A Word on Ingredients
Those close to animal nutrition, whether retailers of pet foods, wholesalers, manufacturers or nutritional scientists in the business of formulating pet foods and additives know that serious consumers are concerned about the ingredients in the pet foods they buy and serve to their important canine and feline family members. Perhaps that concern is why so many rumors and bits of false information, suggestions and innuendo make their way from blogs and webpages, dog show conversations and a variety of articles into full blown theories about what ought to be in pet foods and what ought not to be there.
At Hi-Tek Rations, we are guided by a team of animal nutritionists, headed by company founder Leonard Powell, who has spent a lifetime formulating outstanding foods for animals, particularly the companion animals that are such an important part of all of our lives. The following listing of ingredients and the information about each and its role in outstanding nutritional health has been prepared to better explain the selection of each component formulated into Perfectly Natural Dog. We have chosen the ingredient panel from Perfectly Natural Dog – Adult Formula in descending order (largest quantity in terms of total ration is listed first with each subsequent ingredient following).
If you have questions that you believe require further discussion or if you have concerns not answered by the information on this website, we invite you to contact us via email by clicking on this link. Contact us.
Ingredients In Descending Order
Used in Perfectly Natural Dog (Adult Formula)
- Chicken Meal
- Brown Rice
- White Rice
- Chicken Fat (Preserved with Natural Mixed Tocopherols)
- White Fish
- Yeast Culture
- Fish Oil (Preserved with Natural Mixed Tocopherols)
- Flaxseed Meal
- Sea Salt
- Dried Kelp
- Potassium Chloride
- Dried Peas
- Dried Carrots
- Dried Cranberry
- Dried Tomato
- Natural Flavors
- Chicory Root
- Lactobacillus Acidophilus Fermentation Product
- Lactobacillus Casei Fermentation Product
- Bifido Bacterium Fermentation Product
- Enterococcus Faecium Fermentation Product
- Choline Chloride
- Yucca Schidigera Extract
- Vitamin E Supplement
- Niacin Supplement
- d-Calcium Pantothenate
- Vitamin A Acetate
- Riboflavin Supplement
- Vitamin B12 Supplement
- Thiamine Mononitrate
- Pyridoxine Hydrochloride
- Citric Acid
- Vitamin D3 Supplement
- Folic Acid
- Ferrous Sulfate
- Zinc Sulfate
- Zinc Proteinate
- Iron Proteinate
- Zinc Oxide
- Copper Sulfate
- Manganese Sulfate
- Manganese Proteinate
- Copper Proteinate
- Manganese Oxide
- Selenium Yeast
- Calcium Iodate
Chicken meal is the most efficient source of real chicken with only 4-6% water, unlike whole fresh chicken, which is 40% or more water. Not to be confused with by-products meal, chicken meal is real chicken meat, not feathers, beaks or other parts of the chicken.
Brown rice (or "hulled rice") is non-milled or partly milled rice, a kind of whole grain. Brown Rice is a natural grain that remains unbleached. It has a mild nutty flavor and is chewier than white rice. Today brown rice is a staple for health-conscious eaters who believe food should be consumed in its most natural state. Brown rice and white rice have similar amounts of calories, carbohydrates, and protein, although many types of brown rice contain more fat than white rice. The main differences between the two forms of rice lie in processing and nutritional content. When only the outermost layer of a grain of rice (the husk) is removed, brown rice is produced. To produce white rice, the next layers underneath the husk (the bran layer and the germ) are removed, leaving mostly the starchy endosperm. Several vitamins and dietary minerals are lost in this removal and the subsequent polishing process. A part of these missing nutrients, such as Vitamin B1, Vitamin B3, and iron are sometimes added back into the white rice making it "enriched", as food suppliers in the US are required to do by the Food and Drug Administration (FDA). One mineral not added back into white rice is magnesium; one cup (195 grams) of cooked long grain brown rice contains 84 mg of magnesium while one cup of white rice contains 19 mg. When the bran layer is removed to make white rice, the oil in the bran is also removed. Rice bran oil may help lower LDL cholesterol. Among other key sources of nutrition lost are small amounts of fatty acids and fiber. In addition to having greater nutritional value, brown rice is also said to be less constipating than white rice.
White rice is the name given to milled rice that has had its husk, bran, and germ removed. This is done largely to prevent spoilage and to extend the storage life of the grain. After milling, the rice is polished, resulting in a seed with a bright, white, shiny appearance.
The polishing process removes important nutrients. A diet based on unenriched white rice leaves people vulnerable to the neurological disease beriberi, due to a deficiency of thiamine (vitamin B1). White rice is often enriched with some of the nutrients stripped from it during its processing. Enrichment of white rice with B1, B3, and iron is required by law in the United States.
At various times, starting in the 19th century, brown rice and wild rice have been advocated as healthier alternatives. The bran in brown rice contains significant dietary fiber and the germ contains many vitamins and minerals. (See whole grain.)
As with all natural foods, the precise nutritional composition of rice varies slightly depending on the variety, soil conditions, environmental conditions and types of fertilizers.
Typically 100 g of uncooked rice produces around 240-260 g of cooked grains.
Barley is a cereal grain derived from the annual grass Hordeum vulgare.
Barley has many uses. It serves as a major animal fodder, as a base malt for beer and certain distilled beverages, and as a component of various health foods. It is used in soups and stews, and in barley bread of various cultures, from Scotland to Africa.
In a 2007 ranking of cereal crops in the world, barley was fourth both in terms of quantity produced (136 million tons) and in area of cultivation (566,000 km²). Barley contains eight essential amino acids. According to a recent study, eating whole grain barley can regulate blood sugar (i.e. reduce blood glucose response to a meal) for up to 10 hours after consumption compared to white or even whole-grain wheat, which has a similar glycemic index. The effect was attributed to colonic fermentation of indigestible carbohydrates. Barley can also be used as a coffee substitute.
Hulled barley (or covered barley) is eaten after removing the inedible, fibrous outer hull. Once removed, it is called dehulled barley (or pot barley or scotch barley). Considered a whole grain, dehulled barley still has its bran and germ making it a nutritious and popular health food. Pearl barley (or pearled barley) is dehulled barley which has been steam processed further to remove the bran. It may be polished, a process known as "pearling". Dehulled or pearl barley may be processed into a variety of barley products, including flour, flakes similar to oatmeal, and grits.
Barley-meal, a wholemeal barley flour that is lighter than wheatmeal but darker in color, is used in porridge and gruel in Scotland. Barley-meal gruel is known as Sawiq in the Arab world. With a long history of cultivation in the Middle East, barley is used in a wide range of traditional Assyrian, Arabic, Kurdish, Persian, and Assyrian foodstuffs including kashkak, kashk and murri. Barley soup is traditionally eaten during Ramadan in Saudi Arabia. It is also used in soups and stews in Eastern Europe. In Africa, where it is a traditional food plant, it has the potential to improve nutrition, boost food security, foster rural development and support sustainable landcare.
The six-row variety bere is cultivated in Orkney, Shetland, Caithness and the Western Isles in the Scottish Highlands and islands. The grain is used to make beremeal, used locally in bread, biscuits, and the traditional beremeal bannock.
Chicken fat is fat obtained (usually as a by-product) from chicken rendering and processing. Of animal-sourced substances, chicken fat is the highest in linoleic acid (over 23%). Tocopherols (or TCP) are a class of chemical compounds of which many have Vitamin E activity. It is a series of organic compounds consisting of various methylated phenols. Because the vitamin activity was first identified in 1936 from a dietary fertility factor in rats, it was given the name "tocopherol" from the Greek words “τοκος” [birth], and “φορειν”, [to bear or carry] meaning in sum "to carry a pregnancy," with the ending "-ol" signifying its status as a chemical alcohol. Tocotrienols, which are related compounds, may also have Vitamin E activity. All of these various derivatives with vitamin activity may correctly be referred to as "Vitamin E." Tocopherols and tocotrienols are fat-soluble antioxidants but also seem to have many other functions in the body.
Whitefish or white fish is a fisheries term referring to several species of demersal fish with fins, particularly cod (Gadus morhua), whiting (Merluccius bilinearis), and haddock (Melanogrammus aeglefinus), but also hake (Urophycis), pollock (Pollachius), or others. Whitefish (Coregonidae) is also the name of several species of Atlantic freshwater fish, so the use of the two-word term 'white fish' is less misleading.
White fish live on or near the seafloor, and can be contrasted with the oily or pelagic fish that live in the water column away from the seafloor. Unlike oily fish, white fish contain oils only in their liver, rather than in their gut, and can therefore be gutted as soon as they are caught, on board the ship. White fish has dry and white flesh.
White fish can be divided into benthopelagic fish (round fish which live near the sea bed, such as cod and coley) and benthic fish (which live on the sea bed, such as flatfish like plaice).
White fish is sometimes eaten straight but is often used reconstituted for fishsticks, gefilte fish, lutefisk, surimi (imitation crabmeat), etc. For centuries it was preserved by drying as stockfish and clipfish and traded as a world commodity. It is most widely known as the key ingredient in the classic British dish fish and chips. In Jewish cuisine, smoked whole whitefish and whitefish salad are delicacies enjoyed with bagels.
The potato is a starchy, tuberous crop from the perennial Solanum tuberosum of the Solanaceae family (also known as the nightshades). The word potato may refer to the plant itself as well as the edible tuber. In the region of the Andes, there are some other closely related cultivated potato species. Potatoes were first introduced outside the Andes region four centuries ago, and have become an integral part of much of the world's cuisine. It is the world's fourth-largest food crop, following rice, wheat, and maize. Long-term storage of potatoes requires specialized care in cold warehouses.
Wild potato species occur throughout the Americas, from the United States to Uruguay. The potato was originally believed to have been domesticated independently in multiple locations, but later genetic testing of the wide variety of cultivars and wild species proved a single origin for potatoes in the area of present-day southern Peru (from a species in the Solanum brevicaule complex), where they were domesticated 7,000-10,000 years ago. Following centuries of selective breeding, there are now over a thousand different types of potatoes. Of these subspecies, a variety that at one point grew in the Chiloé Archipelago (the potato's south-central Chilean sub-center of origin) left its germplasm on over 99% of the cultivated potatoes worldwide.
