This science is too new to guarantee that problems will not occur in the future. When moved from one species to another, genes can create new unknown dangers. Once released into the natural environment, genetically modified plants interbreed with those in the wild. The spread of modified genes from one organism to another in the wild is technically termed a gene flow. It has already led to the creation of new strains of superweeds that are resistant to herbicides. Perhaps most worrying of all, there is no way of recalling a genetic modification. Once released into the environment, genetic pollution cannot be cleaned up; it will survive so long as there is life on Earth. The environment will be irreversibly altered. Natural plants and animals could be driven out.
Mistakes have already been made in genetic engineering. Use of genetically modified bacteria in the food supplement Tryptophan may have caused 37 deaths in the USA since 1989 as well as permanently disabling thousands of people.
A company called Pioneer Hi-Bred developed a variety of genetically modified soya spliced with a brazil nut gene to increase its protein content. When it was discovered that individuals allergic to brazil nuts also reacted to the modified soya, the company had to withdraw the product.
CARBOHYDRATES
Among common carbohydrates are sugar and starch. Although these substances differ widely from one another in properties and constitution, they show a very definite point of resemblance. They are all composed of carbon, hydrogen and oxygen, and the hydrogen and oxygen are always in the same ratio to one another as in water, i.e., two of hydrogen to one of oxygen. The name, therefore, of carbohydrates was given because these compounds seemed to be built up of carbon and water in different proportions. Thus glucose, as sugar has a formula C6H1206 which might be represented as 6C + 6H20. It may be pointed out that this last method of representation is only referred to for the purpose of showing how the name arose. There is hardly a plant that does not contain either sugar or starch or cellulose or even all the three of them. The sugars and starches are among our most common foods, and the celluloses though not useful as a food, are found the main constituents of wood, paper, cotton and other fibres or fibrous materials.
Our ordinary everyday life leads us to think that there is only one sugar, viz. that we use as a sweetening agent for tea. In fact there are many sugars, they are glucose (so-called dextrose or grape-sugar), fructose (also called levulose) and galactose.
Glucose or grape-sugar is found in large quantities in grapes. When these are dried in the sun to form resins, the glucose in the juice separates out as hard brown nodules. It |is frequently found mixed with fructose in the juice of fruity, in the roots and leaves of plants and in honey. It can also be obtained from cane sugar and starch. Glucose is soluble in about its own weight of water and is not so sweet as ordinary cane sugar.
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It readily ferments with yeast and yield principally alcohol and carbon dioxide.
Fructose occurs with glucose in the juice of sweet fruits and in honey. It is more soluble in water than glucose, and is about as sweet as the latter. It ferments with yeast but not as rapidly as glucose.
VITAMINS
A vitamin is an organic compound required as a nutrient in tiny amounts by an organism. A compound is called a vitamin when it cannot be synthesized in sufficient quantities by an organism, and must be obtained from the diet. Thus, the term is conditional both on the circumstances and the particular organism.
Vitamins are classified by their biological and chemical activity, not their structure. Thus, each "vitamin" may refer to several vitamer compounds that all show the biological activity associated with a particular vitamin. Such a set of chemicals are grouped under an alphabetized vitamin "generic descriptor" title, such as "vitamin A," which includes the compounds retinal, retinol, and many carotenoids. Vitamers are often inter-convertible in the body. The term vitamin does not include other essential nutrients such as dietary minerals, essential fatty acids, or essential amino acids, nor does it encompass the large number of other nutrients that promote health but are otherwise required less often.
Vitamins have diverse biochemical functions, including function as hormones (e.g. vitamin D), antioxidants (e.g. vitamin E), and mediators of cell signaling and regulators of cell and tissue growth and differentiation (e.g. vitamin A). The largest number of vitamins (e.g. B complex vitamins) function as precursors for enzyme cofactor bio-molecules (coenzymes), that help act as catalysts and substrates in metabolism. When acting as part of a catalyst, vitamins are bound to enzymes and are called prosthetic groups. For example, biotin is part of enzymes involved in making fatty acids. Vitamins also act as coenzymes to carry chemical groups between enzymes. For example, folic acid carries various forms of carbon group methyl, formyl and methylene - in the cell. Although these roles in assisting enzyme reactions are vitamins' best-known function, the other vitamin functions are equally important.
