Oleo Chemistry


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Oleo Chemistry and Oleo Chemicals

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Oleo Chemistry

  1. 1. Oleo ChemistryBadrla Sandeep PDF generated using the open source mwlib toolkit. See http://code.pediapress.com/ for more information. PDF generated at: Sun, 13 May 2012 02:59:59 UTC
  2. 2. ContentsArticles Oleochemistry 1 Oleochemical 1 Fatty acid 2 Fatty alcohol 9 Fatty acid methyl ester 14 Monoglyceride 14 Diglyceride 15 Triglyceride 17 Quaternary ammonium cation 23 Oil 25 Fat 27 Soap 30 Cosmetics 38 Vegetable fats and oils 51 Palm oil 59 Transesterification 71 Hydrogenation 73 Saponification 81References Article Sources and Contributors 85 Image Sources, Licenses and Contributors 89Article Licenses License 91
  3. 3. Oleochemistry 1 Oleochemistry Oleochemistry is the study of vegetable oils and animal oils and fats, and oleochemicals derived from these fats and oils or from petrochemical feedstocks through physico-chemical modifications or transformation. First used in the making of soaps, oleochemistry is now part of our daily lives where it is found in a wide variety of sectors like food, cosmetics, pharmaceutical and industrial. Oleochemical Oleochemicals are chemicals derived from plant and animal fats. They are analogous to petrochemicals derived from petroleum. The formation of basic oleochemical substances like fatty acids, fatty acid methyl esters (FAME), fatty alcohols, fatty amines and glycerols are by various chemical and enzymatic reactions. Intermediate chemical substances produced from these basic oleochemical substances include alcohol ethoxylates, alcohol sulfates, alcohol ether sulfates, quaternary ammonium salts, monoacylglycerols (MAG), diacylglycerols (DAG), structured triacylglycerols (TAG), sugar esters, and other oleochemical products. As the price of crude oil rose in the late 1970s,[1] manufacturers switched from petrochemicals to oleochemicals[2] because plant-based lauric oils processed from palm kernel oil were cheaper. Since then, palm kernel oil is predominantly used in the production of laundry detergent and personal care items like toothpaste, soap bars, shower cream and shampoo.[3] Industry in Asia Southeast Asian countries rapid production growth of palm oil and palm kernel oil in the 1980s spurred the oleochemical industry in Malaysia, Indonesia, and Thailand. Many oleochemical plants were built. Though a nascent and small industry when pitted against big detergent giants in the US and Europe, oleochemical companies in southeast Asia had competitive edge in cheap ingredients.[4] The US fatty chemical industry found it difficult to consistently maintain acceptable levels of profits. Competition was intense with market shares divided among many companies there where neither imports nor exports played a significant role.[5] By the late 1990s, giants like Henkel, Unilever, and Petrofina sold their oleochemical factories to focus on higher profit activities like retail of consumer goods. Since the Europe outbreak of mad cow disease or (bovine spongiform encephalopathy) in 2000, tallow is replaced for many uses by vegetable oleic fatty acids, such as palm kernel and coconut oils.[6] Applications The most common application of oleochemicals is biodiesel production. Fatty acids are esterified with an alcohol, commonly methanol to form methyl esters. Another common application is in the production of detergents. Lauric acid is used to produce sodium lauryl sulfate, the main ingredient in many personal care products. Other applications include the production of lubricants, green solvents, and bioplastics. Hydrolysis The fat splitting (or hydrolysis) of the triglycerides produces fatty acids and glycerol: RCOOCH2–CHOOCR–CH2OCOR + 3 H2O → 3 RCOOH + HOCH2–CHOH–CH2OH The addition of base helps the reaction proceed more quickly.
  4. 4. Oleochemical 2 Transesterification If oils or fats are made to react with an alcohol (ROH) instead of with water, the process is alcoholysis. It is also called transesterification, because the glycerol fragment of the fatty acid tri-ester is exchanged for that of another alcohol. Thus, the products are fatty acid esters and glycerol: RCOOCH2–CHOOCR–CH2OCOR + 3 ROH → 3 RCOOR + HOCH2–CHOH–CH2OH The fatty acid or fatty esters produced by these methods may be transformed. For example, hydrogenation converts unsaturated fatty acids into saturated fatty acids. The acids or esters can also be reduced to give fatty alcohols. References [1] Haupt, D. E.; Drinkard, G.; Pierce, H. F. (1984). "Future of petrochemical raw materials in oleochemical markets". Journal of the American Oil Chemists Society 61 (2): 276. doi:10.1007/BF02678781. [2] Akaike, Yoshiteru (1985). "Other oleochemical uses: Palm oil products". Journal of the American Oil Chemists Society 62 (2): 335. doi:10.1007/BF02541401. [3] Dewaet, F. (1985). "Quality requirements from a consumer’s point of view (oleochemical products)". Journal of the American Oil Chemists Society 62 (2): 366. doi:10.1007/BF02541406. [4] The future of palm oil in oleochemicals (http:/ / palmoilis. mpob. gov. my/ publications/ pod14-3. pdf) Appalasami & de Vries, Palm Oil Developments 14-3, 1990 [5] Leonard, E. Charles; Kapald, S L (1984). "Challenges to a mature industry: Marketing and economics of oleochemicals in the United States". Journal of the American Oil Chemists Society 61 (2): 176. doi:10.1007/BF02678763. [6] The Changing World of Oleochemicals (http:/ / palmoilis. mpob. gov. my/ publications/ pod44-wolfgang. pdf) Wolfgang Rupilius and Salmiah Ahmad, Palm Oil Developments 44, 2005 Fatty acid In chemistry, especially biochemistry, a fatty acid is a carboxylic acid with a long aliphatic tail (chain), which is either saturated or unsaturated. Most naturally occurring fatty acids have a chain of an even number of carbon atoms, from 4 to 28.[1] Fatty acids are usually derived from triglycerides or phospholipids. When they are not attached to other molecules, they are known as "free" fatty acids. Fatty acids are important sources of fuel because, when metabolized, they Butyric acid, a short-chain fatty acid yield large quantities of ATP. Many cell types can use either glucose or fatty acids for this purpose. In particular, heart and skeletal muscle prefer fatty acids. The brain cannot use fatty acids as a source of fuel; it relies on glucose or ketone bodies.[2]