Yeasts are eukaryotic micro-organisms classified in the kingdom Fungi, with the 1,500 species currently described estimated to be only 1% of all yeast species. Most reproduce asexually by budding, although a few do so by binary fission. Yeasts are unicellular, although some species with yeast forms may become multicellular through the formation of a string of connected budding cells known as pseudohyphae, or false hyphae, as seen in most molds. Yeast size can vary greatly depending on the species, typically measuring 3-4 µm in diameter, although some yeasts can reach over 40 µm.
The yeast species Saccharomyces cerevisiae has been used in baking and in fermenting alcoholic beverages for thousands of years. It is also extremely important as a model organism in modern cell biology research, and is one of the most thoroughly researched eukaryotic microorganisms. Researchers have used it to gather information about the biology of the eukaryotic cell and ultimately human biology. Other species of yeast, such as Candida albicans, are opportunistic pathogens and can cause infections in humans. Yeasts have recently been used to generate electricity in microbial fuel cells, and produce ethanol for the biofuel industry.
Yeasts do not form a single taxonomic or phylogenetic grouping. The term "yeast" is often taken as a synonym for Saccharomyces cerevisiae, but the phylogenetic diversity of yeasts is shown by their placement in two separate phyla, the Ascomycota and the Basidiomycota. The budding yeasts ("true yeasts") are classified in the order Saccharomycetales.
The common oat (Avena sativa) is a species of cereal grain grown for its seed, which is known by the same name (usually in the plural, unlike other grains). While oats are suitable for human consumption as oatmeal and rolled oats, one of the most common uses is as livestock feed. Oats make up a large part of the diet of horses and are regularly fed to cattle as well. Oats are also used in some brands of dog and chicken feed.
Fish oil is oil derived from the tissues of oily fish. Fish oils contain the omega-3 fatty acids eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), precursors to eicosanoids that are known to reduce inflammation throughout the body, and are thought to have many health benefits.
Fish do not actually produce omega-3 fatty acids, but instead accumulate them from either consuming microalgae that produce these fatty acids, as is the case with fish like herring and sardines, or, as is the case with fatty predatory fish, by eating prey fish that have accumulated omega-3 fatty acids from microalgae. Such fatty predatory fish like shark, sword fish, tilefish, and albacore tuna may be high in omega-3 fatty acids, but due to their position at the top of the food chain, these species can accumulate toxic substances (see biomagnification). For this reason, the FDA recommends limiting consumption of certain (predatory) fish species (e.g. albacore tuna, shark, and swordfish) due to high levels of toxic contaminants such as mercury, dioxin, PCBs and chlordane. Fish oil is used as a component in aquaculture feed. More than 50 percent of the world's fish oil used in aquaculture feed is fed to farmed salmon.
Fish oil has been studied for treating clinical depression, anxiety, and enhancing the benefits from depression medications. Countries with the highest intake of fish in their diets are correlated with the lowest rates of depression among citizens.
Flaxseed is cold processed. Flaxseed meal is a convenient way of obtaining many of the nutritional benefits of flax seeds, including dietary fiber, lignans, magnesium, zinc and mucilage. Flaxseeds originated in the ancient Mid-East and were used in Biblical days as an important source of polyunsaturated fatty acids, including omega-3.
Chicken eggs are widely used in many types of dishes, both sweet and savory, including many baked goods. Eggs can be scrambled, fried, hard-boiled, soft-boiled, pickled, and refrigerated. They can also be eaten raw, though this is not recommended for people who may be especially susceptible to salmonella, such as the elderly, the infirm, or pregnant women. In addition, the protein in raw eggs is only 51% bio-available, whereas that of a cooked egg is nearer 91% bio-available, meaning the protein of cooked eggs is nearly twice as absorbable as the protein from raw eggs. As an ingredient, egg yolks are an important emulsifier in the kitchen, and the proteins in egg white allow it to form foams and aerated dishes.
The albumen, or egg white, contains protein but little or no fat, and can be used in cooking separately from the yolk. Ground eggshells are sometimes used as a food additive to deliver calcium. Every part of an egg is edible, although the eggshell is generally discarded.
Eggs add protein to a person's diet, as well as various other nutrients. Chicken eggs are the most commonly eaten eggs. They supply all essential amino acids for humans, and provide several vitamins and minerals, including vitamin A, riboflavin (vitamin B2), folic acid (vitamin B9), vitamin B6, vitamin B12, choline, iron, calcium, phosphorus and potassium. They are also a single-food source of protein.
All of the egg's vitamin A, D, and E are in the egg yolk. The egg is one of the few foods that naturally contain vitamin D. A large egg yolk contains approximately 60 Calories (250 kilojoules); the egg white contains about 15 Calories (60 kilojoules). A large yolk contains more than two-thirds of the recommended daily intake of 300 mg of cholesterol (although one study indicates that the body may not absorb much cholesterol from eggs). The yolk makes up about 33% of the liquid weight of the egg. It contains all of the fat, slightly less than half of the protein, and most of the other nutrients. It also contains all of the choline, and one yolk contains approximately half of the recommended daily intake. Choline is an important nutrient for development of the brain, and is said to be important for pregnant and nursing dogs to ensure healthy fetal brain development.
The diet of the laying hens can greatly affect the nutritional quality of the eggs. For instance, chicken eggs that are especially high in omega 3 fatty acids are produced by feeding laying hens a diet containing polyunsaturated fats and kelp meal. Pastured raised free-range hens which forage largely for their own food also tend to produce eggs with higher nutritional quality in having less cholesterol and fats while being several times higher in vitamins and omega 3 fatty acids than standard factory eggs. Focusing on the protein and crude fat content, a 2010 USDA study determined that there were no significant differences of these two macronutrients in consumer chicken eggs. Cooked eggs are easier to digest, as well as having a lower risk of salmonellosis.
Sea salt, obtained by the evaporation of seawater, is used in cooking and cosmetics. Historically called bay salt or solar salt, its mineral content gives it a different taste from table salt, which is pure sodium chloride, usually refined from mined rock salt (halite) or from sea salt. Generally more expensive than table salt, it is commonly used in gourmet cooking and specialty potato chips, particularly the kettle cooked variety (known as hand-cooked in the UK/Europe). Sodium and chloride are considered essential minerals in dog and cat diets.
Greg Aldrich, Ph.D. says, "Salt has traditionally been used as a preservative for fish, meat and some vegetables. Now, it is used every day as a seasoning on human foods. This free use of salt as a seasoning is a fairly recent application in people's diets and has probably caused the greatest misunderstanding of its use in pet food. The consumer must be making the leap in logic that the mere presence of salt on the ingredient panel means the pet's food is being flavored with excessive amounts of salt.
"The flaw in this theory is that most pet foods do not rely on salt as a seasoning. If you have ever tasted pet food, you know one thing for sure: It is bland. For our palate, it could do with a bit of salt seasoning. But in pet food salt is primarily used to a level necessary to meet nutrient requirements.
Both sodium and chloride are considered essential minerals in dog and cat diets. Deficiencies in sodium and chloride result in problems with nervous signal transmission, low blood pressure, restlessness, increased heart rate and pasty or thick mucus. The requirements (on a diet dry matter basis) range between 0.06-0.30% for sodium and 0.10-0.45% for chloride depending on species and life stage."
Dr. Greg Aldrich is president of Pet Food & Ingredient Technology Inc., which facilitates innovations in foods and ingredients for companion animals.
Kelps are large seaweeds (algae) belonging to the brown algae (Phaeophyceae) in the order Laminariales. There are about 30 different genera.
Kelps grow in underwater "forests" (kelp forests) in shallow oceans. The organisms require nutrient-rich water with temperatures below about 20 °C (68 °F). They are known for their high growth rate - the genera Macrocystis and Nereocystis can grow as fast as half a meter a day, ultimately reaching 30 to 80 m.
Through the 19th century, the word "kelp" was closely associated with seaweeds that could be burned to obtain soda ash (primarily sodium carbonate). The seaweeds used included species from both the orders Laminariales and Fucales. The word "kelp" was also used directly to refer to these processed ashes.
Bongo kelp ash is rich in iodine and alkali. In great amount, kelp ash can be used in soap and glass production. Until the Leblanc process was commercialized in the early 19th century, burning of kelp in Scotland was one of the principal industrial sources of soda ash (predominantly sodium carbonate). Alginate, a kelp-derived carbohydrate, is used to thicken products such as ice cream, jelly, salad dressing, and toothpaste, as well as an ingredient in exotic dog food and in manufactured goods. Giant kelp can be harvested fairly easily because of its surface canopy and growth habit of staying in deeper water. Kelp is also used frequently in seaweed fertilizer, especially in the Channel Islands, where it is known as vraic.
Kombu (Saccharina japonica and others), several Pacific species of kelp, is a very important ingredient in Japanese cuisine. Kombu is used to flavor broths and stews (especially dashi), as a savory garnish (tororo konbu) for rice and other dishes, as a vegetable, and a primary ingredient in popular snacks (such as tsukudani). Transparent sheets of kelp (oboro konbu) are used as an edible decorative wrapping for rice and other foods.
Kombu can be used to soften beans during cooking, and to help convert indigestible sugars and thus reduce flatulence. Because of its high concentration of iodine, brown kelp (Laminaria) has been used to treat goiter, an enlargement of the thyroid gland caused by a lack of iodine, since medieval times.
In 2010 a group of researchers in the University of Newcastle found that a fibrous material called algenate in sea kelp was better at preventing fat absorption than most over-the-counter slimming treatments in laboratory trials. As a food additive it may be used to reduce fat absorption and thus obesity.
