foods. By 1960 several university food science departments had emerged. In the early 2000s there are nearly fifty in North America, and the IFT, headquartered in Chicago, has almost 30,000 members. This professional association publishes a number of journals and organizes well-attended annual meetings and expositions. Its mission is to establish and promote standards of professional excellence at local as well as international levels. The IFT fosters communication, contributes to public policy, and helps individuals achieve career goals. Along with its counterparts in other countries, it embraces objectives such as combating hunger, enhancing the quality of foods, and stimulating progress in the food technology industries.
IFT lists six core values in its current strategic plan:
- Act with integrity
- Foster inventive and adaptive leadership
- Demonstrate responsible stewardship
- Focus on members
- Value diversity
- Chanmpion sound science in the interest of public well-being
IFT's counterpart in the UK, the Institute of Food Science and Technology, has a somewhat more explicit code relating to ethics. Its 10 professional conduct guidelines are entitled:
- Wholesomeness of food
- Relations with the media
- Confidentiality of information
- Conflicts involving professional ethics
- Duties towards subordinates
- Scientific issues and food promotion
- Responsibilities towards students
- Responsibilities towards the environment
- Members' business interests
- Responsibility to the profession
A number of activist groups have emerged with an interest in food technology. Greenpeace International is probably the best-funded and declares to "exist because this fragile earth deserves a voice, it needs solutions, it needs change. It needs action."
The Food Ethics Council was established in 1998 in England as a charitable trust. It has reported on such ethical issues ranging from drug use in farm animals to intellectual property in agriculture research.
It was inevitable that governments would take an interest in the food supply. Modern American food law began with the Food and Drug Act of 1906, also called the Pure Food Law. In 1938 it was redone as the Food, Drug, and Cosmetic Act, with amendments. The U.S. Food and Drug Administration (FDA) enforces this law through an elaborate set of regulations. Other agencies share this responsibility, including the U.S. Department of Agriculture, the Federal Trade Commission, and the Bureau of Alcohol, Tobacco, Firearms, and Explosives.
Food regulatory work often is subject to criticism. The public can get involved in the rulemaking process, but it is mainly consumer advocates along with trade associations and only occasionally individuals that participate.
At one time mainly unprocessed and raw foods were consumed, but then cookery, pasteurization, and sterilization created the category of mildly processed foods. Milling, brewing, refining, dairy processing, and many other food operations that frequently relied on the use of so-called food additives and blending with other ingredients provided what often is termed highly processed or reformulated foods.
The newest category in this area is synthetic food, which can be thought of as engineered edible systems. An imitation orange drink powder that could be reconstituted with water at home or during space flight was the first example, appearing in the 1970s. Except for the sugar in it there is no agricultural ingredient, and the sugar could be replaced with a synthetic sweetener to make it a diet beverage or a food for diabetic persons.
It can be said that a gradual merging of the food and pharmaceutical industries is under way. The word nutraceutical was coined in the 1990s, and with it came many foods and food components, including beneficial bacteria, that are claimed to have health-providing properties beyond those of traditional essential nutrients such as vitamins, amino acids, and certain minerals. Opportunities to defraud the public with scientifically unproven benefits are tempting; the subject of nutritional claims is debated hotly and is only in the early stages of governmental supervision.
Since biblical times human societies and their leaders have been interested in regulating trade and safeguarding foods. Food protection has economic and public health implications: People must be protected from cheaters and poisons. Because misrepresentation and adulteration can be inadvertent as well as deliberate, a legal and regulatory framework was needed to address these concepts and allow modern societies to function smoothly and safely.
The English Assize of Bread and Beer (assissa panis et cerevisiae) of 1266 attempted to control the quantity (weights and volumes) of food sold by merchants, not its quality. That law established strict penalties whose basic principles would be adopted by settlers in North America hundreds of years later. Adulteration was rampant, and the tools to detect it were lacking. In 1820 Frederick Accum, a German chemist and pharmacist living in London, published his Treatise on the Adulteration of Food and Culinary Poisons. Microscopy was an emerging technology that became the first analytical tool to verify food adulteration, mainly in the detection of rodent hairs and feces, insect fragments, and foreign objects such as dirt and unwanted plant matter. Chemical analysis has become a more powerful tool since that time, and the food laws of many nations stipulate the employment of food analysts and analytical methods. It is now possible to detect the presence of objectionable environmental chemical contaminants in trace amounts that are not significant in physiological terms, that is, amounts considered inconsequential.
Just as the law does not concern itself with trifles, the law of Paracelsus states that a small amount of a toxin is not worth considering because it has no effect. Parcelsus taught that "the dose makes the poison," and it can be demonstrated that a grain of salt has no effect on a living organism but that a cupful is deadly. Similarly, too much of a good thing may be harmful, as evidenced by the contemporary overconsumption of calories, especially in affluent societies. Sixty-five percent of Americans were considered obese at the start of the twenty-first century, and obesity is becoming the number one human health hazard. Discussion has begun about where to lay the blame for this phenomenon. Some have pointed to the "fast-food" industry as the primary culprit, ignoring free will, discipline, and responsibility.