  5. 5. Fatty acid 3 Types of fatty acids Fatty acids that have double bonds are known as unsaturated. Fatty acids without double bonds are known as saturated. They differ in length as well. Length of free fatty acid chains Fatty acid chains differ by length, often categorized as short, medium, or long. • Short-chain fatty acids (SCFA) are fatty acids with aliphatic tails of fewer than six carbons (i.e. butyric acid). • Medium-chain fatty acid (MCFA) are fatty acids with aliphatic tails of 6–12[3] carbons, which can form medium-chain Three dimensional representations of several fatty acids triglycerides. • Long-chain fatty acid (LCFA) are fatty acids with aliphatic tails longer than 12 carbons.[4] • Very long chain fatty acid (VLCFA) are fatty acids with aliphatic tails longer than 22 carbons Unsaturated fatty acids Unsaturated fatty acids have one or more double bonds between carbon atoms. (Pairs of carbon atoms connected by double bonds can be saturated by adding hydrogen atoms to them, converting the double bonds to single bonds. Therefore, the double bonds are called unsaturated.) The two carbon atoms in the chain that are bound next to either side of the double bond can occur in a cis or trans configuration. cis A cis configuration means that adjacent hydrogen atoms are on the same side of the double bond. The rigidity of the double bond freezes its Comparison of the trans isomer (top) Elaidic acid and the cis-isomer oleic acid. conformation and, in the case of the cis isomer, causes the chain to bend and restricts the conformational freedom of the fatty acid. The more double bonds the chain has in the cis configuration, the less flexibility it has. When a chain has many cis bonds, it becomes quite curved in its most accessible conformations. For example, oleic acid, with one double bond, has a "kink" in it, whereas linoleic acid, with two double bonds, has a more pronounced bend. Alpha-linolenic acid, with three double bonds, favors a hooked shape. The effect of this is that, in restricted environments, such as when fatty acids are part of a phospholipid in a lipid bilayer, or triglycerides in lipid droplets, cis bonds limit the ability of fatty acids to be closely packed, and therefore could affect the melting temperature of the membrane or of the fat.
  6. 6. Fatty acid 4 trans A trans configuration, by contrast, means that the next two hydrogen atoms are bound to opposite sides of the double bond. As a result, they do not cause the chain to bend much, and their shape is similar to straight saturated fatty acids. In most naturally occurring unsaturated fatty acids, each double bond has three n carbon atoms after it, for some n, and all are cis bonds. Most fatty acids in the trans configuration (trans fats) are not found in nature and are the result of human processing (e.g., hydrogenation). The differences in geometry between the various types of unsaturated fatty acids, as well as between saturated and unsaturated fatty acids, play an important role in biological processes, and in the construction of biological structures (such as cell membranes). Examples of Unsaturated Fatty Acids Common Chemical structure Δx C:D n−x nameMyristoleic CH3(CH2)3CH=CH(CH2)7COOH cis-Δ9 14:1 n−5acidPalmitoleic CH3(CH2)5CH=CH(CH2)7COOH cis-Δ9 16:1 n−7acidSapienic acid CH3(CH2)8CH=CH(CH2)4COOH cis-Δ6 16:1 n−10Oleic acid CH3(CH2)7CH=CH(CH2)7COOH cis-Δ9 18:1 n−9Elaidic acid CH3(CH2)7CH=CH(CH2)7COOH trans-Δ9 18:1 n−9Vaccenic acid CH3(CH2)5CH=CH(CH2)9COOH trans-Δ11 18:1 n−7Linoleic acid CH3(CH2)4CH=CHCH2CH=CH(CH2)7COOH cis,cis-Δ9,Δ12 18:2 n−6Linoelaidic CH3(CH2)4CH=CHCH2CH=CH(CH2)7COOH trans,trans-Δ9,Δ12 18:2 n−6acidα-Linolenic CH3CH2CH=CHCH2CH=CHCH2CH=CH(CH2)7COOH cis,cis,cis-Δ9,Δ12,Δ15 18:3 n−3acidArachidonic [5] 20:4 n−6 CH (CH ) CH=CHCH CH=CHCH CH=CHCH CH=CH(CH ) COOH NIST cis,cis,cis,cis-Δ5Δ8,Δ11,Δ14 3 2 4 2 2 2 2 3acidEicosapentaenoicCH CH CH=CHCH CH=CHCH CH=CHCH CH=CHCH CH=CH(CH ) COOH cis,cis,cis,cis,cis-Δ5,Δ8,Δ11,Δ14,Δ17 20:5 n−3 3 2 2 2 2 2 2 3acidErucic acid CH (CH ) CH=CH(CH ) COOH cis-Δ13 22:1 n−9 3 2 7 2 11DocosahexaenoicCH CH CH=CHCH CH=CHCH CH=CHCH CH=CHCH CH=CHCH CH=CH(CH ) COOH cis,cis,cis,cis,cis,cis-Δ4,Δ7,Δ10,Δ13,Δ16,Δ19 22:6 n−3 3 2 2 2 2 2 2 2 2acid Essential fatty acids Fatty acids that are required by the human body but cannot be made in sufficient quantity from other substrates, and therefore must be obtained from food, are called essential fatty acids. There are two series of essential fatty acids: one has a double bond three carbon atoms removed from the methyl end; the other has a double bond six carbon atoms removed from the methyl end. Humans lack the ability to introduce double bonds in fatty acids beyond carbons 9 and 10, as counted from the carboxylic acid side.[6] Two essential fatty acids are linoleic acid (LA) and alpha-linolenic acid (ALA). They are widely distributed in plant oils. The human body has a limited ability to convert ALA into the longer-chain n-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA),
  7. 7. Fatty acid 5 which can also be obtained from fish. Saturated fatty acids Saturated fatty acids are long-chain carboxylic acids that usually have between 12 and 24 carbon atoms and have no double bonds. Thus, saturated fatty acids are saturated with hydrogen (since double bonds reduce the number of hydrogens on each carbon). Because saturated fatty acids have only single bonds, each carbon atom within the chain has 2 hydrogen atoms (except for the omega carbon at the end that has 3 hydrogens). Examples of Saturated Fatty Acids Common name Chemical structure C:D Caprylic acid CH3(CH2)6COOH 8:0 Capric acid CH3(CH2)8COOH 10:0 Lauric acid CH3(CH2)10COOH 12:0 Myristic acid CH3(CH2)12COOH 14:0 Palmitic acid CH3(CH2)14COOH 16:0 Stearic acid CH3(CH2)16COOH 18:0 Arachidic acid CH3(CH2)18COOH 20:0 Behenic acid CH3(CH2)20COOH 22:0 Lignoceric acid CH3(CH2)22COOH 24:0 Cerotic acid CH3(CH2)24COOH 26:0 Nomenclature Several different systems of nomenclature are used for fatty acids. The following table describes the most common systems. Numbering of carbon atoms System Example Explanation Trivial Palmitoleic acid Trivial names (or common names) are non-systematic historical names, which are the most nomenclature frequent naming system used in literature. Most common fatty acids have trivial names in addition to their systematic names (see below). These names frequently do not follow any pattern, but they are concise and often unambiguous. Systematic (9Z)-octadecenoic acid Systematic names (or IUPAC names) derive from the standard IUPAC Rules for the Nomenclature nomenclature [7] of Organic Chemistry, published in 1979, along with a recommendation published specifically for [8] lipids in 1977. Counting begins from the carboxylic acid end. Double bonds are labelled with cis-/trans- notation or E-/Z- notation, where appropriate. This notation is generally more verbose than common nomenclature, but has the advantage of being more technically clear and descriptive. Δx cis,cis-Δ9,Δ12 In Δx (or delta-x) nomenclature, each double bond is indicated by Δx, where the double bond is nomenclature octadecadienoic acid located on the xth carbon–carbon bond, counting from the carboxylic acid end. Each double bond is preceded by a cis- or trans- prefix, indicating the conformation of the molecule around the bond. For example, linoleic acid is designated "cis-Δ9, cis-Δ12 octadecadienoic acid". This nomenclature has the advantage of being less verbose than systematic nomenclature, but is no more technically clear or descriptive.
