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Helix (genus)
Encyclopedia
Helix is a genus
of large air-breathing land snails, terrestrial
pulmonate
gastropod molluscs. This genus is native to Europe
and the regions around the Mediterranean Sea
. Helix is the type genus
of the family Helicidae
.
The best-known species
include Helix aspersa
, the common, or brown garden snail, and Helix pomatia
, the Roman snail, Burgundy snail, or edible snail. H. pomatia
and some other species are eaten as escargots.
Helix snails have been introduced throughout the world, where some, especially H. aspersa, have become garden pests.
The genus Helix is known from the Oligocene
on.
Snails in this genus create and use love dart
s during mating.
Subgenus Helix
Subgenus Pelasga
Subgenus Cornu
Subgenus ?
Some taxonomists remove the species "Helix aperta", "Helix aspersa", and "Helix mazzullii" from the genus Helix and place them in their own monotypic genera as Cantareus apertus, Cornu aspersum and Cantareus mazzullii
.
At the beginning in the mid-1700s the generic name Helix had been used for almost all terrestrial gastropods, later this was restricted to species with helicoid habitus, including zonitids and other groups. In the course of the 1800s more groups were removed, but prior to 1900 several thousand helicid and hygromiid species of Europe and abroad had still been classified in the genus Helix. It was only in the early 1900s that the genus was split up into many separate genera, leaving only some 30 species closely related to its type species Helix pomatia
in the genus Helix.
In addition to the hard calcareous shell that covers and protects the internal organs, the head and foot region can be observed when the snails are fully extended. When they are active, the organs such as the lung
, heart
, kidney
and intestines remain inside the shell; only the head and foot emerge.
The head of the snail has two pairs of tentacles: the upper and larger pair contain the eyes, and the lower pair are used to feel the ground in front. The mouth is located just underneath the head. The tentacles can be withdrawn or extended depending on the situation. The mouth has a tongue
called a "radula
" that is composed of many fine chitinous teeth. This serves for rasping and cutting food.
, meaning that both female and male sexual organs are present in the same individual. The snails produce both eggs
and sperm
in the ovotestis (also called the hermaphrodite gland), but it is later separated into two divisions, a sperm duct and oviduct
, respectively.
Mating
takes several hours, sometimes a day. H. aspersa snails stab a calcite spine, known as a "love dart
", at their partner. The love dart is coated with a mucus that contains a chemical that enables more than twice as many sperm to survive inside the recipient. A few days after mating, the eggs are laid in the soil. The eggs are usually 4–6 mm in diameter.
After snails hatch from the egg, they mature in one or more years, depending on where the organism lives. Maturity takes two years in Southern California
, while it takes only ten months in South Africa
.
The size of the adult snails slightly varies with species. H. aspersa grows up to 35 mm in height and width, whereas H. pomatia grows up to 45 mm. The life span of snails in the wild is on average two or three years.
Some snails may live longer, perhaps even 30 years or older in the case of the Roman snail but most live less than 8 years. Many deaths are due to predators and parasites.
The garden snail is a relatively fast snail. It has been observed to reach speeds of up to 1.3 cm/s.
s,instead.)
Oxygen
is carried by the blood pigment hemocyanin
. Both oxygen and carbon dioxide
diffuse in and out of blood through the capillaries. A muscular
valve regulates the process of opening and closing the entrance of the lung. When the valve opens, the air can either leave or come into the lung. The valve plays an important role in reducing water loss and preventing drowning.
or other hiding places, to avoid being discovered by predators. In dry climate
s snails will naturally congregate near water sources, including artificial sources such as waste-water outlets of air conditioners.
The common garden snail (Helix aspersa) is herbivorous
. These snails are able to digest most vegetation including carrot
s and lettuce
. They also have a specialized crop of symbiotic bacteria
that aid in their digestion, especially with the breakdown of the polysaccharide cellulose
into simple sugars.
Many predators, both specialist and generalist, feed on snails. Some animals, such as the song thrush
, break the shell of the snail by hammering it against a hard object, such as stone, in order to expose its edible insides. Other predators, such as some species of frog
s, circumvent the need to break snail shells by simply swallowing the snail whole, shell and all.
Some carnivorous species of snails, such as the decollate snail
and the rosy wolf snail, also prey on Helix snails. Such carnivorous snails are commercially grown and sold in order to combat pest snail species. Many of these also escape into the wild, where they prey on indigenous snails, such as the Cuban land snails of the genus Polymita
, and the indigenous snails of Hawaii
.