Medically potassium chloride is used in the treatment of hypokalemia and associated conditions, for digitalis poisoning, and as an electrolyte replenisher. Potassium chloride has a crystalline structure like many other salts. Its structure is face-centered cubic. Its lattice constant is roughly 630 picometers. In chemistry and physics it is very commonly used as a standard, for example as a calibration standard solution in measuring electrical conductivity of (ionic) solutions, since carefully prepared KCl solutions have well-reproducible and well-repeatable measurable properties.
A pea is most commonly the small spherical seed or the seedpod of the legume Pisum sativum. Each pod contains several peas. Peapods are botanically a fruit, since they contain seeds developed from the ovary of a (pea) flower. However, peas are considered to be a vegetable in cooking. The name is also used to describe other edible seeds from the Fabaceae such as the pigeon pea (Cajanus cajan), the cowpea (Vigna unguiculata), and the seeds from several species of Lathyrus.
P. sativum is an annual plant, with a life cycle of one year. It is a cool season crop grown in many parts of the world; planting can take place from winter through to early summer depending on location. The average pea weighs between 0.1 and 0.36 grams. The species is used as a vegetable, fresh, frozen or canned, and is also grown to produce dry peas like the split pea. These varieties are typically called field peas.
The wild pea is restricted to the Mediterranean basin and the Near East. The earliest archaeological finds of peas come from Neolithic Syria, Turkey and Jordan. In Egypt, early finds date from ca. 4800-4400 BC in the Nile delta area, and from ca. 3800-3600 BC in Upper Egypt. The pea was also present in Georgia in the 5th millennium BC. Farther east, the finds are younger. Peas were present in Afghanistan ca. 2000 BC, in Harappa, Pakistan, and in northwest India in 2250-1750 BC. In the second half of the 2nd millennium BC this pulse crop appears in the Gangetic basin and southern India.
In early times, peas were grown mostly for their dry seeds. In modern times, however, peas are usually boiled or steamed, which breaks down the cell walls and makes the taste sweeter and the nutrients more bio-available. Along with broad beans and lentils, these formed an important part of the diet of most people in the Middle East, North Africa and Europe during the Middle Ages. By the 17th and 18th centuries it had become popular to eat peas "green", that is, while they are immature and right after they are picked. This was especially true in France and England, where the eating of green peas was said to be "both a fashion and a madness". New cultivars of peas were developed by the English during this time that became known as garden peas and English peas. The popularity of green peas spread to North America. Thomas Jefferson grew more than 30 cultivars of peas on his estate. With the invention of canning and freezing of foods, green peas became available year-round, and not just in the spring as before.
Fresh peas are often eaten boiled and flavored with butter and/or spearmint as a side dish vegetable. Salt and pepper are also commonly added to peas when served. Fresh peas are also used in pot pies, salads and casseroles. Pod peas (particularly sweet cultivars called mange tout and sugar peas, or the flatter "snow peas," called hé lán dòu, 荷兰豆 in Chinese) are used in stir-fried are used in stir-fried dishes, particularly those in American Chinese cuisine. Pea pods do not keep well once picked, and if not used quickly are best preserved by drying, canning or freezing within a few hours of harvest.
In India, fresh peas are used in various dishes such as aloo matar (curried potatoes with peas) or matar paneer (paneer cheese with peas), though they can be substituted with frozen peas as well. Peas are also eaten raw, as they are sweet when fresh off the bush. Split peas are also used to make dhal, particularly in Guyana, and Trinidad, where there is a significant population of Indians.
Dried peas are often made into a soup or simply eaten on their own. In Japan, China, Taiwan and some Southeast Asian countries, including Thailand and Malaysia, peas are roasted and salted, and eaten as snacks. In the UK, dried yellow split peas are used to make pease pudding (or "pease porridge"), a traditional dish. In North America, a similarly traditional dish is split pea soup.
Pea soup is eaten in many other parts of the world, including northern Europe, parts of middle Europe, Russia, Iran, Iraq and India. In Sweden it is called ärtsoppa, and is eaten as a traditional Swedish food that predates the Viking era. This food was made from a fast-growing pea that would mature in a short growing season. Ärtsoppa was especially popular among the many poor who traditionally only had one pot and everything was cooked together for a dinner using a tripod to hold the pot over the fire.
In Chinese cuisine, pea sprouts (豆苗 dòu miáo) are commonly used in stir-fries. Pea leaves are often considered a delicacy as well.
In Greece, Turkey, Cyprus, and other parts of the Mediterranean, peas are made into a stew with meat and potatoes.
In the United Kingdom, dried, rehydrated and mashed marrowfat peas, known by the public as mushy peas, are popular, originally in the north of England but now ubiquitously, and especially as an accompaniment to fish and chips or meat pies, particularly in fish and chip shops. Sodium bicarbonate is sometimes added to soften the peas. In 2005, a poll of 2,000 people revealed the pea to be Britain's 7th favorite culinary vegetable.
Processed peas are mature peas that have been dried, soaked and then heat treated (processed) to prevent spoilage-in the same manner as pasteurizing. Cooked peas are sometimes sold dried and coated with wasabi, salt, or other spices.
The carrot (Daucus carota subsp. sativus, Etymology: Middle French carotte, from Late Latin carota, from Greek karoton, originally from the Indoeuropean root ker- (horn), due to its horn-like shape) is a root vegetable, usually orange, purple, red, white, or yellow in color, with a crisp texture when fresh. The edible part of a carrot is a taproot. It is a domesticated form of the wild carrot Daucus carota, native to Europe and southwestern Asia. It has been bred for its greatly enlarged and more palatable, less woody-textured edible taproot, but is still the same species.
It is a biennial plant which grows a rosette of leaves in the spring and summer, while building up the stout taproot, which stores large amounts of sugars for the plant to flower in the second year. The flowering stem grows to about 1 meter (3 ft) tall, with an umbel of white flowers that produce a fruit called a mericarp by botanists, which is a type of schizocarp. The carrot gets its characteristic and bright orange color from ß-carotene, which is metabolized into Vitamin A in humans when bile salts are present in the intestines. Massive overconsumption of carrots can cause hypercarotenemia, a condition in which the skin turns orange (although hypercarotenemia is not itself dangerous unlike overdose of Vitamin A, which can cause liver damage). Carrots are also rich in dietary fiber, antioxidants, and minerals.
Cranberries are a group of evergreen dwarf shrubs or trailing vines in the genus Vaccinium subgenus Oxycoccos, or in some treatments, in the distinct genus Oxycoccos. They are found in acidic bogs throughout the cooler parts of the Northern Hemisphere. Cranberries are low, creeping shrubs or vines up to 2 m long and 5 to 20 cm in height; they have slender, wiry stems that are not thickly woody and have small evergreen leaves. The flowers are dark pink, with very distinct reflexed petals, leaving the style and stamens fully exposed and pointing forward. They are pollinated by domestic honeybees. The fruit is an epigynous berry that is larger than the leaves of the plant; it is initially white, but turns a deep red when fully ripe. It is edible, with an acidic taste that can overwhelm its sweetness.
Cranberries are a major commercial crop in certain American states and Canadian provinces (see "Cultivation and Uses" below). Most cranberries are processed into products such as juice, sauce, and sweetened dried cranberries (e.g. Craisins), with the remainder sold fresh to consumers. Cranberry sauce is regarded an indispensable part of traditional American and Canadian Thanksgiving menus and European winter festivals.
Since the early 21st century within the global functional food industry, there has been a rapidly growing recognition of cranberries for their consumer product popularity, nutrient content and antioxidant qualities, giving them commercial status as a "superfruit". Cranberries have moderate levels of Vitamin C, dietary fiber and the essential dietary mineral, manganese, as well as a balanced profile of other essential micronutrients. By measure of the Oxygen Radical Absorbance Capacity with an ORAC score of 9,584 units per 100 g, cranberry ranks near the top of 277 commonly consumed foods in the United States.
The tomato (Solanum lycopersicum, syn. Lycopersicon lycopersicum & Lycopersicon esculentum) is an herbaceous, usually sprawling plant in the Solanaceae or nightshade family, as are its close cousins potatoes, chili peppers, tobacco, eggplant and the poisonous belladonna. It is a perennial, often grown outdoors in temperate climates as an annual. Typically reaching to 1-3 meters (3-10 ft) in height, it has a weak, woody stem that often vines over other plants. The leaves are 10-25 centimeters (4-10 in) long, odd pinnate, with 5-9 leaflets on petioles, each leaflet up to 8 centimeters (3 in) long, with a serrated margin; both the stem and leaves are densely glandular-hairy. The flowers are 1-2 centimeters (0.4-0.8 in) across, yellow, with five pointed lobes on the corolla; they are borne in a cyme of 3-12 together. The tomato is native to South America. Genetic evidence shows that the progenitors of tomatoes were herbaceous green plants with small green fruit with a center of diversity in the highlands of Peru. These early Solanums diversified into the dozen or so species of tomato recognized today. One species, Solanum lycopersicum, was transported to Mexico where it was grown and consumed by prehistoric humans. The exact date of domestication is not known. Evidence supports the theory the first domesticated tomato was a little yellow fruit, ancestor of L. cerasiforme, grown by the Aztecs of Central Mexico who called it `xitomatl´, meaning plump thing with a navel, and later called tomatl by other Mesoamerican peoples. Aztec writings mention tomatoes were prepared with peppers, corn and salt, likely to be the original salsa recipe. Tomatoes are now eaten freely throughout the world, and their consumption is believed to benefit the heart among other things. They contain lycopene, one of the most powerful natural antioxidants, which, especially when tomatoes are cooked, has been found to help prevent prostate cancer. However, other research contradicts this claim. Lycopene has also been shown to improve the skin's ability to protect against harmful UV rays. Natural genetic variation in tomatoes and their wild relatives has given a genetic treasure trove of genes that produce lycopene, carotene, anthocyanin, and other antioxidants. Tomato varieties are available with double the normal Vitamin C (Doublerich), 40 times normal Vitamin A (97L97), high levels of anthocyanin (P20 Blue), and two to four times the normal amount of lycopene (numerous available cultivars with the high crimson gene).