Vitamins are essential for the normal growth and development of a multicellular organism. For the most part, vitamins are obtained with food, but a few are obtained by other means.
Once growth and development are completed, vitamins remain essential nutrients for the healthy maintenance of the cells, tissues, and organs that make up a multicellular organism; they also enable a multicellular life form to efficiently use chemical energy provided by food it eats, and to help process the proteins, carbohydrates, and fats required for respiration.
DRYING FOOD
Drying is a method of food preservation that works by removing water from the food, which prevents the growth of microorganisms and decay. Drying food using the sun and wind to prevent spoilage has been known since ancient times. Water is usually removed by evaporation (air drying, sun drying, smoking or wind drying) but, in the case of freeze-drying, food is first frozen and then water is removed by sublimation.
Bacteria and micro-organisms within the food and from the air need the water in the food to grow. Drying effectively prevents them from surviving in the food. It also creates a hard outer-layer, helping to stop micro-organisms from entering the food.
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Many different foods are prepared by dehydration. Good examples are meat such as prosciutto (Parma ham), bresaola, and beef jerky. Dried and salted reindeer meat is a traditional Sami food. First the meat is soaked / pickled in saltwater for a couple of days to guarantee the conservation of the meat. Then the meat is dried in the sun in spring when the air temperature is below zero. The dried meat can be further processed to make soup.
Fruits change character completely when dried: the plum becomes a prune, the grape a raisin; figs and dates are also transformed. Drying is rarely used for vegetables as it removes the vitamins within them, however bulbs, such as garlic and onion, are often dried. Also chilies YL are frequently dried. Edible and psilocybin mushrooms, as well as other fungi, are also sometimes dried for preservation purposes, to affect the potency of chemical components, or so they can be used as seasonings.
For centuries, much of the European diet depended on dried cod, known as salt cod or bacalhau (with salt) or stockfish (without). It formed the main protein source for the slaves on the West Indian plantations and was a major economic force within the triangular trade. Dried shark known as Hákarl is a delicacy in Iceland.
SUGARING
Sugaring is a food preservation method, similar to pickling. Sugaring is the process of desiccating a food by first dehydrating it, than packing it with pure sugar. This sugar can be crystalline in the form of table or raw sugar, or it can be a high sugar density liquid such as honey, syrup or molasses.
The purpose of sugaring is to create an environment hostile to microbial life and prevent food spoilage. Sugaring is commonly used to preserve fruits as well as vegetables such as ginger. From time to time sugaring has also been used for non-food preservations. For example, honey was used as part of the mummification process in some ancient Egyptian rites.
A risk in sugaring is that sugar itself attracts moisture. Once a sufficient moisture level is reached, native yeast in the environment will come out of dormancy and begin to ferment the sugars into alcohol and carbon dioxide. This leads to the process of fermentation. Although fermentation can be used as a food preservation method, it must be intentionally controlled, or the results will tend to be unpleasant.
The of sugaring is the most popular in maple syrup production.
Maple syrup production is centred in northeastern North America, and is commonly associated with Quebec in Canada; however, given the correct weather conditions, it can be made wherever maple trees grow such as Vermont in United States. Usually, the maple species used are the sugar maple (Acer saccharum) and the black maple (Acer nigrum), because of a high sugar content in the sap of roughly two percent. A maple syrup production farm is called a "sugar bush" or "the sugarwoods". Sap is often boiled in a "sugar house" (also known as a "sugar shack" or cabane à sucre), a building which is louvered at the top to vent the steam from the boiling sap.