. Spanish cuisine also uses Otala punctata
, Theba pisana
and Iberus gualterianus alonensis, amongst others. The process of snail farming is called heliciculture
.
Escargots are often served in a traditional way as appetizers. They may also be used as ingredients in other recipes.
Snails contain many nutrients. They are rich in calcium
and also contain vitamin B1 and E
. They contain various essential amino acid
s, and are low in calorie
s and fat
.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of large air-breathing land snails, terrestrial
Terrestrial animal
Terrestrial animals are animals that live predominantly or entirely on land , as compared with aquatic animals, which live predominantly or entirely in the water , or amphibians, which rely on a combination of aquatic and terrestrial habitats...
pulmonate
Pulmonata
The Pulmonata, or "pulmonates", are an informal group of snails and slugs characterized by the ability to breathe air, by virtue of having a pallial lung instead of a gill, or gills...
gastropod molluscs. This genus is native to Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
and the regions around the Mediterranean Sea
Mediterranean Sea
The Mediterranean Sea is a sea connected to the Atlantic Ocean surrounded by the Mediterranean region and almost completely enclosed by land: on the north by Anatolia and Europe, on the south by North Africa, and on the east by the Levant...
. Helix is the type genus
Type genus
In biological classification, a type genus is a representative genus, as with regard to a biological family. The term and concept is used much more often and much more formally in zoology than it is in botany, and the definition is dependent on the nomenclatural Code that applies:* In zoological...
of the family Helicidae
Helicidae
The Helicidae, sometimes known as the typical snails, are a taxonomic family of small to large, air-breathing, land snails. In other words, they are terrestrial pulmonate gastropod mollusks....
.
The best-known species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
include Helix aspersa
Helix aspersa
Helix aspersa, known by the common name garden snail, is a species of land snail, a pulmonate gastropod that is one of the best-known of all terrestrial molluscs. The species has been placed in the genus Helix, in all sources between 1774 and 1988 and in most sources until recently...
, the common, or brown garden snail, and Helix pomatia
Helix pomatia
Helix pomatia, common names the Burgundy snail, Roman snail, edible snail or escargot, is a species of large, edible, air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Helicidae...
, the Roman snail, Burgundy snail, or edible snail. H. pomatia
Helix pomatia
Helix pomatia, common names the Burgundy snail, Roman snail, edible snail or escargot, is a species of large, edible, air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Helicidae...
and some other species are eaten as escargots.
Helix snails have been introduced throughout the world, where some, especially H. aspersa, have become garden pests.
The genus Helix is known from the Oligocene
Oligocene
The Oligocene is a geologic epoch of the Paleogene Period and extends from about 34 million to 23 million years before the present . As with other older geologic periods, the rock beds that define the period are well identified but the exact dates of the start and end of the period are slightly...
on.
Snails in this genus create and use love dart
Love dart
A love dart is a hard, long, sharp, calcareous or chitinous dart which some hermaphroditic land snails and slugs create. Love darts are made in sexually mature animals only, and are used as part of the sequence of events during courtship, before actual mating takes place...
s during mating.
Species
Subgenera and species within the genus Helix include today:Subgenus Helix
- Helix albescens Rossmaessler, 1839
- Helix lucorumHelix lucorumHelix lucorum is a species of large, edible, air-breathing land snail or escargot, a terrestrial pulmonate gastropod mollusk in the family Helicidae, the typical snails.- Synonyms :Numerous synonyms exist for Helix lucorum:...
Linnaeus, 1758 - Helix pomatiaHelix pomatiaHelix pomatia, common names the Burgundy snail, Roman snail, edible snail or escargot, is a species of large, edible, air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Helicidae...
Linnaeus, 1758 - Burgundy Snail, Roman Snail, Edible Snail - Helix philibinensis Rossmässler, 1839
Subgenus Pelasga
- Helix pomacella Mousson, 1854
- Helix figulina Rossmässler, 1839
Subgenus Cornu
Cornu
Cornu is a Latin word for horn.Cornu may also refer to:*Cornu , an ancient musical instrumentPeople:*Dominique Cornu, a Belgian road and track cyclist, born 1985....
- Helix aspersaHelix aspersaHelix aspersa, known by the common name garden snail, is a species of land snail, a pulmonate gastropod that is one of the best-known of all terrestrial molluscs. The species has been placed in the genus Helix, in all sources between 1774 and 1988 and in most sources until recently...
Müller, 1774 - brown garden snail or common garden snail also known as Cantareus aspersus and Cornu aspersus
Subgenus ?