The term natural flavor or natural flavoring means the essential oil, oleoresin, essence or extractive, protein hydrolysate, distillate, or any product of roasting, heating or enzymolysis, which contains the flavoring constituents derived from a spice, fruit or fruit juice, vegetable or vegetable juice, edible yeast, herb, bark, bud, root, leaf or similar plant material, meat, seafood, poultry, eggs, dairy products, or fermentation products thereof, whose significant function in food is flavoring rather than nutritional.
Common chicory, Cichorium intybus, is a bushy perennial herbaceous plant with blue, lavender, or occasionally white flowers. Various varieties are cultivated for salad leaves, chicons (blanched buds), or for roots (var. sativum), which are baked, ground, and used as a coffee substitute and additive. It is also grown as a forage crop for livestock. It lives as a wild plant on roadsides in its native Europe, and in North America and Australia, where it has become naturalized.
Root chicory (Cichorium intybus var. sativum) has been in cultivation in Europe as a coffee substitute. The roots are baked, ground, and used as a coffee substitute and additive, especially in the Mediterranean region (where the plant is native), although its use as a coffee additive is also very popular in India, parts of Southeast Asia, South Africa and southern United States, particularly in New Orleans. It has also been popular as a coffee substitute in poorer economic areas, and has gained wider popularity during economic crises such as the Great Depression in the 1930s. Chicory, with sugar beet and rye was used as an ingredient of the East German Mischkaffee (mixed coffee), introduced during the "coffee crisis" of 1976-79.
Some beer brewers use roasted chicory to add flavor to their stouts.
Around 1970 it was found that the root contains up to 20% inulin, a polysaccharide similar to starch. Inulin is mainly found in the plant family Asteraceae as a storage carbohydrate (for example Jerusalem artichoke, dahlia etc.). It is used as a sweetener in the food industry with a sweetening power 1/10 that of sucrose and is sometimes added to yogurts as a prebiotic. Inulin can be converted to fructose and glucose through hydrolysis. Inulin is also gaining popularity as a source of soluble dietary fiber.
Chicory root extract is a dietary supplement or food additive produced by mixing dried, ground, chicory root with water, and removing the insoluble fraction by filtration and centrifugation. Other methods may be used to remove pigments and sugars. Fresh chicory root typically contains, by dry weight, 68% inulin, 14% sucrose, 5% cellulose, 6% protein, 4% ash, and 3% other compounds. Dried chicory root extract contains, by weight, approximately 98% inulin and 2% other compounds. Fresh chicory root may contain between 13 and 23% inulin, by total weight.
Lactobacillus acidophilus (meaning acid-loving milk-bacterium) is a species in the genus Lactobacillus. L. acidophilus is a homo-fermentative species, fermenting sugars into lactic acid, which grows readily at rather low pH values (below pH 5.0) and has an optimum growth temperature of 30 °C (86 °F). L. acidophilus occurs naturally in the human and animal gastrointestinal tract, mouth, and vagina. Some strains of L. acidophilus may be considered to have probiotic characteristics. These strains are commercially used in many dairy products, sometimes together with S. salivarius ssp. thermophilus and Lactobacillus delbrueckii ssp. bulgaricus in the production of acidophilus-type yogurt.
L. acidophilus is part of the normal vaginal flora. The acid produced by L. acidophilus in the vagina may help to control the growth of the fungus Candida albicans, thus helping to prevent vaginal yeast infections. The same beneficial effect has been observed in cases of oral or gastrointestinal Candidiasis infections. Certain spermicides and contraceptive creams can kill L. acidophilus in the vagina, clearing the path to possible yeast infections.
Some strains of L. acidophilus have been studied extensively for health effects. A blend of probiotic strains containing L. acidophilus decreased the incidence of pediatric diarrhea. L. acidophilus led to a significant decrease in levels of toxic amines in the blood of dialysis patients with small bowel bacterial overgrowth. At adequate daily feeding levels, L. acidophilus may facilitate lactose digestion in lactose-intolerant subjects.
There are many types of fermented dairy products that use L. acidophilus. The most familiar to Americans are sweet acidophilus milk and yogurt. Sweet acidophilus milk is consumed by individuals who suffer from lactose maldigestion and intolerance, which occurs when enzymes (lactase) cannot break down lactose (milk sugar) in the intestine. Failure to digest lactose results in discomfort, cramps and diarrhea. A University of Nebraska study found that feed supplemented with L. acidophilus and fed to cattle resulted in a 61% reduction of Escherichia coli 0157:H7. Research has indicated L. acidophilus may be helpful reducing serum cholesterol levels.
Inulins are a group of naturally occurring polysaccharides produced by many types of plants. They belong to a class of fibers known as fructans. Inulin is used by some plants as a means of storing energy and is typically found in roots or rhizomes. Most plants that synthesize and store inulin do not store other materials such as starch. Inulin is increasingly used in processed foods because it has unusually adaptable characteristics. Its flavor ranges from bland to subtly sweet (approx. 10% sweetness of sugar/sucrose). It can be used to replace sugar, fat, and flour. This is particularly advantageous because inulin contains a quarter to a third of the food energy of sugar or other carbohydrates and a ninth to a sixth of the food energy of fat. While inulin is a versatile ingredient, it also has health benefits. Inulin increases calcium absorption and possibly magnesium absorption, while promoting the growth of intestinal bacteria. In terms of nutrition, it is considered a form of soluble fiber and is sometimes categorized as a prebiotic. Due to the body's limited ability to process polysaccharides, inulin has minimal increasing impact on blood sugar, and-unlike fructose-is not insulemic and does not raise triglycerides, making it considered suitable for diabetics and potentially helpful in managing blood sugar-related illnesses. The consumption of large quantities (in particular, by sensitive or unaccustomed individuals) can lead to gas and bloating, and products that contain inulin will sometimes include a warning to add it gradually to one's diet.
Lactobacillus casei is a species of genus Lactobacillus found in the human intestine and mouth. As a lactic acid producer, it has been found to assist in the propagation of desirable bacteria. This particular species of lactobacillus is documented to have a wide pH and temperature range, and complements the growth of L. acidophilus, a producer of the enzyme amylase (a carbohydrate-digesting enzyme). It is known to improve digestion and reduce lactose intolerance and constipation.
The most common application of L. casei is industrial, specifically for dairy production. However, a team of scientists from Simón Bolívar University in Caracas, Venezuela found that, by using Lactobacillus casei bacteria in the natural fermentation of beans, the beans contained lower amounts of the compounds causing flatulence upon digestion.
Lactobacillus casei is typically the dominant species of non-starter lactic acid bacteria (NSLAB) present in ripening Cheddar cheese, and, recently, the complete genome sequence of L. casei ATCC 334 has become available. L. casei is also the dominant species in naturally fermented Sicilian green olives.
A commercial beverage containing L. casei strain Shirota has been shown to inhibit the growth of H. pylori in a test tube. But, when the same beverage was consumed by humans in a small trial, H. pylori colonization decreased only slightly, and the trend was not statistically significant. Some L. casei are considered as probiotic and may be effective in alleviation of gastrointestinal pathogenic bacterial diseases. According to World Health Organization, those properties have to be demonstrated on each specific strain-including human clinical studies-to be valid.
Among the best-documented, probiotics L.casei, L. casei DN-114001, and L. casei Shirota have been extensively studied and are widely available as functional foods (see Actimel, Yakult).
In the past few years, there have been many studies in the decolorization of azo dyes by lactic acid bacteria such as L. casei TISTR 1500, L. paracasei, Oenococcus oeni. With the azoreductase activity, mono-, di- azo bonds are degraded completely, and generate other aromatic compounds as intermediates.
Bifidobacterium is a genus of Gram-positive, non-motile, often branched anaerobic bacteria inhabiting the gastrointestinal tract and vagina. Bifidobacteria are one of the major genera of bacteria that make up the gut flora, the bacteria that reside in the colon. Bifidobacteria aid in digestion, are associated with a lower incidence of allergies  and also prevent some forms of tumor growth. Some bifidobacteria are used as probiotics.
Before the 1960s, Bifidobacterium species were collectively referred to as "Lactobacillus bifidus". Bifidobacteria are considered as important probiotics and used in the food industry to relieve and treat many intestinal disorders. Bifidobacteria exert a range of beneficial health effects, including the regulation of intestinal microbial homeostasis, the inhibition of pathogens and harmful bacteria that colonize and/or infect the gut mucosa, the modulation of local and systemic immune responses, the repression of procarcinogenic enzymatic activities within the microbiota, the production of vitamins, and the bioconversion of a number of dietary compounds into bioactive molecules.
Bifidobacterium spp. are known to discourage the growth of Gram-negative pathogens in infants. Mother's milk contains lower quantities of phosphate (pH Buffer). Therefore, when mother's milk is fermented by Bifidobacterium spp. in the infant's GI tract, the pH is lower making it more difficult for Gram-negative bacteria to grow.
Enterococcus faecium is a gram-positive bacterium group D, alpha hemolitic or nonhemolitic in the genus Enterococcus. It can be a commensal (non-harmful coexisting organism), in the human intestine, but it may also be a pathogen -- causing diseases like neonatal meningitis.
Antibiotic-resistant E. faecium is often referred to as VRE (vancomycin-resistant enterococcus).
It is used as a probiotic in animals.
Choline chloride is an organic compound and a quaternary ammonium salt. It has a choline cation with chloride anion. An alternative name is hepacholine. Choline chloride is mass-produced and is an important additive in feed especially for chicken where it accelerates growth. With urea it forms a deep eutect biocolina and lipotril.
The Mojave yucca (Yucca schidigera), also known as the Spanish Dagger, is a flowering plant in the family Agavaceae. It is native to the Mojave Desert and Sonoran Desert of southeastern California, Baja California, southern Nevada and western Arizona.
The Mojave yucca is a small evergreen tree growing to 5 m tall, with a dense crown of spirally arranged bayonet-like leaves on top of a conspicuous basal trunk. The bark is gray-brown, being covered with brown dead leaves near the top, becoming irregularly rough and scaly-to-ridged closer to the ground. The leaves are 30-150 cm long and 4-11 cm broad at the base, concavo-convex, thick, very rigid, and yellow-green to blue-green in color.