  8. 8. Fatty acid 6 n−x n−3 n−x (n minus x; also ω−x or omega-x) nomenclature both provides names for individual nomenclature compounds and classifies them by their likely biosynthetic properties in animals. A double bond is located on the xth carbon–carbon bond, counting from the terminal methyl carbon (designated as n or ω) toward the carbonyl carbon. For example, α-Linolenic acid is classified as a n−3 or omega-3 fatty acid, and so it is likely to share a biosynthetic pathway with other compounds of this type. The ω−x, omega-x, or "omega" notation is common in popular nutritional literature, but IUPAC has [7] deprecated it in favor of n−x notation in technical documents. The most commonly researched fatty acid biosynthetic pathways are n−3 and n−6, which are hypothesized to decrease or increase, respectively, inflammation. Lipid numbers 18:3 Lipid numbers take the form C:D, where C is the number of carbon atoms in the fatty acid and D is 18:3, n−6 the number of double bonds in the fatty acid. This notation can be ambiguous, as some different 18:3, cis,cis,cis-Δ9,Δ12,Δ15 fatty acids can have the same numbers. Consequently, when ambiguity exists this notation is usually [7] paired with either a Δx or n−x term. Production Fatty acids are usually produced industrially by the hydrolysis of triglycerides, with the removal of glycerol (see oleochemicals). Phospholipids represent another source. Some fatty acids are produced synthetically by hydrocarboxylation of alkenes. Free fatty acids The biosynthesis of fatty acids involves the condensation of acetyl-CoA. Since this coenzyme carries a two-carbon-atom group, almost all natural fatty acids have even numbers of carbon atoms. The "uncombined fatty acids" or "free fatty acids" found in organisms come from the breakdown of a triglyceride. Because they are insoluble in water, these fatty acids are transported (solubilized, circulated) while bound to plasma protein albumin. The levels of "free fatty acid" in the blood are limited by the availability of albumin binding sites. Fatty acids in dietary fats The following table gives the fatty acid, vitamin E and cholesterol composition of some common dietary fats.[9] [10] Saturated Monounsaturated Polyunsaturated Cholesterol Vitamin E g/100g g/100g g/100g mg/100g mg/100g Animal fats Lard 40.8 43.8 9.6 93 0.00 [11] 33.2 49.3 12.9 100 2.70 Duck fat Butter 54.0 19.8 2.6 230 2.00 Vegetable fats Coconut oil 85.2 6.6 1.7 0 .66 Palm oil 45.3 41.6 8.3 0 33.12 Cottonseed oil 25.5 21.3 48.1 0 42.77 Wheat germ oil 18.8 15.9 60.7 0 136.65 Soya oil 14.5 23.2 56.5 0 16.29 Olive oil 14.0 69.7 11.2 0 5.10 Corn oil 12.7 24.7 57.8 0 17.24 Sunflower oil 11.9 20.2 63.0 0 49.0
  9. 9. Fatty acid 7 Safflower oil 10.2 12.6 72.1 0 40.68 Hemp oil 10 15 75 0 Canola/Rapeseed oil 5.3 64.3 24.8 0 22.21 Reactions of fatty acids Fatty acids exhibit reactions like other carboxylic acid, i.e. they undergo esterification and acid-base reactions. Acidity Fatty acids do not show a great variation in their acidities, as indicated by their respective pKa. Nonanoic acid, for example, has a pKa of 4.96, being only slightly weaker than acetic acid (4.76). As the chain length increases the solubility of the fatty acids in water decreases very rapidly, so that the longer-chain fatty acids have minimal effect on the pH of an aqueous solution. Even those fatty acids that are insoluble in water will dissolve in warm ethanol, and can be titrated with sodium hydroxide solution using phenolphthalein as an indicator to a pale-pink endpoint. This analysis is used to determine the free fatty acid content of fats; i.e., the proportion of the triglycerides that have been hydrolyzed. Hydrogenation and hardening Hydrogenation of unsaturated fatty acids is widely practiced to give saturated fatty acids, which are less prone toward rancidification. Since the saturated fatty acids are higher melting than the unsaturated relatives, the process is called hardening. This technology is used to convert vegetable oils into margarine. During partial hydrogenation, unsaturated fatty acids can be isomerized from cis to trans configuration.[12] More forcing hydrogenation, i.e. using higher pressures of H2 and higher temperatures, converts fatty acids into fatty alcohols. Fatty alcohols are, however, more easily produced from fatty acid esters. In the Varrentrapp reaction certain unsaturated fatty acids are cleaved in molten alkali, a reaction at one time of relevance to structure elucidation. Auto-oxidation and rancidity Unsaturated fatty acids undergo a chemical change known as auto-oxidation. The process requires oxygen (air) and is accelerated by the presence of trace metals. Vegetable oils resists this process because they contain antioxidants, such as tocopherol. Fats and oils often are treated with chelating agents such as citric acid to remove the metal catalysts. Ozonolysis Unsaturated fatty acids are susceptible to degradation by ozone. This reaction is practiced in the production of azelaic acid ((CH2)7(CO2H)2) from oleic acid.[12] Circulation Digestion and intake Short- and medium-chain fatty acids are absorbed directly into the blood via intestine capillaries and travel through the portal vein just as other absorbed nutrients do. However, long-chain fatty acids are not directly released into the intestinal capillaries. Instead they are absorbed into the fatty walls of the intestine villi and reassembled again into triglycerides. The triglycerides are coated with cholesterol and protein (protein coat) into a compound called a chylomicron.