FREEZE DRYING
Freeze-drying (also known as lyophilization or cryodesiccation) is a dehydration process typically used to preserve a perishable material or make the material more convenient for transport. Freeze-drying works by freezing the material and then reducing the surrounding pressure and adding enough heat to allow the frozen water in the material to sublime directly from the solid phase to gas.
If a freeze-dried substance is sealed to prevent the reabsorption of moisture, the substance may be stored at room temperature without refrigeration, and be protected against spoilage for many years. Preservation is possible because the greatly reduced water content inhibits the action of microorganisms and enzymes that would normally spoil or degrade the substance.
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Freeze-drying also causes less damage to the substance than other dehydration methods using higher temperatures. Freeze-drying does not usually cause shrinkage or toughening of the material being dried. In addition, flavors and smells generally remain unchanged, making the process popular for preserving food. However, water is not the only chemical capable of sublimation, and the loss of other volatile compounds such as acetic acid (vinegar) and alcohols can yield undesirable results.
Freeze-dried products can be rehydrated (reconstituted) much more quickly and easily because the process leaves microscopic pores. The pores are created by the ice crystals that sublimate, leaving gaps or pores in their place.
Freeze-drying is used to preserve food and make it very lightweight. The process has been popularized in the forms of freeze-dried ice cream, an example of astronaut food. It is also popular and convenient for hikers because the reduced weight allows them to carry more food and reconstitute it with available water. Instant coffee is sometimes freeze-dried, despite high costs of freeze-dryers. The coffee is often dried by vaporization in a hot air flow, or by projection on hot metallic plates. Freeze-dried fruit is used in some breakfast cereal. However, the freeze-drying process is used more commonly in the pharmaceutical industry.
HIGH PRESSURE FOOD PRESERVATION
High pressure food preservation refers to high pressure used for food preservation. "Pressed inside a vessel exerting 70,000 pounds per square inch or more, food can be processed so that it retains its fresh appearance, flavor, texture and nutrients while disabling harmful microorganisms and slowing spoilage.
High pressure food preservation was first discovered in the 1890s. In the 1990s, high pressure preserved acidified shelf stable food was demonstrated; but the processing equipment was too expensive for most commercial applications. By 2001, adequate commercial equipment was developed so that by 2005 the process was being used for products ranging from orange juice to meat and widely sold. Used since 1991 in Japan for jellies and jams, high pressure preserved food met its first commercial success in the U.S. market when Fresherized Foods in Keller, Texas, employed it for guacamole dip processing. Hormel Foods, Austin, Minn., and Perdue Farms, Salisbury, Md., are employing the process to sterilize lunchmeat, chicken strips, and other meat items and to extend shelf-life to 100 days or longer.
Using hydrostatic pressure, water is pumped into a sturdy closeable steel vessel. Foods of any shape or size are equally squeezed around its surface area without crushing the food particles. It's effective on most moist foods, such as fruits, vegetables, sauces and ready-to-eat meats. It can even shell whole uncooked lobster. The high pressure cycle takes no longer than six minutes, compared to traditional high-temperature processing that takes an hour or longer, without causing chemical changes that degrade food quality.
The 2002 Industrial Achievement Award recognized the process with honors for significant advancement in food science and technology for food production.
Frost & Sullivan's 2005 Technology Leadership Award in the field of emerging food-processing technologies recognized ultra-high pressure processing technologies that destroy food-borne pathogens and spoilage organisms, thereby ensuring product safety and enabling longer shelf life.
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A DIETARY SUPPLEMENT
A dietary supplement, also known as food supplement or nutritional supplement, is a preparation intended to provide nutrients, such as vitamins, minerals, fatty acids or amino acids that are missing or are not consumed in sufficient quantity in a person's diet. Some countries define dietary supplements as foods, while in others they are defined as drugs.
Supplements containing vitamins or dietary minerals are recognised by the Codex Alimentarius Commission, the United Nations' highest authority on food standards, as a category of food.