The flowers are white, sometimes having a purple tinge, bell-shaped, 3-5 cm long (rarely to 7.5 cm), produced in a compact, bulbous cluster 60-120 cm tall at the top of the stem. The fruit is fleshy and green, maturing into a leathery, dark brown six-celled capsule 5-11.5 cm long and 3-4 cm broad in late summer.
This yucca typically grows on rocky desert slopes and Creosote desert flats between 300-1200 m altitude, rarely up to 2500 m. They thrive in full sun and in soil with excellent drainage. It also needs no summer water. It is related to the Banana yucca (Y. baccata), which occurs in the same general area; hybrids between the two are sometimes found.
The fibers of the leaves were used by Native Americans to make rope, sandals, and cloth. The flowers and fruit could be eaten and the black seeds were ground into a flour. The roots were used to make soap. Currently extracts from this plant are in animal feed and various herbal medications. Some reports claim that Native Americans washed their hair with yucca to fight dandruff and hair loss. Among the other maladies this yucca has been used to treat are headaches, bleeding, gonorrhea, arthritis and rheumatism. Also used as a natural deodorizer. Used in pet deodorizers. Steroid saponins are produced commercially from Yucca schidigera.
Vitamin E is a generic term for tocopherols which taken from the Greek words tokos, meaning offspring, and phero, meaning to bear, and tocotrienols. Vitamin E is a family of α-, β-, γ-, and δ- (respectively: alpha, beta, gamma, and delta) tocopherols and corresponding four tocotrienols. Vitamin E is a fat-soluble antioxidant that stops the production of reactive oxygen species formed when fat undergoes oxidation. Of these, α-tocopherol (also written as alpha-tocopherol) has been most studied as it has the highest bioavailability.
It has been claimed that α-tocopherol is the most important lipid-soluble antioxidant, and that it protects cell membranes from oxidation by reacting with lipid radicals produced in the lipid peroxidation chain reaction. This would remove the free radical intermediates and prevent the oxidation reaction from continuing. The oxidized α-tocopheroxyl radicals produced in this process may be recycled back to the active reduced form through reduction by other antioxidants, such as ascorbate, retinol or ubiquinol. However, the importance of the antioxidant properties of this molecule at the concentrations present in the body are not clear and it is possible that the reason why vitamin E is required in the diet is unrelated to its ability to act as an antioxidant. Other forms of vitamin E have their own unique properties. For example, γ-tocopherol (also written as gamma-tocopherol) is a nucleophile that can react with electrophilic mutagens.
However, the roles and importance of all of the various forms of vitamin E are presently unclear, and it has even been suggested that the most important function of vitamin E is as a signaling molecule, and that it has no significant role in antioxidant metabolism.
Biotin is a water-soluble B-complex vitamin (vitamin B7) that is composed of a ureido (tetrahydroimidizalone) ring fused with a tetrahydrothiophene ring. A valeric acid substituent is attached to one of the carbon atoms of the tetrahydrothiophene ring. Biotin is a coenzyme in the metabolism of fatty acids and leucine, and it plays a role in gluconeogenesis.
Biotin is necessary for cell growth, the production of fatty acids, and the metabolism of fats and amino acids. It plays a role in the citric acid cycle, which is the process by which biochemical energy is generated during aerobic respiration. Biotin not only assists in various metabolic reactions but also helps to transfer carbon dioxide. Biotin may also be helpful in maintaining a steady blood sugar level.
Biotin is often recommended for strengthening hair and nails. As a consequence, it is found in many cosmetics and health products for the hair and skin, though it cannot be absorbed through the hair or skin itself.
Biotin deficiency is rare, because, in general, intestinal bacteria produce biotin in excess of the body's daily requirements. For that reason, statutory agencies in many countries, for example the USA and Australia, do not prescribe a recommended daily intake of biotin. However, a number of metabolic disorders in which an individual's metabolism of biotin is abnormal exist; in these disorders, megadoses of biotin, far higher than the average daily intake from food, in general, can mitigate symptoms and correct the underlying metabolic disturbance.
Niacin (also known as vitamin B3, nicotinic acid and vitamin PP) is an organic compound with the formula C6H5NO2 and, depending on the definition used, one of the forty to eighty essential human nutrients. This colorless, water-soluble solid is a derivative of pyridine, with a carboxyl group (COOH) at the 3-position. Other forms of vitamin B3 include the corresponding amide, nicotinamide ("niacinamide"), where the carboxyl group has been replaced by a carboxamide group (CONH2), as well as more complex amides and a variety of esters. The terms niacin, nicotinamide, and vitamin B3 are often used interchangeably to refer to any member of this family of compounds, since they have the same biochemical activity. Niacin cannot be directly converted to nicotinamide, but both compounds could be converted to NAD and NADP in vivo. Although the two are identical in their vitamin activity, nicotinamide does not have the same pharmacological effects as niacin, which occur as side effects of niacin's conversion. Nicotinamide does not reduce cholesterol or cause flushing. Nicotinamide may be toxic to the liver at doses exceeding 3 g/day for adults. Niacin is a precursor to NAD+/NADH and NADP+/NADPH, which play essential metabolic roles in living cells. Niacin is involved in both DNA repair, and the production of steroid hormones in the adrenal gland. Niacin is one of five vitamins associated with a pandemic deficiency disease.
Niacin was first described by Hugo Weidel in 1873 in his studies of nicotine. The original preparation remains useful: The oxidation of nicotine using nitric acid. Niacin was extracted from livers by Conrad Elvehjem, who later identified the active ingredient, then referred to as the "pellagra-preventing factor" and the "anti-blacktongue factor." When the biological significance of nicotinic acid was realized, it was thought appropriate to choose a name to dissociate it from nicotine, to avoid the perception that vitamins or niacin-rich food contains nicotine, or that cigarettes contain vitamins. The resulting name 'niacin' was derived from nicotinic acid + vitamin.
Carpenter found in 1951 that niacin in corn is biologically unavailable, and can be released only in very alkaline lime water of pH 11. This process is known as nixtamalization.
Niacin is referred to as vitamin B3 because it was the third of the B vitamins to be discovered. It has historically been referred to as "vitamin PP" or "vitamin P-P".
Pantothenic acid, also called pantothenate or vitamin B5 (a B vitamin), is a water-soluble vitamin. For many animals, pantothenic acid is an essential nutrient. Animals require pantothenic acid to synthesize coenzyme-A (CoA), as well as to synthesize and metabolize proteins, carbohydrates, and fats.
Pantothenic acid is the amide between pantoate and beta-alanine. Its name derives from the Greek pantothen (πάντοθεν) meaning "from everywhere" and small quantities of pantothenic acid are found in nearly every food, with high amounts in whole-grain cereals, legumes, eggs, meat, royal jelly, avocado, and yogurt . It is commonly found as its alcohol analog, the provitamin panthenol, and as calcium pantothenate. Pantothenic acid is an ingredient in some hair and skin care products.
Small quantities of pantothenic acid are found in most foods. The major food source of pantothenic acid is in meats, although the concentration found in food animals' muscles is only about half that in humans' muscles. Whole grains are another good source of the vitamin, but milling often removes much of the pantothenic acid, as it is found in the outer layers of whole grains. Vegetables, such as broccoli and avocados, also have an abundance of the acid. In animal feeds, the most important sources of the vitamin are rice, wheat brans, alfalfa, peanut meal, molasses, yeasts, and condensed fish solutions. The most significant sources of pantothenic acid in nature are coldwater fish ovaries and royal jelly.
A recent study also suggests that gut bacteria in humans can generate pantothenic acid, but this has not yet been proven.
The derivative of pantothenic acid, pantothenol, is a more stable form of the vitamin and is often used as a source of the vitamin in multivitamin supplements. Another common supplemental form of the vitamin is calcium pantothenate. Calcium pantothenate is often used in dietary supplements because, as a salt, it is more stable than pantothenic acid in the digestive tract, allowing for better absorption. Possible benefits of supplementation: Doses of 2 g/day of calcium pantothenate may reduce the duration of morning stiffness, degree of disability, and pain severity in rheumatoid arthritis patients. Although the results are inconsistent, supplementation may improve oxygen utilization efficiency and reduce lactic acid accumulation in athletes.