  10. 10. Fatty acid 8 Within the villi, the chylomicron enters a lymphatic capillary called a lacteal, which merges into larger lymphatic vessels. It is transported via the lymphatic system and the thoracic duct up to a location near the heart (where the arteries and veins are larger). The thoracic duct empties the chylomicrons into the bloodstream via the left subclavian vein. At this point the chylomicrons can transport the triglycerides to tissues where they are stored or metabolized for energy. Metabolism Fatty acids (provided either by ingestion or by drawing on triglycerides stored in fatty tissues) are distributed to cells to serve as a fuel for muscular contraction and general metabolism. They are consumed by mitochondria to produce ATP through beta oxidation. Distribution Blood fatty acids are in different forms in different stages in the blood circulation. They are taken in through the intestine in chylomicrons, but also exist in very low density lipoproteins (VLDL) and low density lipoproteins (LDL) after processing in the liver. In addition, when released from adipocytes, fatty acids exist in the blood as free fatty acids. It is proposed that the blend of fatty acids exuded by mammalian skin, together with lactic acid and pyruvic acid, is distinctive and enables animals with a keen sense of smell to differentiate individuals.[13] References [1] IUPAC Compendium of Chemical Terminology (http:/ / goldbook. iupac. org/ F02330. html) (2nd ed.). International Union of Pure and Applied Chemistry. 1997. ISBN 0-521-51150-X. . Retrieved 2007-10-31. [2] Mary K. Campbell, Shawn O. Farrell (2006). Biochemistry (5th ed.). Cengage Learning. p. 579. ISBN 0-534-40521-5. [3] Medscape: Free CME, Medical News, Full-text Journal Articles & More (http:/ / emedicine. medscape. com/ article/ 946755-overview) [4] Christopher Beermann1, J Jelinek1, T Reinecker2, A Hauenschild2, G Boehm1, and H-U Klör2, " Short term effects of dietary medium-chain fatty acids and n-3 long-chain polyunsaturated fatty acids on the fat metabolism of healthy volunteers (http:/ / lipidworld. com/ content/ 2/ 1/ 10)" [5] http:/ / webbook. nist. gov/ cgi/ cbook. cgi?Name=Arachidonic+ Acid& Units=SI [6] Cell Biology: A Short Course (http:/ / books. google. com/ books?id=3a6p9pA5gZ8C& pg=PA42) [7] Rigaudy, J.; Klesney, S.P. (1979). Nomenclature of Organic Chemistry. Pergamon. ISBN 0-08-022369-9. OCLC 5008199. [8] "The Nomenclature of Lipids. Recommendations, 1976" (http:/ / www. blackwell-synergy. com/ doi/ pdf/ 10. 1111/ j. 1432-1033. 1977. tb11778. x). European Journal of Biochemistry 79 (1): 11–21. 1977. doi:10.1111/j.1432-1033.1977.tb11778.x. . [9] Food Standards Agency (1991). "Fats and Oils". McCance & Widdowsons the Composition of Foods. Royal Society of Chemistry. [10] Ted Altar. "More Than You Wanted To Know About Fats/Oils" (http:/ / www. efn. org/ ~sundance/ fats_and_oils. html). Sundance Natural Foods Online. . Retrieved 2006-08-31. [11] U. S. Department of Agriculture.. "USDA National Nutrient Database for Standard Reference" (http:/ / www. nal. usda. gov/ fnic/ foodcomp/ search/ ). U. S. Department of Agriculture.. . Retrieved 2010-02-17. [12] David J. Anneken, Sabine Both, Ralf Christoph, Georg Fieg, Udo Steinberner, Alfred Westfechtel "Fatty Acids" in Ullmanns Encyclopedia of Industrial Chemistry 2006, Wiley-VCH, Weinheim. doi:10.1002/14356007.a10_245.pub2 [13] "Electronic Nose Created To Detect Skin Vapors" (http:/ / www. sciencedaily. com/ releases/ 2009/ 07/ 090721091839. htm). Science Daily. July 21, 2009. . Retrieved 2010-05-18.
