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Wax Esters
A wax ester (WE) is an ester of a fatty acid and a fatty alcohol. Wax esters comprise the main components of three commercially important waxes: carnauba wax, candelilla wax, and beeswax.. Wax esters are formed by combining one fatty acid with one fatty alcohol: :RCOOH + R'OH RCOOR' + H2O Various types of wax esters exist. Some are saturated, and others contain unsaturated centers. Saturated wax esters have higher melting points and are more likely to be solid at room temperature. Unsaturated wax esters have a lower melting point and are more likely to be liquid at room temperature. Both fatty acids and fatty alcohols may be made of different carbon chain length. In the end, there are many different possible combinations of fatty acids and fatty alcohols and each combination will have a unique set of properties in terms of steric orientation and phase transition. The chain lengths of fatty acids and fatty alcohols in naturally occurring wax esters vary. The fatty acids in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sperm Oil
Sperm oil is a waxy liquid obtained from sperm whales. It is a clear, yellowish liquid with a very faint odor. Sperm oil has a different composition from common whale oil, obtained from rendered blubber. Although it is traditionally called an "oil", it is technically a liquid wax. It is composed of wax esters with a small proportion of triglycerides, an ester of an unsaturated fatty acid, and a branched-chain fatty alcohol. ransmission Digest, Volume 26, No. 2, October 2006, "The Science of Synthetic Sperm Whale Oil"/ref> It is a natural antioxidant and heat-transfer agent. In the late-18th and early-19th centuries, sperm oil was prized as an illuminant for its bright, odorless flame and as a lubricant for its low viscosity and stability. It was supplanted in the late 19th century by less expensive alternatives such as kerosene and petroleum-based lubricants. With the 1987 international ban on whaling, sperm oil is no longer legally sold. The oil from bottlenose whales was s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calanus Finmarchicus
''Calanus finmarchicus'' is a species of copepods and a part of zooplankton, which is found in enormous amounts in the northern Atlantic Ocean. Distribution and ecology ''Calanus finmarchicus'' is most commonly found in the North Sea and the Norwegian Sea. It is also found throughout the colder waters of the North Atlantic, especially off the coast of Canada, in the Gulf of Maine, and all the way up to western and northern Svalbard. ''Calanus finmarchicus'' is one of the most commonly found species of zooplankton in the subarctic waters of the North Atlantic. Sometimes confused with '' C. helgolandicus'' and '' C. glacialis'', ''C. finmarchicus'' is a large planktonic copepod whose chief diet includes diatoms, dinoflagellates, and other microplanktonic organisms. In fact, some studies have shown that heterotrophic microplankton provide a "prey resource sufficient for net lipid synthesis as well as egg production". ''C. finmarchicus'' is a key component in the food web of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orange Roughy
The orange roughy (''Hoplostethus atlanticus''), also known as the red roughy, slimehead and deep sea perch, is a relatively large deep-sea fish belonging to the slimehead family (Trachichthyidae). The UK Marine Conservation Society has categorized orange roughy as "vulnerable to exploitation". It is found in , deep (bathypelagic, ) waters of the Western Pacific Ocean, eastern Atlantic Ocean (from Iceland to Morocco; and from Walvis Bay, Namibia, to off Durban, South Africa), Indo-Pacific (off New Zealand and Australia), and in the eastern Pacific off Chile. The orange roughy is notable for its extraordinary lifespan, attaining over 200 years. It is important to commercial deep-trawl fisheries. The fish is a bright, brick-red color, fading to a yellowish-orange after death. Like other slimeheads, orange roughy is slow-growing and late to mature, resulting in a very low resilience, making them extremely susceptible to overfishing. Many stocks (especially those off New Zealand and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Escolar
The escolar, ''Lepidocybium flavobrunneum'', a species of fish in the family Gempylidae, is found in deep (200–885 metres, or 656–2,904 ft) tropical and temperate waters around the world. It is also known as snake mackerel, ' ( Hawaiian, sometimes written '), and is sometimes sold as " butterfish" or " white tuna", a matter aggravated by potential health problems related to consumption of escolar, giving rise to the mocking name ''Ex-Lax fish''. Biology The escolar is dark brown, growing darker with age until it is quite black. It is a fast-swimming fish with a prominent lateral keel and four to six finlets after the anal and second dorsal fins. Escolar can grow to over in length. Like its relative the oilfish (''Ruvettus pretiosus''), escolar cannot metabolize the wax esters (gempylotoxin) naturally found in its diet. This gives the escolar an oil content of 14–25% in its flesh. Health effects The escolar's wax ester content can cause keriorrhea (Greek: f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oilfish
The oilfish (''Ruvettus pretiosus'') is a species of snake mackerel fish with a cosmopolitan distribution in tropical and temperate oceans. It can be found at depths of from , usually between . It can grow to a length of TL (nearly 10 feet) though most do not exceed SL. The maximum recorded weight is . It is currently the only known member of its genus. The flesh of this fish is extremely oily and although edible, the oil actually consists of wax esters, which are not digested like edible oils. The flesh has an oil content of around 25%, and with serving sizes of several ounces and upwards commonplace, some people experience a laxative side effect from such a large amount of wax esters. Some consumers of large amounts of oilfish also experience abdominal cramps and vomiting. Oilfish is pleasantly rich in taste and can be substantially cheaper than some other fish species, leading to some fish sellers intentionally mislabelling it as butterfish or even cod, despite the u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Docosahexaenoic Acid