Vitamin A, a bi-polar molecule formed with bi-polar covalent bonds between carbon and hydrogen, is linked to a family of similarly shaped molecules, the retinoids, which complete the remainder of the vitamin sequence. Its important part is the retinyl group, which can be found in several forms. In foods of animal origin, the major form of Vitamin A is an ester, primarily retinyl palmitate, which is converted to an alcohol (retinol) in the small intestine. Vitamin A can also exist as an aldehyde (retinal), or as an acid (retinoic acid). Precursors to the vitamin (provitamins) are present in foods of plant origin as some of the members of the carotenoid family of compounds. All forms of Vitamin A have a beta-ionone ring to which an isoprenoid chain is attached. This structure is essential for vitamin activity. The orange pigment of carrots - beta-carotene - can be represented as two connected retinyl groups, which are used in the body to contribute to Vitamin A levels. The retinyl group, when attached to a specific protein, is the only primary light absorber in visual perception, and the compound name is related to the retina of the eye. Vitamin A can be found in various forms: Retinol, the form of Vitamin A absorbed when eating animal food sources, is a yellow, fat-soluble, vitamin with importance in vision and bone growth. Since the alcohol form is unstable, the vitamin is usually produced and administered in a form of retinyl acetate or palmitate. Other retinoids, a class of chemical compounds that are related chemically to Vitamin A, are used in medicine. The discovery of Vitamin A may have stemmed from research dating back to 1906, indicating that factors other than carbohydrates, proteins, and fats were necessary to keep cattle healthy. By 1917 one of these substances was independently discovered by Elmer McCollum at the University of Wisconsin-Madison, and Lafayette Mendel and Thomas Burr Osborne at Yale University. Since "water-soluble factor B" (Vitamin B) had recently been discovered, the researchers chose the name "fat-soluble factor A" (Vitamin A). Vitamin A was first synthesized in 1947 by two Dutch chemists, David Adriaan van Dorp and Jozef Ferdinand Arens. As some carotenoids can be converted into Vitamin A, attempts have been made to determine how much of them in the diet is equivalent to a particular amount of retinol, so that comparisons can be made of the benefit of different foods. Unfortunately the situation is confusing because the accepted equivalences have changed. For many years, a system of equivalencies was used in which an international unit (IU) was equal to 0.3 µg of retinol, 0.6 µg of ß-carotene, or 1.2 µg of other provitamin-A carotenoids. Later, a unit called retinol equivalent (RE) was introduced. 1 RE corresponded to 1 µg retinol, 2 µg ß-carotene dissolved in oil (as in supplement pills), 6 µg ß-carotene in normal food (because it is not absorbed as well as from supplements), and 12 µg of either a-carotene or ß-cryptoxanthin in food. However, new research showed that the absorption of provitamin-A carotenoids was only half as much as previously thought, so in 2001 the US Institute of Medicine recommended a new unit, the retinol activity equivalent (RAE). 1 µg RAE corresponds to 1 µg retinol, 2 µg of ß-carotene in oil, 12 µg of "dietary" beta-carotene, or 24 µg of other dietary provitamin-A carotenoids. Because the production of retinol from provitamins by the human body is regulated by the amount of retinol available to the body, the conversions apply strictly only for Vitamin A deficient humans. The absorption of provitamins also depends greatly on the amount of lipids ingested with the provitamin; lipids increase the uptake of the provitamin. The conclusion that can be drawn from the newer research is that fruits and vegetables are not as useful for obtaining Vitamin A as was thought-in other words, the IU's that they were reported to contain were worth much less than the same number of IU's of fat-dissolved supplements. This is important for vegetarians. (Night blindness is prevalent in countries where little meat or Vitamin A-fortified foods are available.) A sample vegan diet for one day that provides sufficient Vitamin A has been published by the Food and Nutrition Board. On the other hand, reference values for retinol or its equivalents, provided by the National Academy of Sciences, have decreased. The RDA (for men) of 1968 was 5000 IU (1500 µg retinol). In 1974 the RDA was set to 1000 RE (1000 µg retinol), whereas now the Dietary Reference Intake is 900 RAE (900 µg or 3000 IU retinol). This is equivalent to 1800 µg of ß-carotene supplement (3000 IU) or 10800 µg of ß-carotene in food (18000 IU).
Riboflavin (E101), also known as Vitamin B2, is an easily absorbed micronutrient with a key role in maintaining health in humans and animals. It is the central component of the cofactors FAD and FMN, and is therefore required by all flavoproteins. As such, Vitamin B2 is required for a wide variety of cellular processes. Like the other B vitamins, it plays a key role in energy metabolism, and is required for the metabolism of fats, ketone bodies, carbohydrates, and proteins. Milk, cheese, leafy green vegetables, liver, kidneys, legumes such as mature soybeans, yeast, mushrooms and almonds are good sources of Vitamin B2, but exposure to light destroys riboflavin. The name "riboflavin" comes from "ribose" and "flavin". Riboflavin is yellow or yellow-orange in color and in addition to being used as a food coloring, it is also used to fortify some foods. It is used in baby foods, breakfast cereals, pastas, sauces, processed cheese, fruit drinks, vitamin-enriched milk products, and some energy drinks. Regarding occurrence and sources of Vitamin B2, Yeast extract is considered to be exceptionally rich in Vitamin B2, and liver and kidney are also rich sources. Wheat bran, eggs, meat, milk, and cheese are important sources in diets containing these foods. Cereal grains contain relatively low concentrations of flavins, but are important sources in those parts of the world where cereals constitute the staple diet. The milling of cereals results in considerable loss (up to 60%) of Vitamin B2, so white flour is enriched by addition of the vitamin. The enrichment of bread and ready-to-eat breakfast cereals contributes significantly to the dietary supply of Vitamin B2. Polished rice is not usually enriched, because the vitamin´s yellow color would make the rice visually unacceptable to the major rice-consumption populations. However, most of the flavins content of the whole brown rice is retained if the rice is steamed prior to milling. This process drives the flavins in the germ and aleurone layers into the endosperm. Free riboflavin is naturally present in foods along with protein-bound FMN and FAD. Bovine milk contains mainly free riboflavin, with a minor contribution from FMN and FAD. In whole milk, 14% of the flavins are bound noncovalently to specific proteins. Egg white and egg yolk contain specialized riboflavin-binding proteins, which are required for storage of free riboflavin in the egg for use by the developing embryo. It is difficult to incorporate riboflavin into many liquid products because it has poor solubility in water, hence the requirement for a more expensive but more soluble form of riboflavin. Riboflavin is generally stable during the heat processing and normal cooking of foods if light is excluded. The alkaline conditions in which riboflavin is unstable are rarely encountered in foodstuffs.
Vitamin B12 is a water-soluble vitamin with a key role in the normal functioning of the brain and nervous system, and for the formation of blood. It is one of the eight B vitamins. It is normally involved in the metabolism of every cell of the body, especially affecting DNA synthesis and regulation, but also fatty acid synthesis and energy production. Vitamin B12 is the name for a class of chemically related compounds, all of which have vitamin activity. It is structurally the most complicated vitamin and it contains the biochemically rare element cobalt. Biosynthesis of the basic structure of the vitamin can only be accomplished by bacteria, but conversion between different forms of the vitamin can be accomplished in the human body. A common synthetic form of the vitamin, cyanocobalamin, does not occur in nature, but is used in many pharmaceuticals, supplements and as food additives, due to its stability and lower cost. In the body it is converted to the physiological forms, methylcobalamin and adenosylcobalamin, leaving behind the cyanide, albeit in minimal concentration. More recently, hydroxocobalamin, methylcobalamin and, adenosylcobalamin can also be found in more expensive pharmacological products and food supplements. The utility of these is presently debated. Historically, Vitamin B12 was discovered from its relationship to the disease pernicious anemia, which is an autoimmune disease that destroys parietal cells in the stomach that secrete intrinsic factor. Intrinsic factor is crucial for the normal absorption of B12, therefore, a lack of intrinsic factor, as seen in pernicious anemia, causes a Vitamin B12 deficiency. Many other subtler kinds of Vitamin B12 deficiency, and their biochemical effects, have since been elucidated.
Thiamine, or thiamin, sometimes called aneurin, is a water-soluble vitamin of the B complex (Vitamin B1), whose phosphate derivatives are involved in many cellular processes. The best-characterized form is thiamine diphosphate (ThDP), a coenzyme in the catabolism of sugars and amino acids. In yeast, ThDP is also required in the first step of alcoholic fermentation. Thiamine is synthesized in bacteria, fungi and plants. Animals must cover all their needs from their food and insufficient intake results in a disease called beriberi affecting the peripheral nervous system (polyneuritis) and/or the cardiovascular system, with fatal outcome if not cured by thiamine administration. In less severe deficiency, nonspecific signs include malaise, weight loss, irritability and confusion. Today, there is still a lot of work devoted to elucidating the exact mechanisms by which thiamine deficiency leads to the specific symptoms observed. Finally, new thiamine phosphate derivatives have recently been discovered, emphasizing the complexity of thiamine metabolism and the need for more research in the field. Thiamine is found in a wide variety of foods at low concentrations. Yeast and pork are the most highly concentrated sources of thiamine. Cereal grains, however, are generally the most important dietary sources of thiamine, by virtue of their ubiquity. Of these, whole grains contain more thiamine than refined grains, as thiamine is found mostly in the outer layers of the grain and in the germ (which are removed during the refining process). For example, 100 g of whole wheat flour contains 0.55 mg of thiamine, while 100 g of white flour only contains 0.06 mg of thiamine. In the US, processed flour must be enriched with thiamine mononitrate (along with niacin, ferrous iron, riboflavin and folic acid) to replace that lost in processing. Some other foods rich in thiamine are oatmeal, flax and Sunflower seeds, brown rice, whole grain rye, asparagus, kale, cauliflower, potatoes, oranges, liver (beef, pork and chicken) and eggs.
Pyridoxine assists in the balancing of sodium and potassium as well as promoting red blood cell production. It is linked to cardiovascular health by decreasing the formation of homocysteine. It has been suggested that Pyridoxine might help children with learning difficulties, and may also prevent dandruff, eczema, and psoriasis. In addition, pyridoxine can help balance hormonal changes in women and aid in the immune system. Lack of pyridoxine may cause anemia, nerve damage, seizures, skin problems, and sores in the mouth. It is required for the production of the monoamine neurotransmitters serotonin, dopamine, norepinephrine and epinephrine, as it is the precursor to pyridoxal phosphate: cofactor for the enzyme aromatic amino acid decarboxylase. This enzyme is responsible for converting the precursors 5-hydroxytryptophan (5-HTP) into serotonin and levodopa (L-DOPA) into dopamine, noradrenaline and adrenaline. As such it has been implicated in the treatment of depression and anxiety. A very good source of pyridoxine is dragon fruit from South East Asia. Pyridoxine is not normally found in plants and plants are not the principal source of this vitamin. This vitamin is made by certain bacteria. Some vegetarians may get adequate pyridoxine simply from eating plants that have traces of soil (like potato skins). Most people get their supply of this vitamin from either milk or meat products.