  11. 11. Fatty acid 9 External links • Lipid Library (http://www.lipidlibrary.co.uk/) • Prostaglandins, Leukotrienes & Essential Fatty Acids Journal (http://intl.elsevierhealth.com/journals/plef/) • Fatty Blood Acids (http://www.dmfpolska.eu/Diagnostics.html) Fatty alcohol Fatty alcohols are aliphatic alcohols consisting of a chain of 8 to 22 carbon atoms. Fatty alcohols usually have even number of carbon atoms and a single alcohol group (-OH) attached to the terminal carbon. Some are unsaturated and some are branched. They are widely used in industrial chemistry. Production and occurrence Fatty alcohol Most fatty alcohols in nature are found as waxes which are esters with fatty acids and fatty alcohols.[1] They are produced by bacteria, plants and animals for purposes of buoyancy, as source of metabolic water and energy, biosonoar lenses (marine mammals) and for thermal insulation in the form of waxes (in plants and insects).[2] Fatty alcohols were unavailable until the early 1900s. They were originally obtained by reduction of wax esters with sodium by the Bouveault–Blanc reduction process. In the 1930s catalytic hydrogenation was commercialized, which allowed the conversion of fatty acid esters, typically tallow, to the alcohols. In the 1940s and 1950s, petrochemicals became an important source of chemicals, and Karl Ziegler had discovered the polymerization of ethylene. These two developments opened the way to synthetic fatty alcohols. From natural sources The traditional and still important source of fatty alcohols are fatty acid esters. Wax esters were formerly extracted from sperm oil, obtained from whales. An alternative plant source is jojoba. Fatty acid triesters, known as triglycerides, are obtained from plant and animal sources. These triesters are subjected to transesterification to give methyl esters, which in turn are hydrogenated to the alcohols. Although tallow is typically C16-C18, the chain length from plant sources are more variable. Higher alcohols (C20–C22) can be obtained from rapeseed. Shorter alcohols (C12-C14) are obtained from coconut oil. From petrochemical sources Fatty alcohols are also prepared from petrochemical sources. In the Ziegler process, ethylene is oligomerized using triethylaluminium followed by air oxidation. This process affords even-numbered alcohols: Al(C2H5)3 + 18 C2H4 → Al(C14H29)3 Al(C14H29)3 + 1.5 O2 + 1.5 H2O → 3 HOC14H29 + 0.5 Al2O3 Alternatively ethylene can be oligomerized to give mixtures of alkenes, which are subjected to hydroformylation, this process affording odd-numbered aldehyde, which is subsequently hydrogenated. For example, from 1-decene, hydroformylation gives the C11 alcohol: C8H17CH=CH2 + H2 + CO → C8H17CH2CH2CHO C8H17CH2CH2CHO + H2 → C8H17CH2CH2CH2OH In the Shell higher olefin process, the chain-length distribution in the initial mixture of alkene oligomers is adjusted so as to more closely match market demand. Shell does this by means of an intermediate metathesis reaction.[3] The
  12. 12. Fatty alcohol 10 resultant mixture is fractionated and hydroformylated/hydrogenated in a subsequent step. Applications Fatty alcohols are mainly used in the production of detergents and surfactants. They are components also of cosmetics, foods, and as industrial solvents. Due to their amphipathic nature, fatty alcohols behave as nonionic surfactants. They find use as emulsifiers, emollients and thickeners in cosmetics and food industry. Nutrition Very long chain fatty alcohols (VLCFA), obtained from plant waxes and beeswax have been reported to lower plasma cholesterol in humans. They can be found in unrefined cereal grains, beeswax, and many plant-derived foods. Reports suggest that 5–20 mg per day of mixed C24–C34 alcohols, including octacosanol and triacontanol, lower low-density lipoprotein (LDL) cholesterol by 21%–29% and raise high-density lipoprotein cholesterol by 8%–15%. Wax esters are hydrolyzed by a bile salt–dependent pancreatic carboxyl esterase, releasing long chain alcohols and fatty acids that are absorbed in the gastrointestinal tract. Studies of fatty alcohol metabolism in fibroblasts suggest that very long chain fatty alcohols, fatty aldehydes, and fatty acids are reversibly inter-converted in a fatty alcohol cycle. The metabolism of these compounds is impaired in several inherited human peroxisomal disorders, including adrenoleukodystrophy and Sjögren-Larsson syndrome.[4] Safety Exposure Exposure could occur with commercial application in the manufacturing (such as in production and formulation) or with use of the final product. Hazards are mitigated in industry by following information found in material safety data sheets. Human Health Tests of acute and repeated exposures have revealed a low level of toxicity from inhalation, oral or dermal exposure of fatty alcohols. Fatty alcohols are not very volatile and the acute lethal concentration is greater than the saturated vapor pressure. Longer chain (C12-C16) fatty alcohols produce less health effects than short chain (< C12). Short chain fatty alcohols are considered eye irritants, while long chain alcohols are not.[5] There is no skin sensitization potential from fatty alcohols.[6] Repeated exposure to fatty alcohols produce low level toxicity and certain compounds in this category can cause local irritation on contact or low-grade liver effects (essentially linear alcohols have a slightly higher rate of occurrence of these effects). No effects on the central nervous system have been seen with inhalation and oral exposure. Tests of repeated bolus dosages of 1-hexanol and 1-octanol showed potential for CNS depression and induced respiratory distress. No potential for peripheral neuropathy has been found. In rats, the no observable adverse effect level (NOAEL) ranges from 200 mg/kg/day to 1000 mg/kg/day by ingestion. There has been no evidence that fatty alcohols are carcinogenic, mutagenic, or cause reproductive toxicity or infertility.Fatty alcohols are effectively eliminated from the body when exposed, limiting possibility of retention or bioaccumulation.[] Margins of exposure resulting from consumer uses of these chemicals are adequate for the protection of human health as determined by the Organization for Economic Co-operation and Development (OECD) high production volume chemicals program.[5][7]