In the United States, a dietary supplement is defined under the Dietary Supplement Health and Education Act of 1994 as a product that is intended to supplement the diet and contains any of the following dietary ingredients: a vitamin, a mineral, an herb or other botanical (excluding tobacco), an amino acid.
A dietary substance is for use by people to supplement the diet by increasing the total dietary intake, or a concentrate, metabolite, constituent, extract, or combination of any of the above.
Dietary supplements are permitted to make structure/function claims. These are broad claims that the product can support the structure or function of the body (e.g., "glucosamine helps support healthy joints", "the hormone melatonin helps establish normal sleep patterns"). The FDA must be notified of these claims within 30 days of their first use, and there is a requirement that these claims be substantiated.
Other claims that required approval from FDA include health claims and qualified health claims. Health claims are permitted to be made if they meet the requirements for the claims found in the applicable regulations. Qualified health claims can be made through a petition process, including scientific information, if FDA has not approved a prior petition.
The claims that a dietary supplement makes are essential to its classification. If a dietary supplement claims to cure, mitigate, or treat a disease, it would be considered to be an unauthorized new drug and in violation of the applicable regulations and statutes.
In Europe, it is also an established view that food supplements should not be labeled with drug claims but can bear health claims, although to a degree that differs from one member state to the other.
The Food Supplements Directive requires that supplements be demonstrated to be safe, both in quantity and quality. Some vitamins are essential in small quantities but dangerous in large quantities, notably Vitamin A. Consequently, only those supplements that have been proven to be safe may be sold without prescription.
As a rule, BADSs are foodstuffs with clinically proven effectiveness. BADSs are recommended not only for prophylactics, but can be included into a complex therapy for the prevention of pharmaceutical therapy's side effects and for the achievement of complete remission.
The development of BADSs and their applications has been very fast moving. They were originally considered as dietary supplements for people who had heightened requirements for some normal dietary components (for example, sportsmen). Later, they were employed as preventive medicines against chronic diseases.
A COLORFUL HISTORY
Color additives have long been a part of human culture. Archaeologists date cosmetic colors as far back as 5000 B.C. Ancient Egyptian writings tell of drug colorants, and historians say food colors likely emerged around 1500 B.C.
Through the years, color additives typically came from substances found in nature, such as turmeric, paprika and saffron. But as the 20th century approached, new kinds of colors appeared that offered marketers wider coloring possibilities. These colors, many whipped up in the chemist's lab, also created a range of safety problems. In the late 1800s, some manufacturers colored products with potentially poisonous mineral- and metal-based compounds. Toxic chemicals tinted certain candies and pickles, while other color additives contained arsenic or similar poisons. Historical records show that injuries, even deaths, resulted from tainted colorants. Food producers also deceived customers by employing color additives to mask poor product quality or spoiled stock.
By the turn of the century, unmonitored color additives had spread through the marketplace in all sorts of popular foods, including ketchup, mustard, jellies, and wine. Sellers at the time offered more than 80 artificial coloring agents, some intended for dyeing textiles, not foods. Many color additives had never been tested for toxicity or other adverse effects.
As the 1900s began, the bulk of chemically synthesized colors were derived from aniline, a petroleum product that in pure form is toxic. Originally, these were dubbed "coal-tar" colors because the starting materials were obtained from bituminous coal. (These formulations still are used todayalbeit safelyfor most certifiable color additives.) Though colors from plant, animal and mineral sourcesat one time the only coloring agents available-remained in use early in this century, manufacturers had strong economic incentives to phase them out. Chemically synthesized colors simply were easier to produce, less expensive, and superior in coloring properties. Only tiny amounts were needed. They blended nicely and didn't impart unwanted flavors to foods. But as their use grew, so did safety concerns.
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In 1906, Congress passed the Pure Food and Drugs Act. This marked the first of several laws allowing the federal government to scrutinize and control additives use.