- Helix apertaHelix apertaHelix aperta, also known as Cantareus apertus, and commonly known as the green garden snail, is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Helicidae, the typical snails.-Distribution:...
Born, 1778 - Helix engaddensisHelix engaddensisHelix engaddensis is a species of snail common in the Levant, both in Mediterranean, desert and montane climates. It is smaller than the closely related European Garden snail and usually lighter in color. H. engaddensis goes through estivation. It is dormant in the ground during the dry season and...
Bourguinat, 1852 - Levantine field snail - Helix buchi Dubois de Montpéreux, 1839 (largest species of the genus Helix, a synonym is Helix goderdzianaHelix goderdzianaHelix goderdziana is a species of large air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Helicidae, the typical snail.This is the largest species in the genus Helix.- Distribution :...
Mumladze, Tarkhnishvili & Pokryszko, 2008). - Helix godetianaHelix godetianaHelix godetiana is a species of large, air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Helicidae, the typical snails. This species is endemic to Greece.- External links :*...
- † Helix insignis - late MioceneMioceneThe Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...
- Helix lutescensHelix lutescensHelix lutescens is species of air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Helicidae, the true snails.This species of snail creates and uses calcareous love darts.-Distribution:...
Rossmässler, 1837 - Helix mazzullii - also known as Cantareus mazzulliiCantareus mazzulliiHelix mazzullii, also known as Cantareus mazzullii or Cornu mazzullii, is a species of large, edible, air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Helicidae, the typical snails....
- Helix melanostomaHelix melanostomaHelix melanostoma is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Helicidae, the typical snails.-External links:* http://www.animalbase.uni-goettingen.de/zooweb/servlet/AnimalBase/home/species?id=1602...
DraparnaudJacques Philippe Raymond DraparnaudJacques Philippe Raymond Draparnaud was a French naturalist, malacologist and botanist.Draparnaud is considered the father of malacology in France...
, 1801 - Helix obrutaHelix obrutaHelix obruta is a species of large, edible, air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Helicidae, the typical snails. This species is endemic to Portugal.-References:...
Morelet, 1860 - Helix textaHelix textaHelix texta is a species of large, edible, air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Helicidae, the typical snails. This species is endemic to Israel.The size of the egg is 5.5 mm....
Mousson, 1861
Some taxonomists remove the species "Helix aperta", "Helix aspersa", and "Helix mazzullii" from the genus Helix and place them in their own monotypic genera as Cantareus apertus, Cornu aspersum and Cantareus mazzullii
Cantareus mazzullii
Helix mazzullii, also known as Cantareus mazzullii or Cornu mazzullii, is a species of large, edible, air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Helicidae, the typical snails....
.
At the beginning in the mid-1700s the generic name Helix had been used for almost all terrestrial gastropods, later this was restricted to species with helicoid habitus, including zonitids and other groups. In the course of the 1800s more groups were removed, but prior to 1900 several thousand helicid and hygromiid species of Europe and abroad had still been classified in the genus Helix. It was only in the early 1900s that the genus was split up into many separate genera, leaving only some 30 species closely related to its type species Helix pomatia
Helix pomatia
Helix pomatia, common names the Burgundy snail, Roman snail, edible snail or escargot, is a species of large, edible, air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Helicidae...
in the genus Helix.
External features
Lung
The lung is the essential respiration organ in many air-breathing animals, including most tetrapods, a few fish and a few snails. In mammals and the more complex life forms, the two lungs are located near the backbone on either side of the heart...
, heart
Heart
The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...
, kidney
Kidney
The kidneys, organs with several functions, serve essential regulatory roles in most animals, including vertebrates and some invertebrates. They are essential in the urinary system and also serve homeostatic functions such as the regulation of electrolytes, maintenance of acid–base balance, and...
and intestines remain inside the shell; only the head and foot emerge.
The head of the snail has two pairs of tentacles: the upper and larger pair contain the eyes, and the lower pair are used to feel the ground in front. The mouth is located just underneath the head. The tentacles can be withdrawn or extended depending on the situation. The mouth has a tongue
Tongue
The tongue is a muscular hydrostat on the floors of the mouths of most vertebrates which manipulates food for mastication. It is the primary organ of taste , as much of the upper surface of the tongue is covered in papillae and taste buds. It is sensitive and kept moist by saliva, and is richly...
called a "radula
Radula
The radula is an anatomical structure that is used by molluscs for feeding, sometimes compared rather inaccurately to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food enters the esophagus...
" that is composed of many fine chitinous teeth. This serves for rasping and cutting food.