  13. 13. Fatty alcohol 11 Environment Fatty alcohols up to chain length C18 are biodegradable, with length up to C16 biodegrading within 10 days completely. Chains C16 to C18 were found to biodegrade from 62% to 76% in 10 days. Chains greater than C18 were found to degrade by 37% in 10 days. Field studies at waste-water treatment plants have shown that 99% of fatty alcohols lengths C12-C18 are removed.[] Fate prediction using Fugacity modeling has shown that fatty alcohols with chain lengths of C10 and greater in water partition into sediment. Lengths C14 and above are predicted to stay in the air upon release. Modeling shows that each type of fatty alcohol will respond independently upon environmental release.[] Aquatic Organisms Fish, invertebrates and algae experience similar levels of toxicity with fatty alcohols although it is dependent on chain length with the shorter chain having greater toxicity potential. Longer chain lengths show no toxicity to aquatic organisms.[] Chain Size Acute Toxicity Chronic Toxicity < C11 1–100 mg/l 0.1-1.0 mg/l C11-C13 0.1-1.0 mg/l 0.1 - <1.0 mg/l C14-C15 NA 0.01 mg/l >C16 NA NA This category of chemicals was evaluated under the Organization for Economic Co-operation and Development (OECD) high production volume chemicals program. No unacceptable environmental risks were identified.[7] Common names and related compounds Name Carbon atoms Branches/saturated? Formula capryl alcohol (1-octanol) 8 carbon atoms 2-ethyl hexanol 8 carbon atoms branched pelargonic alcohol (1-nonanol) 9 carbon atoms capric alcohol (1-decanol, decyl alcohol) 10 carbon atoms Undecyl alcohol (1-undecanol, undecanol, 11 carbon Hendecanol) atoms Lauryl alcohol (Dodecanol, 1-dodecanol) 12 carbon atoms Tridecyl alcohol (1-tridecanol, tridecanol, 13 carbon isotridecanol) atoms Myristyl alcohol (1-tetradecanol) 14 carbon atoms Pentadecyl alcohol (1-pentadecanol, pentadecanol) 15 carbon atoms cetyl alcohol (1-hexadecanol) 16 carbon atoms palmitoleyl alcohol (cis-9-hexadecen-1-ol) 16 carbon unsaturated CH3(CH2)5CH=CH(CH2)8OH atoms
  14. 14. Fatty alcohol 12 Heptadecyl alcohol (1-n-heptadecanol, heptadecanol) 17 carbon atoms stearyl alcohol (1-octadecanol) 18 carbon atoms isostearyl alcohol (16-methylheptadecan-1-ol) 18 carbon branched (CH3)2CH-(CH2)15OH atoms elaidyl alcohol (9E-octadecen-1-ol) 18 carbon unsaturated CH3(CH2)7CH=CH(CH2)8OH atoms oleyl alcohol (cis-9-octadecen-1-ol) 18 carbon unsaturated atoms linoleyl alcohol (9Z, 12Z-octadecadien-1-ol) 18 carbon polyunsaturated, atoms a hydrolyzation of linoleic acid, an omega 6 fatty acid elaidolinoleyl alcohol (9E, 12E-octadecadien-1-ol) 18 carbon polyunsaturated atoms linolenyl alcohol (9Z, 12Z, 15Z-octadecatrien-1-ol) 18 carbon polyunsaturated atoms elaidolinolenyl alcohol (9E, 12E, 18 carbon polyunsaturated 15-E-octadecatrien-1-ol) atoms ricinoleyl alcohol (12-hydroxy-9-octadecen-1-ol) 18 carbon unsaturated, diol CH3(CH2)5CH(OH)CH2CH=CH(CH2)8OH atoms Nonadecyl alcohol (1-nonadecanol) 19 carbon atoms arachidyl alcohol (1-eicosanol) 20 carbon atoms Heneicosyl alcohol (1-heneicosanol) 21 carbon atoms behenyl alcohol (1-docosanol) 22 carbon atoms erucyl alcohol (cis-13-docosen-1-ol) 22 carbon unsaturated CH3(CH2)7CH=CH(CH2)12OH atoms lignoceryl alcohol (1-tetracosanol) 24 carbon atoms ceryl alcohol (1-hexacosanol) 26 carbon atoms 1-heptacosanol 27 carbon atoms montanyl alcohol, cluytyl alcohol (1-octacosanol) 28 carbon atoms 1-nonacosanol 29 carbon atoms myricyl alcohol, melissyl alcohol (1-triacontanol) 30 carbon atoms 1-dotriacontanol 32 carbon atoms geddyl alcohol (1-tetratriacontanol) 34 carbon atoms
  15. 15. Fatty alcohol 13 Cetearyl alcohol Behenyl alcohol, lignoceryl alcohol, ceryl alcohol, 1-heptacosanol, montanyl alcohol, 1-nonacosanol, myricyl alcohol, 1-dotriacontanol, and geddyl alcohol are together classified as policosanol, with montanyl alcohol and myricyl alcohol being the most abundant. References [1] Klaus Noweck, Wolfgang Grafahrend, "Fatty Alcohols" in Ullmann’s Encyclopedia of Industrial Chemistry 2006, Wiley-VCH, Weinheim. [2] Stephen Mudge; Wolfram Meier-Augenstein, Charles Eadsforth and Paul DeLeo (2010). "What contribution do detergent fatty alcohols make to sewage discharges and the maine environment?". Journal of Environmental Monitoring: 1846–1856. doi:10.1039/C0EM00079E. [3] Ashfords Dictionary of Industrial Chemicals, Third edition, 2011, page 6706-6711 [4] Nutritional Significance and Metabolism of Very Long Chain Fatty Alcohols and Acids from Dietary Waxes - Hargrove et al. 229 (3): 215 - Experimental Biology and Medicine (http:/ / www. ebmonline. org/ cgi/ content/ abstract/ 229/ 3/ 215) [5] Veenstra, Gauke; Catherine Webb, Hans Sanderson, Scott E. Belanger, Peter Fisk, Allen Nielson, Yutaka Kasai, Andreas Willing, Scott Dyer, David Penney, Hans Certa, Kathleen Stanton, Richard Sedlak (2009). "Human health risk assessment of long chain alcohols". Ecotoxicology and Environmental Safety: 1016–1030. doi:10.1016/j.ecoenv.2008.07.012. [6] UK/ICCA (2006). "SIDS Initial Assessment Profile" (http:/ / webnet. oecd. org/ hpv/ UI/ handler. axd?id=03441f78-d135-4cab-b832-edfb1d0d677e). OECD Existing Chemicals Database. . [7] Sanderson, Hans; Scott E. Belanger, Peter R. Fisk, Christoph Schäfers, Gauke Veenstra, Allen M. Nielsen, Yutaka Kasai, Andreas Willing, Scott D. Dyer, Kathleen Stanton, Richard Sedlak, (May 2009). "An overview of hazard and risk assessment of the OECD high production volume chemical category—Long chain alcohols [C6–C22] (LCOH)". Ecotoxicology and Environmental Safety 72 (4): 973–979. doi:10.1016/j.ecoenv.2008.10.006. External links • Cyberlipid. "Fatty Alcohols and Aldehydes" (http://www.cyberlipid.org/simple/simp0003.htm). Retrieved 2007-02-06. General overview of fatty alcohols, with references. • CONDEA. "Dr. Z Presents All about fatty alcohols" (http://www.zenitech.com/documents/new pdfs/articles/ All about fatty alcohols Condea.pdf). Retrieved 2007-02-06.