The concept of American fast food also touches on ethical issues and may have spawned the "slow food" movement that arose in Italy in the late 1990s, presumably to resist the replacement of culinary traditions and the disappearance of local food varieties; however, it also might have been the product of anti-Americanism, anticapitalism, and antiglobalization. All over the world, especially in developing areas, the introduction of "Western food" constitutes a threat to indigenous food crops and processing operations that have been practiced by women for centuries. The enrichment of a local diet is welcome from a nutritional standpoint, but it also is believed to undermine the potential for self-sufficiency and the value of indigenous knowledge. Entomophagy is widely accepted and always has been: Some five hundred insect species serve as food sources worldwide. The subject of underutilized species has been dealt with by the many organizations, and as a result new foods have been "unearthed." The fungal protein quorn, manufactured in the United Kingdom and sold as a meat substitute, is an example. Other potentials are seen in leaf protein concentrate, processed plankton or cellulose, and recycled waste products.
The newest trend in the food field is genetic engineering. Apart from drug manufacturing it is applied mainly in production agriculture and involves recombinant DNA and cell fusion techniques. The driving force behind this food biotechnology is the creation of higher yields from plants and animals. Critics argue that the driving force here is not a humanitarian spirit but corporate greed. Related objectives of the new biotechnology are foods with improved nutritional properties, such as the Swiss-originated vitamin A-enriched rice that is claimed to combat childhood blindness in Asian areas and the production of crops with better utilization/processing potential, including better flavor. Many of these products are already on the market. However, there has been vigorous political and even religious debate over these genetically modified (GM) crops and foods, even over GM drugs such as insulin.
New enzymes derived from GM microorganisms are being used in food processing. Indeed, knowledge about genetic maps and the amino acid sequences of proteins makes it possible to tailor-make food ingredients with specific desirable functions and properties. Among the 150 microbial enzymes in use for food production more than 40 are produced from GM microorganisms. It is surprising to many people that practically every item on an American restaurant menu has been subject to genetic modification. Since the introduction of GM foods in the 1980s a quiet revolution in the food supply has been under way. Worldwide, 46 percent of soybean acreage and 7 percent of corn fields were sowed with transgenic crops in 2001. No transgenic animals are used in food, mainly because of ethical barriers.
Disagreement about the safety of GM foods is rooted in the differences between American and European regulatory principles: regulation of the nature of the product in the United States versus regulation of the manner in which a product is produced in Europe. One consequence of the debate was the refusal in 2002 by the Zambian government to receive food aid from the United States because it involved GM food.
All new technologies seem to be accompanied by early resistance. GM crops have been embraced in the developing parts of the world, as was discussed during the Twelfth World Congress of Food Science and Technology in 2003. Food scientists are bracing themselves as the era of GM foods is unfolding. One challenge is to develop analytical methods that will differentiate between a GM species and a conventional one. The current debate seems to indicate that consumers wish to have a choice in selecting one or the other, and regulators may be charged by policymakers to monitor the trade in and consumption of these foods.
Food technology has improved the lot of humankind, but the work is far from over. Better tools will be designed, and it will be necessary to engage in transfers of food technology and institute governance, education, and transportation infrastructures so that no needy individual is left behind.
Davidson, Alan. (1999). The Oxford Companion to Food. Oxford: Oxford University Press. Considered to be the opus magnum from one of the world's great authorities on the history and use of food. It has 2,560 A-Z entries on 892 pages including 40 feature articles on staple foods.
Encyclopaedia of Food Science, Technology and Nutrition. (1993). London: Academic Press. About 1,000 entries written by international experts. The eight volumes contain 5,364 pages; agricultural aspects are not covered.
Kass, Leon R. (1994). The Hungry Soul—Eating and the Perfecting of Our Nature. New York: Free Press. An exploration of the natural and cultural act of eating; how homo sapiens has humanized eating, even though it is an urgent and basic animal necessity.
Kurlansky, Mark. (2002). Salt—A World History. Toronto: Alfred A. Knopf Canada. The long and intriguing history of the "only rock we eat" is also a very important part of humankind.
McGee, Harold. (1990). The Curious Cook: More Kitchen Science and Lore. San Francisco: North Point Press. An investigation into culinary problems and dogma, telling in plain English what science has discovered about the food we eat.
Pyke, Magnus. (1970). Food Science and Technology, 3rd edition. London: John Murray. Throughout his career the author has drawn attention to the importance of food technology and nutrition via a dozen books and numerous radio broadcasts and public lectures.
Toussaint-Samat, Maguelonne. (1992). A History of Food, trans. Anthea Bell. Cambridge, MA: Blackwell. A comprehensive 801-page reference history of foodstuffs, the story of cuisine, and the social history of eating, from the origins of mankind to the modern-day technological era.
Trager, James. (1996). The Food Chronology. London: Aurum Press. A sweeping and entertaining 783-page overview of the cultural development of food and food availability throughout human history.
Wiley Encyclopedia of Food Science and Technology, 2nd edition. (2000). New York: Wiley. The four volumes contain articles by 368 contributors around the world with information useful to food engineers, chemists, biologists, ingredient suppliers, and other professionals.