THE NEED FOR ARTIFICIAL SWEETENERS IN A SWEET-TOOTH SOCIETY
Ours is a sweet civilization. Sugar has the dual attraction of providing quick energy and of being sweet. It is not surprising that sugar consumption has increased dramatically in all societies that reach a certain stage of development. Sugars provide about 20% of the energy intake in the USA. But there are problems with sugar: over consumption is implicated in obesity and diabetes, so sweeteners with no energy content are obviously desirable in many foods.
There are several natural sugars. Common granulated sugar is sucrose, a combination of the two simpler sugars glucose and fructose. Lactose (milk sugar) consists of glucose and galactose, whilst maltose, produced by the malting of barley, is a combination of two molecules of glucose. The non-sugar sweeteners are many times sweeter than natural sugars and have no energy content whatsoever. These intense sweeteners are: acesulfame (150-200 times as sweet as sucrose: E950), aspartame (200 times as sweet as sucrose: E951), saccharin (300 times as sweet as sucrose: E954), cyclamates (30 times sweeter than sucrose:E952), thaumatin (E957) and neohesperidine dihydrochalcone (E959).
Non-sugar sweeteners are used in drinks, yogurt and other desserts, and baked products. These sweeteners have been extensively tested. Aspartame was tested for over a decade before being approved. It contains the natural amino acid phenylalanine and a very few people in the population have a hereditary disease in which they cannot metabolise phenylalanine. Products containing aspartame have to have a label warning against such use. It is important to stress that only people who cannot tolerate foods containing phenylalanine need to avoid aspartame.
There are some new sweeteners currently awaiting approval. Sucralose is 600 times sweeter than sucrose, is highly stable, and can be substituted for sugar in almost all its uses. Alitame is derived from the nutrient amino acids aspartic acid, alanine and an amide component. It is 2000 times sweeter than sucrose and, like sucralose, can be used in most products.
Bulk sweeteners are less concentrated and are similar in sweetening power to natural sugars: in fact they are derived from them by hydrogenation. Such sweeteners: maltitol (E965), xylitol (E967), and lactitol (E966), do not require insulin to metabolize them and can thus be used by diabetics, as can the intense sweeteners. High fructose corn syrup has become important in recent years, especially in cola drinks which now hardly ever contain sugar.
Studies have been made on the diet of young people and their intake of non-sugar sweeteners. Young people are the group most likely to consume more of the foods that contain these additives. The studies show that the acceptable daily intake is not exceeded even in this group.
FROM SHAMPOO TO CEREAL. SEEING TO THE SAFETY OF COLOR ADDITIVES
It starts when you get up in the morning.
You snatch a bar of soap and scrub your face. That's likely your first dab into the palette of added tints and hues that will color much of your day. Most of us hardly notice them, but color additives surround us. Juice, cereal, pastry, coffee creamer, vitamins-all are likely to have added colors.
Color additives make things attractive, appealing, appetizing. They also serve as a code of sorts, allowing us to identify products on sight, like medicine dosages and candy flavors. We might reason, for example, that a pale green candy is mint flavored, while a darker green one is lime. Based on our color analysis alone, there will probably be no surprises when we pop the candy into our mouths. With this rainbow hodgepodge bombarding us daily, it's only natural that consumers might wonder: Just how safe are all these colors? John E. Bailey, Ph.D., acting director of FDA's Office of Cosmetics and Colors explains that FDA has, over nearly a century, refined its process of monitoring and controlling color additive use. By law, industry must prove the safety of colors it sells. FDA ensures that colors on the market are safe for their intended purposes and do not cover up product inferiority or otherwise deceive consumers. FDA watches domestic color use closely, seizing products found unsafe.
Still, Bailey says, some consumers believe color additives can cause health problems or even be hazardous. This notion stems, he says, from persistent public attitudes about colors banned in the past. He says consumer confidence in the safety of all colors can be shaken when FDA removes a color from the market. But he emphasizes: "I think we can say with assurance that today's colors are safe if used properly and that consumers need not be worried."