  16. 16. Fatty acid methyl ester 14 Fatty acid methyl ester Fatty acid methyl esters (FAME) are a type of fatty acid ester than can be produced by an alkali-catalyzed reaction between fats or fatty acids and methanol. The molecules in biodiesel are primarily FAMEs, usually obtained from vegetable oils by transesterification. Since every microorganism has its specific FAME profile (microbial fingerprinting), it can be used as a tool for microbial source tracking (MST). The types and proportions of fatty acids present in cytoplasm membrane and outer membrance (gram negative) lipids of cells are major phenotypic trains. Clinical analysis can determine the lengths, bonds, rings and branches of the FAME. To perform this analysis, a bacterial culture is taken, and the fatty acids extracted and used to form methyl esters. The volatile derivatives are then introduced into a gas chromatagraph, and the patterns of the peaks help identify the organism. This is widely used in characterizing new species of bacteria, and is useful for identifying pathogenic strains. Monoglyceride A monoglyceride, more correctly known as a monoacylglycerol, is a glyceride consisting of one fatty acid chain covalently bonded to a glycerol molecule through an ester linkage.[1] Monoacylglycerol can be broadly divided into two groups; 1-monoacylglycerols and 2-monoacylglycerols, depending on the position of General chemical structure of a the ester bond on the glycerol moiety. 1-monoacylglycerol Monoacylglycerols can be formed by both industrial chemical and biological processes. They are formed biochemically via release of a fatty acid from diacylglycerol by diacylglycerol lipase. Monoacylglycerols are broken down by monoacylglycerol lipase. Mono- and diglycerides are commonly added to commercial food products in small quantities. They act as emulsifiers, helping to mix ingredients such as oil and water that would not otherwise blend well.[2] The commercial source may be either animal (cow- or hog-derived) or vegetable, and they may be synthetically made as well. They are often found General chemical structure of a 2-monoacylglycerol in bakery products, beverages, ice cream, chewing gum, shortening, whipped toppings, margarine, and confections. When used in bakery products, monoglycerides improve loaf volume, and create a smooth, soft crumb. One special monoacylglycerol, 2-arachidonoylglycerol, is a full agonist of the cannabinoid receptors. Another important monoacylglycerol is 2-oleoylglycerol, which is a GPR119 agonist.[3]
  17. 17. Monoglyceride 15 References [1] "Monoacylglycerols" (http:/ / www. cyberlipid. org/ glycer/ glyc0002. htm). Cyberlipid Center. . [2] "Questions About Food Ingredients" (http:/ / www. vrg. org/ nutshell/ faqingredients. htm#mono). Vegetarian Resource Group. . Retrieved 13 November 2011. [3] Hansen, K. B.; Rosenkilde, M. M.; Knop, F. K.; Wellner, N.; Diep, T. A.; Rehfeld, J. F.; Andersen, U. B.; Holst, J. J. et al (2011). "2-Oleoyl Glycerol is a GPR119 Agonist and Signals GLP-1 Release in Humans". Journal of Clinical Endocrinology & Metabolism 96 (9): E1409–E1417. doi:10.1210/jc.2011-0647. PMID 21778222. Diglyceride A diglyceride, or a diacylglycerol (DAG), is a glyceride consisting of two fatty acid chains covalently bonded to a glycerol molecule through ester linkages. One example, shown on the right, is Chemical structure of the diglyceride 1-palmitoyl-2-oleoyl-glycerol, which contains side-chains derived 1-palmitoyl-2-oleoyl-glycerol from palmitic acid and oleic acid. Diacylglycerols can also have many different combinations of fatty acids attached at both the C-1 and C-2 positions. Food additive Mono- and diacylglycerols are common food additives used to blend together certain ingredients, such as oil and water, which would not otherwise blend well. The commercial source may be either animal (cow- or hog-derived) or vegetable, derived primarily from partially hydrogenated soy bean and canola oil. They may also be synthetically produced. They are often found in bakery products, beverages, ice cream, peanut butter, chewing gum, shortening, whipped toppings, margarine, and confections. Biological functions Protein kinase C activation In biochemical signaling, diacylglycerol functions as a second messenger signaling lipid, and is a product of the hydrolysis of the phospholipid phosphatidylinositol 4,5-bisphosphate (PIP2) by the enzyme phospholipase C (PLC) (a membrane-bound enzyme) that, through the same reaction, produces inositol trisphosphate (IP3). Although inositol trisphosphate diffuses into the cytosol, diacylglycerol remains within the plasma membrane, due to its hydrophobic properties. IP3 stimulates the release of calcium ions from the smooth endoplasmic reticulum, whereas DAG is a physiological activator of protein kinase C (PKC). The production of DAG in the PIP2 cleavage to IP3 and DAG initiates membrane facilitates translocation of PKC from the cytosol to the intracellular calcium release and PKC activation. plasma membrane. Diacylglycerol can be mimicked by the tumor-promoting compounds phorbol esters.[1]
  18. 18. Diglyceride 16 Other In addition to activating PKC, diacylglycerol has a number of other functions in the cell: • a source for prostaglandins • a precursor of the endocannabinoid 2-arachidonoylglycerol • an activator of a subfamily of transient receptor potential canonical (TRPC) cation channels, TRPC3/6/7. Metabolism Synthesis of diacylglycerol begins with glycerol-3-phosphate, which is derived primarily from dihydroxyacetone phosphate, a product of glycolysis (usually in the cytoplasm of liver or adipose tissue cells). Glycerol-3-phosphate is first acylated with acyl-coenzyme A (acyl-CoA) to form lysophosphatidic acid, which is then acylated with another molecule of acyl-CoA to yield phosphatidic acid. Phosphatidic glycerol-3-phosphate acid is then de-phosphorylated to form diacylglycerol. Diacylglycerol is a precursor to triacylglycerol (triglyceride), which is formed in the addition of a third fatty acid to the diacylglycerol under the catalysis of diglyceride acyltransferase. Since diacylglycerol is synthesized via phosphatidic acid, it will usually contain a saturated fatty acid at the C-1 position on the glycerol moiety and an unsaturated fatty acid at the C-2 position. [2] References [1] Blumberg, PM (1988). "Protein kinase C as the receptor for the phorbol ester tumor promoters: Sixth Rhoads memorial award lecture". Cancer Research 48 (1): 1–8. PMID 3275491. [2] Berg J, Tymoczko JL, Stryer L (2006). Biochemistry (6th ed.). San Francisco: W. H. Freeman. ISBN 0-7167-8724-5.