Behaviour
From April through the northern summer, the number of snails copulating increases due to the higher temperature and humidity, which enhance the possibility of oviposition. The pulmonate snails are hermaphroditicHermaphrodite
In biology, a hermaphrodite is an organism that has reproductive organs normally associated with both male and female sexes.Many taxonomic groups of animals do not have separate sexes. In these groups, hermaphroditism is a normal condition, enabling a form of sexual reproduction in which both...
, meaning that both female and male sexual organs are present in the same individual. The snails produce both eggs
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
and sperm
Sperm
The term sperm is derived from the Greek word sperma and refers to the male reproductive cells. In the types of sexual reproduction known as anisogamy and oogamy, there is a marked difference in the size of the gametes with the smaller one being termed the "male" or sperm cell...
in the ovotestis (also called the hermaphrodite gland), but it is later separated into two divisions, a sperm duct and oviduct
Oviduct
In non-mammalian vertebrates, the passageway from the ovaries to the outside of the body is known as the oviduct. The eggs travel along the oviduct. These eggs will either be fertilized by sperm to become a zygote, or will degenerate in the body...
, respectively.
Mating
Mating
In biology, mating is the pairing of opposite-sex or hermaphroditic organisms for copulation. In social animals, it also includes the raising of their offspring. Copulation is the union of the sex organs of two sexually reproducing animals for insemination and subsequent internal fertilization...
takes several hours, sometimes a day. H. aspersa snails stab a calcite spine, known as a "love dart
Love dart
A love dart is a hard, long, sharp, calcareous or chitinous dart which some hermaphroditic land snails and slugs create. Love darts are made in sexually mature animals only, and are used as part of the sequence of events during courtship, before actual mating takes place...
", at their partner. The love dart is coated with a mucus that contains a chemical that enables more than twice as many sperm to survive inside the recipient. A few days after mating, the eggs are laid in the soil. The eggs are usually 4–6 mm in diameter.
After snails hatch from the egg, they mature in one or more years, depending on where the organism lives. Maturity takes two years in Southern California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
, while it takes only ten months in South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
.
The size of the adult snails slightly varies with species. H. aspersa grows up to 35 mm in height and width, whereas H. pomatia grows up to 45 mm. The life span of snails in the wild is on average two or three years.
Some snails may live longer, perhaps even 30 years or older in the case of the Roman snail but most live less than 8 years. Many deaths are due to predators and parasites.
The garden snail is a relatively fast snail. It has been observed to reach speeds of up to 1.3 cm/s.
Respiration
Since snails in the genus Helix are terrestrial rather than fresh-water or marine, they have developed a simple lung for respiration. (Most other snails and gastropods have gillGill
A gill is a respiratory organ found in many aquatic organisms that extracts dissolved oxygen from water, afterward excreting carbon dioxide. The gills of some species such as hermit crabs have adapted to allow respiration on land provided they are kept moist...
s,instead.)
Oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
is carried by the blood pigment hemocyanin
Hemocyanin
Hemocyanins are respiratory proteins in the form of metalloproteins containing two copper atoms that reversibly bind a single oxygen molecule . Oxygenation causes a color change between the colorless Cu deoxygenated form and the blue Cu oxygenated form...
. Both oxygen and carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
diffuse in and out of blood through the capillaries. A muscular
Muscle
Muscle is a contractile tissue of animals and is derived from the mesodermal layer of embryonic germ cells. Muscle cells contain contractile filaments that move past each other and change the size of the cell. They are classified as skeletal, cardiac, or smooth muscles. Their function is to...
valve regulates the process of opening and closing the entrance of the lung. When the valve opens, the air can either leave or come into the lung. The valve plays an important role in reducing water loss and preventing drowning.
Ecology
Helix snails prefer cool, damp environments, as they easily suffer moisture loss. Snails are most active at night and after rainfall. During unfavourable conditions, a snail will remain inside its shell, usually under rocksRock (geology)
In geology, rock or stone is a naturally occurring solid aggregate of minerals and/or mineraloids.The Earth's outer solid layer, the lithosphere, is made of rock. In general rocks are of three types, namely, igneous, sedimentary, and metamorphic...
or other hiding places, to avoid being discovered by predators. In dry climate
Climate
Climate encompasses the statistics of temperature, humidity, atmospheric pressure, wind, rainfall, atmospheric particle count and other meteorological elemental measurements in a given region over long periods...
s snails will naturally congregate near water sources, including artificial sources such as waste-water outlets of air conditioners.