Citric acid is a weak organic acid, is a natural preservative and is also used to add an acidic, or sour, taste to foods and soft drinks. In biochemistry, it is important as an intermediate in the citric acid cycle and therefore occurs in the metabolism of virtually all living things. It can also be used as an environmentally benign cleaning agent and acts as an antioxidant and a lubricant. Citric acid exists in greater than trace amounts in a variety of fruits and vegetables, most notably citrus fruits. Lemons and limes have particularly high concentrations of the acid; it can constitute as much as 8% of the dry weight of these fruits (1.44 and 1.38 grams per ounce of the juices, respectively). The concentrations of citric acid in citrus fruits range from .005 mol/L for oranges and grapefruits to .030 mol/L in lemons and limes. These values vary depending on the circumstances in which the fruit was grown. As a food additive, citric acid is used as a flavoring and preservative in food and beverages, especially soft drinks. It is denoted by E number E330. Citrate salts of various metals are used to deliver those minerals in a biologically available form in many dietary supplements. The buffering properties of citrates are used to control pH in household cleaners and pharmaceuticals. In the United States the purity requirements for citric acid as a food additive are defined by the Food Chemical Codex (FCC), which is published by the United States Pharmacopoeia (USP).
Vitamin D is a group of fat-soluble prohormones, the two major forms of which are Vitamin D2 (or ergocalciferol) and Vitamin D3 (or cholecalciferol). The term Vitamin D also refers to metabolites and other analogues of these substances. Vitamin D3 is produced in skin exposed to sunlight, specifically ultraviolet B radiation. Vitamin D plays an important role in the maintenance of organ systems. Vitamin D regulates the calcium and phosphorus levels in the blood by promoting their absorption from food in the intestines, and by promoting reabsorption of calcium in the kidneys, which enables normal mineralization of bone and prevents hypocalcemic tetany. It is also needed for bone growth and bone remodeling by osteoblasts and osteoclasts. In the absence of Vitamin K or with drugs (particularly blood thinners) that interfere with Vitamin K metabolism, Vitamin D can promote soft tissue calcification. It inhibits parathyroid hormone secretion from the parathyroid gland. Vitamin D affects the immune system by promoting phagocytosis, anti-tumor activity, and immunomodulatory functions.
Vitamin D deficiency can result from inadequate intake coupled with inadequate sunlight exposure; disorders that limit its absorption; conditions that impair conversion of Vitamin D into active metabolites, such as liver or kidney disorders; or, rarely, by a number of hereditary disorders. Deficiency results in impaired bone mineralization and leads to bone softening diseases; rickets in children and osteomalacia in adults, and possibly contributes to osteoporosis. However, sunlight exposure, to avoid deficiency, carries other risks, including skin cancer; this risk is avoided with dietary absorption, either through diet or as a dietary supplement. Vitamin D is naturally produced by the human body when exposed to direct sunlight. Season, geographic latitude, time of day, cloud cover, smog, and sunscreen affect UV ray exposure and Vitamin D synthesis in the skin, and it is important for individuals with limited sun exposure to include good sources of Vitamin D in their diet. Extra Vitamin D is also recommended for older adults and people with dark skin. Individuals with a high-risk of deficiency should consume 25 µg (1000 IU) of Vitamin D daily to maintain adequate blood concentrations of 25-hydroxyvitamin D. As civilization and the Industrial Revolution enabled humans to work indoors and wear more clothes when in the sun, these cultural changes reduced natural production of Vitamin D and caused deficiency diseases. In many countries, foods such as milk, yogurt, margarine, oil spreads, breakfast cereal, pastries, and bread are fortified with Vitamin D2 and/or Vitamin D3, to minimize the risk of Vitamin D deficiency. In the United States and Canada, for example, fortified milk typically provides 100 IU per glass, or one quarter of the estimated adequate intake for adults over the age of 50. Supplementation of 100 IU (2.5 microgram) Vitamin D3 raises blood calcidiol levels by 2.5 nmol/litre (1 ng/ml). Fatty fish, such as salmon, are natural sources of Vitamin D. Natural sources of Vitamin D include:
- Fish liver oils, such as cod liver oil, 1 Tbsp. (15 mL) provides 1,360 IU (one IU equals 25 ng)
- Fatty fish species, such as:
- Herring, 85 g (3 ounces (oz)) provides 1383 IU
- Catfish, 85 g (3 oz) provides 425 IU
- Salmon, cooked, 100 g (3.5 oz) provides 360 IU
- Mackerel, cooked, 100 g (3.5 oz), 345 IU
- Sardines, canned in oil, drained, 50 g (1.75 oz), 250 IU
- Tuna, canned in oil, 85 g (3 oz), 200 IU
- Eel, cooked, 100 g (3.5 oz), 200 IU
- One whole egg, provides 20 IU
- Beef liver, cooked, 100 g (3.5 oz), provides 15 IU
- UV-irradiated mushrooms (Vitamin D2)
The practical reality is that on average, the U.S. diet provides 100 IU/day. One problem is that much of the fortified milk is not fortified to the required amount. Adequate Intake is defined as 200 IU/day for ages infant to 50, 400/day for 51-70, and 600/day for >70. The 100% Daily Value used for product labels is 400 IU. The safe upper limit is set at 2000 IU. The Institute Of Medicine is revisiting Vitamin D and calcium recommendations. The report is expected Spring 2010.
Folic acid (also known as Vitamin B9 or Folacin) and Folate (the naturally occurring form) are forms of the water-soluble Vitamin B9. Vitamin B9 (Folic acid and Folate inclusive) is essential to numerous bodily functions ranging from nucleotide synthesis to the remethylation of homocysteine. It is especially important during periods of rapid cell division and growth. Both children and adults require folic acid to produce healthy red blood cells and prevent anemia. Folate and Folic acid derive their names from the Latin word folium (leaf). Leafy vegetables such as spinach, asparagus, turnip greens, lettuces, dried/fresh beans and peas, fortified cereal products, sunflower seeds and certain other fruits and vegetables are rich sources of folate. Liver and liver products also contain high amounts of folate, as does baker's yeast. Some breakfast cereals (ready-to-eat and others) are fortified with 25% to 100% of the recommended dietary allowance (RDA) for folic acid. A table of selected food sources of folate and folic acid can be found at the USDA National Nutrient Database for Standard Reference. Folic acid is added to grain products in many countries, and in these countries fortified products make up a significant source of folate. Because of the difference in bioavailability between supplemented folic acid and the different forms of folate found in food, the dietary folate equivalent (DFE) system was established. 1 DFE is defined as 1 µg of dietary folate, or 0.6 µg of folic acid supplement. This is reduced to 0.5 µg of folic acid if the supplement is taken on an empty stomach.
Iron(II) sulfate (Iron(II) sulphate) or ferrous sulfate (ferrous sulphate) is the chemical compound with the formula (FeSO4), known since ancient times as copperas. It is most commonly encountered as the blue-green heptahydrate. Together with other iron compounds, ferrous sulfate is used to fortify foods and to treat iron-deficiency anemia. Copperas was given indiscriminately, by untrained persons, to slaves in the 18th and 19th centuries for various ailments. Constipation is a frequent and uncomfortable side effect associated with the administration of oral iron supplements. Stool softeners often are prescribed to prevent constipation.
Zinc sulfate (ZnSO4) is a colorless crystalline, water-soluble chemical compound. The hydrated form, ZnSO4o7H2O, the mineral goslarite, was historically known as "white vitriol" and can be prepared by reacting zinc with aqueous sulfuric acid. It may also be prepared by adding solid zinc to a copper(II) sulfate solution.
It is used to supply zinc in animal feeds, fertilizers, and agricultural sprays. ZnSO4o7H2O is used in making lithopone, in coagulation baths for rayon, in electrolytes for zinc plating, as a mordant in dyeing, as a preservative for skins and leather and in medicine as an astringent and emetic.
Another natural form of this heptahydrate is known as mineral zincmelanterite (Zn,Cu,Fe)SO4o7H2O (structurally different from goslarite). Lower hydrates of zinc sulfate are rarely found in nature as minerals: bianchite (Zn,Fe)SO4o6H2O, boyleite (Zn,Mg)SO4o4H2O and gunningite (Zn,Mn)SO4oH2O.
Zinc proteinate is the final product resulting from the chelation of zinc with amino acids and/or partially hydrolyzed proteins. It is used as a nutritional animal feed supplement formulated to prevent and/or correct zinc deficiency in animals. Zinc proteinate can be used in place of zinc sulfate and zinc methionine.
Good sources of dietary iron include red meat, fish, poultry, lentils, beans, leaf vegetables, tofu, chickpeas, black-eyed peas, fortified bread, and fortified breakfast cereals. Iron in low amounts is found in molasses, teff and farina. Iron in meat (haem iron) is more easily absorbed than iron in vegetables, but haem/hemoglobin from red meat has effects that may increase the likelihood of colorectal cancer. Iron provided by dietary supplements is often found as iron (II) fumarate, although iron sulfate is cheaper and is absorbed equally well. Elemental iron, despite being absorbed to a much smaller extent (stomach acid is sufficient to convert some of it to ferrous iron), is often added to foods such as breakfast cereals or "enriched" wheat flour (where it is listed as "reduced iron" in the list of ingredients). Iron is most available to the body when chelated to amino acids - iron in this form is ten to fifteen times more bioavailable than any other, and is also available for use as a common iron supplement. Often the amino acid chosen for this purpose is the cheapest and most common amino acid, glycine, leading to "iron glycinate" supplements. The RDA for iron varies considerably based on age, gender, and source of dietary iron (haem-based iron has higher bioavailability). Infants may require iron supplements if they are breast-fed. Blood donors and pregnant women are at special risk of low iron levels and are often advised to supplement their iron intake.
Zinc oxide is an inorganic compound with the formula ZnO. It usually appears as a white powder, nearly insoluble in water. The powder is widely used as an additive into numerous materials and products including plastics, ceramics, glass, cement, rubber (e.g. car tires), lubricants, paints, ointments, adhesives, sealants, pigments, foods (source of Zn nutrient), batteries, ferrites, fire retardants, etc. ZnO is present in the Earth crust as a mineral zincite; however, most ZnO used commercially is produced synthetically. In materials science, ZnO is often called a II-VI semiconductor because zinc and oxygen belong to the 2nd and 6th groups of the periodic table, respectively. This semiconductor has several favorable properties: good transparency, high electron mobility, wide bandgap, strong room-temperature luminescence, etc. Those properties are already used in emerging applications for transparent electrodes in liquid crystal displays and in energy-saving or heat-protecting windows, and electronic applications of ZnO as thin-film transistor and light-emitting diode are forthcoming as of 2009. As a food additive, Zinc oxide is on FDA's generally recognized as safe, or GRAS, substances.