Docosahexaenoic acid (DHA) is an omega-3 fatty acid that is a primary structural component of the human brain, cerebral cortex, skin, and retina. In physiological literature, it is given the name 22:6(n-3). It can be synthesized from alpha-linolenic acid or obtained directly from maternal milk (breast milk), fatty fish, fish oil, or algae oil. DHA's structure is a carboxylic acid (-''oic acid'') with a 22- carbon chain (''docosa-'' derives from the Ancient Greek for 22) and six (''hexa-'') '' cis'' double bonds (''-en-''); with the first double bond located at the third carbon from the omega end. Its trivial name is cervonic acid (from the Latin word ''cerebrum'' for "brain"), its systematic name is ''all-cis''-docosa-4,7,10,13,16,19-hexa-enoic acid, and its shorthand name is 22:6(n−3) in the nomenclature of fatty acids. Most of the docosahexaenoic acid in fish and multi-cellular organisms with access to cold-water oceanic foods originates from photosynthetic and heterotr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eicosapentaenoic Acid
Eicosapentaenoic acid (EPA; also icosapentaenoic acid) is an omega-3 fatty acid. In physiological literature, it is given the name 20:5(n-3). It also has the trivial name timnodonic acid. In chemical structure, EPA is a carboxylic acid with a 20-carbon chain and five '' cis'' double bonds; the first double bond is located at the third carbon from the omega end. EPA is a polyunsaturated fatty acid (PUFA) that acts as a precursor for prostaglandin-3 (which inhibits platelet aggregation), thromboxane-3, and leukotriene-5 eicosanoids. EPA is both a precursor and the hydrolytic breakdown product of eicosapentaenoyl ethanolamide (EPEA: C22 H35 NO2; 20:5,n-3). Although studies of fish oil supplements, which contain both docosahexaenoic acid (DHA) and EPA, have failed to support claims of preventing heart attacks or strokes, a recent multi-year study of Vascepa ( ethyl eicosapentaenoate, the ethyl ester of the free fatty acid), a prescription drug containing only EPA, was sh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triglyceride
A triglyceride (TG, triacylglycerol, TAG, or triacylglyceride) is an ester derived from glycerol and three fatty acids (from ''wikt:tri-#Prefix, tri-'' and ''glyceride''). Triglycerides are the main constituents of body fat in humans and other vertebrates, as well as vegetable fat. They are also present in the blood to enable the bidirectional transference of Adipose tissue, adipose fat and blood glucose from the liver, and are a major component of sebum, human skin oils. Many types of triglycerides exist. One specific classification focuses on saturated and unsaturated types. Saturated fats have ''no'' C=C groups; unsaturated fats feature one or more C=C groups. Unsaturated fats tend to have a lower melting point than saturated analogues; as a result, they are often liquid at room temperature. Chemical structure Triglycerides are tri-ester In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carboxylesterase
The enzyme carboxylesterase (or carboxylic-ester hydrolase, EC 3.1.1.1; systematic name carboxylic-ester hydrolase) catalyzes reactions of the following form: :a carboxylic ester + H2O \rightleftharpoons an alcohol + a carboxylate Most enzymes from this group are serine hydrolases belonging to the superfamily of proteins with α/β hydrolase fold. Some exceptions include an esterase with β-lactamase-like structure (). Carboxylesterases are widely distributed in nature, and are common in mammalian liver. Many participate in phase I metabolism of xenobiotics such as toxins or drugs; the resulting carboxylates are then conjugated by other enzymes to increase solubility and eventually excreted. The essential polyunsaturated fatty acid arachidonic acid (AA C20 H32 O2; 20: 4, n-6), formed by the synthesis from dietary linoleic acid (LA: C18H32O2 18:2, n-6), has a role as a human carboxylesterase inhibitor. The carboxylesterase family of evolutionarily related proteins (those with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lipase
Lipase ( ) is a family of enzymes that catalyzes the hydrolysis of fats. Some lipases display broad substrate scope including esters of cholesterol, phospholipids, and of lipid-soluble vitamins and sphingomyelinases; however, these are usually treated separately from "conventional" lipases. Unlike esterases, which function in water, lipases "are activated only when adsorbed to an oil–water interface". Lipases perform essential roles in digestion, transport and processing of dietary lipids in most, if not all, organisms. Structure and catalytic mechanism Classically, lipases catalyse the hydrolysis of triglycerides: :triglyceride + H2O → fatty acid + diacylglycerol :diacylglycerol + H2O → fatty acid + monacylglycerol :monacylglycerol + H2O → fatty acid + glycerol Lipases are serine hydrolases, i.e. they function by transesterification generating an acyl serine intermediate. Most lipases act at a specific position on the glycerol backbone of a lipi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Buoyancy
Buoyancy (), or upthrust, is an upward force exerted by a fluid that opposes the weight of a partially or fully immersed object. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus the pressure at the bottom of a column of fluid is greater than at the top of the column. Similarly, the pressure at the bottom of an object submerged in a fluid is greater than at the top of the object. The pressure difference results in a net upward force on the object. The magnitude of the force is proportional to the pressure difference, and (as explained by Archimedes' principle) is equivalent to the weight of the fluid that would otherwise occupy the submerged volume of the object, i.e. the displaced fluid. For this reason, an object whose average density is greater than that of the fluid in which it is submerged tends to sink. If the object is less dense than the liquid, the force can keep the object afloat. This can occur only in a n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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