The common garden snail (Helix aspersa) is herbivorous
Herbivore
Herbivores are organisms that are anatomically and physiologically adapted to eat plant-based foods. Herbivory is a form of consumption in which an organism principally eats autotrophs such as plants, algae and photosynthesizing bacteria. More generally, organisms that feed on autotrophs in...
. These snails are able to digest most vegetation including carrot
Carrot
The carrot is a root vegetable, usually orange in colour, though purple, red, white, and yellow varieties exist. It has a crisp texture when fresh...
s and lettuce
Lettuce
Lettuce is a temperate annual or biennial plant of the daisy family Asteraceae. It is most often grown as a leaf vegetable. It is eaten either raw, notably in salads, sandwiches, hamburgers, tacos, and many other dishes, or cooked, as in Chinese cuisine in which the stem becomes just as important...
. They also have a specialized crop of symbiotic bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
that aid in their digestion, especially with the breakdown of the polysaccharide cellulose
Cellulose
Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to over ten thousand β linked D-glucose units....
into simple sugars.
Many predators, both specialist and generalist, feed on snails. Some animals, such as the song thrush
Song Thrush
The Song Thrush is a thrush that breeds across much of Eurasia. It is also known in English dialects as throstle or mavis. It has brown upperparts and black-spotted cream or buff underparts and has three recognised subspecies...
, break the shell of the snail by hammering it against a hard object, such as stone, in order to expose its edible insides. Other predators, such as some species of frog
Frog
Frogs are amphibians in the order Anura , formerly referred to as Salientia . Most frogs are characterized by a short body, webbed digits , protruding eyes and the absence of a tail...
s, circumvent the need to break snail shells by simply swallowing the snail whole, shell and all.
Some carnivorous species of snails, such as the decollate snail
Decollate snail
The decollate snail, scientific name Rumina decollata, is a medium-sized predatory land snail, a species of terrestrial pulmonate gastropod mollusk in the family Subulinidae.-Distribution:...
and the rosy wolf snail, also prey on Helix snails. Such carnivorous snails are commercially grown and sold in order to combat pest snail species. Many of these also escape into the wild, where they prey on indigenous snails, such as the Cuban land snails of the genus Polymita
Polymita
Polymita, is a genus of large, air-breathing land snails, terrestrial pulmonate gastropod mollusks in the family Helminthoglyptidae.The shell of this species is large, brightly colored, and has numerous color varieties....
, and the indigenous snails of Hawaii
Hawaii
Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...
.
Edible snails
H. pomatia and H. aspersa are the two edible species that are most used in European cuisineCuisine
Cuisine is a characteristic style of cooking practices and traditions, often associated with a specific culture. Cuisines are often named after the geographic areas or regions that they originate from...
. Spanish cuisine also uses Otala punctata
Otala punctata
Otala punctata is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Helicidae. They are prepared in a typical dish in South Spain, "cabrillas", cooked in spicy tomato sauce.-Distribution:...
, Theba pisana
Theba pisana
Theba pisana, common names the white garden snail, the sand hill snail, white Italian snail, the Mediterranean coastal snail, or simply the Mediterranean snail, is an edible species of medium-sized air-breathing land snail, a pulmonate gastropod mollusk in the family Helicidae...
and Iberus gualterianus alonensis, amongst others. The process of snail farming is called heliciculture
Heliciculture
Heliciculture, or snail farming is the process of farming or raising land snails specifically for human consumption, and more recently, to obtain snail slime for cosmetics use....
.
Escargots are often served in a traditional way as appetizers. They may also be used as ingredients in other recipes.
Snails contain many nutrients. They are rich in calcium
Calcium
Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...
and also contain vitamin B1 and E
Vitamin E
Vitamin E is used to refer to a group of fat-soluble compounds that include both tocopherols and tocotrienols. There are many different forms of vitamin E, of which γ-tocopherol is the most common in the North American diet. γ-Tocopherol can be found in corn oil, soybean oil, margarine and dressings...
. They contain various essential amino acid
Amino acid
Amino acids are molecules containing an amine group, a carboxylic acid group and a side-chain that varies between different amino acids. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen...
s, and are low in calorie
Calorie
The calorie is a pre-SI metric unit of energy. It was first defined by Nicolas Clément in 1824 as a unit of heat, entering French and English dictionaries between 1841 and 1867. In most fields its use is archaic, having been replaced by the SI unit of energy, the joule...
s and fat
Fat
Fats consist of a wide group of compounds that are generally soluble in organic solvents and generally insoluble in water. Chemically, fats are triglycerides, triesters of glycerol and any of several fatty acids. Fats may be either solid or liquid at room temperature, depending on their structure...
.