Food for DIFFERENT AGE GROUPS
In comparison with their body weights, babies need large amounts of energy, protein and calcium since they are growing rapidly and forming bones and teeth. Breast milk is the ideal food for them, as it contains all the necessary nutrients in an easily assimilated form. Amounts of iron and copper are low in milk, but these minerals are provided by the stores built up in the liver before birth.
When babies are bottle-fed, the cows milk needs modifying as the proportion of nutrients is different from those in human milk. Cows' milk has more protein and calcium, but is lower in vitamins C and A. Bottle-fed babies are given extra vitamin C in the form of orange or hip juice. When the age of 4 months (or a weight of 6 kg) is reached the milk diet needs supplementing with broths which supply the iron necessary for blood formation. From 6 months of age, cereals and pureed fruits and vegetables can be introduced into the diet. These help to introduce new tastes and supply extra energy, vitamins and minerals. These supplements should contain little or no salt or sugar. An infant's kidneys cannot eliminate salts as an adult's can, and extra sugar may make babies overweight.
Young children have a high requirement for energy and protein, as they are very active and growing rapidly. Up to 5 years of age the R.D.A. for energy is about 100 kcal for each kilogram of body weight compared with 40 kcal per kilogram for an adult. This high need for energy gradually falls off until by
15-18 years of age they need much the same amount of energy as adults in proportion to their body weights.
At birth a baby needs three times as much protein per kilogram of body weight as an adult does. This need gradually falls, until at 8 years of age it is only twice the adult ratio.
For strong bones and teeth, and healthy blood, children need an adequate supply of minerals, particularly calcium, phosphorus and iron.
Eating habits are established in childhood, so the caterer who provides varied meals with the correct nutritional value is helping to establish a healthy approach to food in the future. This applies particularly to the energy content of the diet. The portions of food in 200 kcal is approximately one-tenth of the R.D.A. for energy for an 8-year-old. A glance at the figures reveals that the sugar provides only energy, while the equivalent portions of bread, oatmeal and cornflakes also contain significant amounts of protein, calcium, iron and B vitamins. Encouraging children to take more of their energy needs in the form of cereal foods rather than as between-meal sugary snacks will improve their nutrition as well as protecting their teeth against decay. Fresh fruits and vegetables are important in the diet for both young and old because they supply vitamin C (ascorbic acid). You will remember that this vitamin protects against infection, helps heal wounds and assists with the absorption of iron. But are all fruits and vegetables equally valuable as sources of vitamin C? Table 1 gives the ascorbic acid content of a selection of fruits and vegetables.
Table 1. Ascorbic acid content of some fruits and vegetables.
| Fruit | Ascorbic acid (mg/100g food) | Vegetable | Ascorbic acid (mg/100g food) |
| Oranges | 50 | Cauliflowers | 60 |
| Lemon | Runner beans | 20 | |
| Apples | 5 | Baked beans | |
| Pears | Carrots | ||
| Blackcurrants | 200 | Potatoes, boiled | |
| Grapefruit | Sprouts, raw | 90 | |
| Bananas | Sprouts, boiled |
The R.D.A. for ascorbic acid is 20 mg for young children and 30 mg for adolescents and adults. From the table we can see that:
1. Citrus fruits are rich sources of ascorbic acid, while some native fruits contain little vitamin C;
2. Vegetables such as cauliflower and sprouts are useful sources of the vitamin in winter, when fruit may be expensive and
3. Potatoes contain only a small amount of ascorbic acid even when new.`
However, we all eat large amounts of potatoes, so the total amount of the vitamin provided by this staple vegetable is by no means unimportant.
A good diet can prolong good health into old age. Many elderly people come into residential homes showing signs of nutritional deficiencies, and regain an interest in life when given a good diet.
In general their needs are similar to those of younger adults, except they need less energy. As with slimmers, it is important that proteins, minerals and vitamins are not cut down at the same time as the energy-giving foods. Meals need to be attractively flavoured because elderly people often have little sense of smell so food can seem unappetizing if it is not well seasoned.