Copper(II) sulfate is the chemical compound with the formula CuSO4. This salt exists as a series of compounds that differ in their degree of hydration. The anhydrous form is a pale green or gray-white powder, whereas the pentahydrate, the most commonly encountered salt, is bright blue. The anhydrous form occurs as a rare mineral known as chalcocyanite. The hydrated copper sulfate occurs in nature as chalcanthite (pentahydrate), and two more rare ones: bonattite (trihydrate) and boothite (heptahydrate). Archaic names for copper(II) sulfate are "blue vitriol" and "bluestone."
Manganese sulfate is the inorganic compound with the formula MnSO4. This colorless deliquescent solid is a commercially significant manganese(II) salt. Approximately 260M kg/y were produced worldwide in 2005. It is the precursor to manganese metal and many chemical compounds. Mn-deficient soil is remediated with this salt. Like many metal sulfates, manganese sulfate forms a variety of hydrates: monohydrate, tetrahydrate, pentahydrate, and heptahydrate. The monohydrate is most common. All of these salts are faintly pink. The pale color of Mn(II) salts is characteristic of high-spin complexes with the d5 configuration.
Manganese is an essential trace nutrient in all forms of life. The classes of enzymes that have manganese cofactors are very broad and include such classes as oxidoreductases, transferases, hydrolases, lyases, isomerases, ligases, lectins, and integrins. The reverse transcriptases of many retroviruses (though not lentiviruses such as HIV) contain manganese. The best known manganese-containing polypeptides may be arginase, the diphtheria toxin, and Mn-containing superoxide dismutase (Mn-SOD). Mn-SOD is the type of SOD present in eukaryotic mitochondria, and also in most bacteria (this fact is in keeping with the bacterial-origin theory of mitochondria). The Mn-SOD enzyme is probably one of the most ancient, for nearly all organisms living in the presence of oxygen use it to deal with the toxic effects of superoxide, formed from the 1-electron reduction of dioxygen. Exceptions include a few kinds of bacteria such as Lactobacillus plantarum and related lactobacilli, which use a different non-enzymatic mechanism, involving manganese (Mn2+) ions complexed with polyphosphate directly for this task, indicating how this function possibly evolved in aerobic life. The human body contains about 10 mg of manganese, which is stored mainly in the liver and kidneys. In the human brain the manganese is bound to manganese metalloproteins most notable glutamine synthetase in astrocytes. Manganese is also important in photosynthetic oxygen evolution in chloroplasts in plants. The oxygen evolving complex (OEC) is a part of Photosystem II contained in the thylakoid membranes of chloroplasts; it is responsible for the terminal photooxidation of water during the light reactions of photosynthesis and has a metalloenzyme core containing four atoms of manganese. For this reason, most broad-spectrum plant fertilizers contain manganese.
Copper is essential in all plants and animals. The human body normally contains copper at a level of about 1.4 to 2.1 mg for each kg of body weight. Copper is distributed widely in the body and occurs in liver, muscle and bone. Copper is transported in the bloodstream on a plasma protein called ceruloplasmin. When copper is first absorbed in the gut it is transported to the liver bound to albumin. Copper metabolism and excretion is controlled delivery of copper to the liver by ceruloplasmin, where it is excreted in bile. Copper is found in a variety of enzymes, including the copper centers of cytochrome c oxidase and the enzyme superoxide dismutase (containing copper and zinc). In addition to its enzymatic roles, copper is used for biological electron transport. The blue copper proteins that participate in electron transport include azurin and plastocyanin. The name "blue copper" comes from their intense blue color arising from a ligand-to-metal charge transfer (LMCT) absorption band around 600 nm. Most molluscs and some arthropods such as the horseshoe crab use the copper-containing pigment hemocyanin rather than iron-containing hemoglobin for oxygen transport, so their blood is blue when oxygenated rather than red. It is believed that zinc and copper compete for absorption in the digestive tract so that a diet that is excessive in one of these minerals may result in a deficiency in the other. The RDA for copper in normal healthy adults is 0.9 mg/day. On the other hand, professional research on the subject recommends 3.0 mg/day. Because of its role in facilitating iron uptake, copper deficiency can often produce anemia-like symptoms. In humans, the symptoms of Wilson's disease are caused by an accumulation of copper in body tissues. Chronic copper depletion leads to abnormalities in metabolism of fats, high triglycerides, non-alcoholic steatohepatitis (NASH), fatty liver disease and poor melanin and dopamine synthesis causing depression and sunburn. Food rich in copper should be eaten away from any milk or egg proteins as they block absorption.
Manganese oxide is a generic term used to describe a variety of manganese oxides and hydroxides. It may refer to:
- Manganese(II) oxide, MnO
- Manganese(II,III) oxide, Mn3O4
- Manganese(II,IV) oxide, Mn5O8
- Manganese(III) oxide, Mn2O3
- Manganese dioxide, (manganese(IV) oxide), MnO2
- Manganese trioxide, (manganese(VI) oxide), MnO3
Manganese(VII) oxide, Mn2O7 Manganese dioxide is the inorganic compound with the formula MnO2. This blackish or brown solid occurs naturally as the mineral pyrolusite, which is the main ore of manganese. It is also present in manganese nodules. The principal use for MnO2 is for dry-cell batteries, such as the alkaline battery and the zinc-carbon battery. In 1976 this application accounted for 500,000 tonnes of pyrolusite. MnO2 is also used for production of MnO4-. It is used extensively as an oxidizing agent in organic synthesis, for example, for the oxidation of allylic alcohols.
Selenium (pronounced /sə-li-niəm/) is a chemical element with the atomic number 34, represented by the chemical symbol Se, an atomic mass of 78.96. It is a nonmetal, chemically related to sulfur and tellurium, and rarely occurs in its elemental state in nature. Isolated selenium occurs in several different forms, the most stable of which is a dense purplish-gray semi-metal (semiconductor) form that is structurally a trigonal polymer chain. It conducts electricity better in the light than in the dark, and is used in photocells. Selenium also exists in many non-conductive forms: a black glass-like allotrope, as well as several red crystalline forms built of eight-membered ring molecules, like its lighter chemical cousin sulfur.
Selenium is found in economic quantities in sulfide ores such as pyrite, partially replacing the sulfur in the ore matrix. Minerals that are selenide or selenate compounds are also known, but all are rare. The chief commercial present uses for selenium are in glassmaking and in chemicals and pigments. Electronic uses for selenium, once important, have been supplanted by silicon semiconductor devices. Selenium salts are toxic in large amounts, but trace amounts of the element are necessary for cellular function in most, if not all, animals, forming the active center of the enzymes glutathione peroxidase and thioredoxin reductase (which indirectly reduce certain oxidized molecules in animals and some plants) and three known deiodinase enzymes (which convert one thyroid hormone to another). Selenium requirements in plants differ by species, with some plants apparently requiring none. Although it is toxic in large doses, selenium is an essential micronutrient for animals. In plants, it occurs as a bystander mineral, sometimes in toxic proportions in forage (some plants may accumulate selenium as a defense against being eaten by animals, but other plants such as locoweed require selenium, and their growth indicates the presence of selenium in soil). It is a component of the unusual amino acids selenocysteine and selenomethionine. In humans, selenium is a trace element nutrient which functions as cofactor for reduction of antioxidant enzymes such as glutathione peroxidases and certain forms of thioredoxin reductase found in animals and some plants (this enzyme occurs in all living organisms, but not all forms of it in plants require selenium). Glutathione peroxidase (GSH-Px) catalyzes certain reactions that remove reactive oxygen species such as peroxide:
2 GSH+H2O2---------GSH-Px -> GSSG + 2 H2O.
Selenium also plays a role in the functioning of the thyroid gland by participating as a cofactor for the three known thyroid hormone deiodinases. Dietary selenium comes from nuts, cereals, meat, fish, and eggs. Brazil nuts are the richest ordinary dietary source (though this is soil-dependent, since the Brazil nut does not require high levels of the element for its own needs). High levels are found in kidney, tuna, crab and lobster, in that order.
Calcium iodate (also called lautarite) is a compound of calcium and iodate anion. It is used as a dough conditioner. Calcium iodate is an oxidant added to lotions and ointments as an antiseptic and deodorant.
Vitamin E is the collective name for a set of 8 related α-, β-, γ-, and δ-tocopherols and the corresponding four tocotrienols, which are fat-soluble vitamins with antioxidant properties. Of these, α-tocopherol (also written as alpha-tocopherol) has been most studied as it has the highest bioavailability. It has been claimed that α-tocopherol is the most important lipid-soluble antioxidant, and that it protects cell membranes from oxidation by reacting with lipid radicals produced in the lipid peroxidation chain reaction. This would remove the free radical intermediates and prevent the oxidation reaction from continuing. The oxidized α-tocopheroxyl radicals produced in this process may be recycled back to the active reduced form through reduction by other antioxidants, such as ascorbate, retinol or ubiquinol. However, the importance of the antioxidant properties of this molecule at the concentrations present in the body are not clear and it is possible that the reason why Vitamin E is required in the diet is unrelated to its ability to act as an antioxidant. Other forms of Vitamin E have their own unique properties. For example, γ-tocopherol (also written as gamma-tocopherol) is a nucleophile that may react with electrophilic mutagens. Tocotrienols have specialized roles in protecting neurons from damage, cancer prevention and cholesterol reduction by inhibiting the activity of HMG-CoA reductase; δ-tocotrienol blocks processing of sterol regulatory element-binding proteins (SREBPs). However, the roles and importance of all of the various forms of Vitamin E are presently unclear, and it has even been suggested that the most important function of Vitamin E is as a signaling molecule, and that it has no significant role in antioxidant metabolism.