  19. 19. Triglyceride 17 Triglyceride A triglyceride (TG, triacylglycerol, TAG, or triacylglyceride) is an ester derived from glycerol and three fatty acids.[1] There are many triglycerides: depending on the oil source, some are highly unsaturated, some less so. Saturated compounds are "saturated" with hydrogen — all available places where hydrogen atoms could be bonded to carbon atoms are Example of an unsaturated fat triglyceride. Left occupied. Unsaturated compounds have double bonds (C=C) between part: glycerol, right part from top to bottom: palmitic acid, (contains)oleic acid, alpha-linolenic carbon atoms, reducing the number of places where hydrogen atoms acid, chemical formula: C55H98O6 can bond to carbon atoms. Saturated compounds have single bonds (C-C) between the carbon atoms, and the other bond is bound to hydrogen atoms (for example =CH-CH=, -CH2-CH2-, etc.). Unsaturated fats have a lower melting point and are more likely to be liquid. Saturated fats have a higher melting point and are more likely to be solid. Triglycerides are the main constituents of vegetable oil (typically more unsaturated) and animal fats (typically more saturated).[2] In humans, triglycerides are a mechanism for storing unused calories, and their high concentration in blood correlates with the consumption of starchy and other high carbohydrate foods. Chemical structure Triglycerides are formed by combining glycerol with three molecules of fatty acid. Alcohols have a hydroxyl (HO-) group. Organic acids have a carboxyl (-COOH) group. Alcohols and organic acids join to form esters. The glycerol molecule has three hydroxyl (HO-) groups. Each fatty acid has a carboxyl group (-COOH). In triglycerides, the hydroxyl groups of the glycerol join the carboxyl groups of the fatty acid to form ester bonds: HOCH2CH(OH)CH2OH + RCO2H + RCO2H + RCO2H → RCO2CH2CH(O2CR)CR + 3H2O The three fatty acids (RCO2H, RCO2H, RCO2H in the above equation) are usually different, but many kinds of triglycerides are known. The chain lengths of the fatty acids in naturally occurring triglycerides vary, but most contain 16, 18, or 20 carbon atoms. Natural fatty acids found in plants and animals are typically composed of only even numbers of carbon atoms, reflecting the pathway for their biosynthesis from the two-carbon building-block acetyl CoA. Bacteria, however, possess the ability to synthesise odd- and branched-chain fatty acids. As a result, ruminant animal fat contains odd-numbered fatty acids, such as 15, due to the action of bacteria in the rumen. Many fatty acids are unsaturated, some are polyunsaturated, e.g., those derived from linoleic acid. Most natural fats contain a complex mixture of individual triglycerides. Because of this, they melt over a broad range of temperatures. Cocoa butter is unusual in that it is composed of only a few triglycerides, derived from palmitic, oleic, and stearic acids.
  20. 20. Triglyceride 18 Metabolism The enzyme pancreatic lipase acts at the ester bond, hydrolysing the bond and "releasing" the fatty acid. In triglyceride form, lipids cannot be absorbed by the duodenum. Fatty acids, monoglycerides (one glycerol, one fatty acid), and some diglycerides are absorbed by the duodenum, once the triglycerides have been broken down. Triglycerides, as major components of very-low-density lipoprotein (VLDL) and chylomicrons, play an important role in metabolism as energy sources and transporters of dietary fat. They contain more than twice as much energy (9 kcal/g or 38 kJ/g ) as carbohydrates and proteins. In the intestine, triglycerides are split into monoacylglycerol and free fatty acids in a process called lipolysis, with the secretion of lipases and bile, which are subsequently moved to absorptive enterocytes, cells lining the intestines. The triglycerides are rebuilt in the enterocytes from their fragments and packaged together with cholesterol and proteins to form chylomicrons. These are excreted from the cells and collected by the lymph system and transported to the large vessels near the heart before being mixed into the blood. Various tissues can capture the chylomicrons, releasing the triglycerides to be used as a source of energy. Fat and liver cells can synthesize and store triglycerides. When the body requires fatty acids as an energy source, the hormone glucagon signals the breakdown of the triglycerides by hormone-sensitive lipase to release free fatty acids. As the brain cannot utilize fatty acids as an energy source (unless converted to a ketone), the glycerol component of triglycerides can be converted into glucose, via glycolysis by conversion into Dihydroxyacetone phosphate and then into Glyceraldehyde 3-phosphate, for brain fuel when it is broken down. Fat cells may also be broken down for that reason, if the brains needs ever outweigh the bodys. Triglycerides cannot pass through cell membranes freely. Special enzymes on the walls of blood vessels called lipoprotein lipases must break down triglycerides into free fatty acids and glycerol. Fatty acids can then be taken up by cells via the fatty acid transporter (FAT). Role in disease In the human body, high levels of triglycerides in the bloodstream have been linked to atherosclerosis and, by extension, the risk of heart disease and stroke. However, the relative negative impact of raised levels of triglycerides compared to that of LDL:HDL ratios is as yet unknown. The risk can be partly accounted for by a strong inverse relationship between triglyceride level and HDL-cholesterol level. Guidelines The American Heart Association has set guidelines for triglyceride levels:[3] Level mg/dL Level mmol/L Interpretation <150 <1.70 Normal range, low risk 151-199 1.70-2.25 Slightly above normal 200-499 2.26-5.65 >500 >5.65 Very high: high risk These levels are tested after fasting 8 to 12 hours. Triglyceride levels remain temporarily higher for a period of time after eating.
  21. 21. Triglyceride 19 Reducing triglyceride levels Diets high in carbohydrates, with carbohydrates accounting for more than 60% of the total energy intake, can increase triglyceride levels.[3] Of note is how the correlation is stronger for those with higher BMI (28+) and insulin resistance (more common among overweight and obese) is a primary suspect cause of this phenomenon of carbohydrate-induced hypertriglyceridemia.[4] There is evidence that carbohydrate consumption causing a high glycemic index can cause insulin overproduction and increase triglyceride levels in women.[5] Adverse changes associated with carbohydrate intake, including triglyceride levels, are stronger risk factors for heart disease in women than in men.[6] Triglyceride levels are also reduced by exercise and by consuming omega-3 fatty acids from fish, flax seed oil, and other sources. See potential health benefits of Omega-3. Carnitine has the ability to lower blood triglyceride levels.[7] In some cases, fibrates have been used to bring down triglycerides substantially.[8] Heavy use of alcohol can elevate triglycerides levels.[9] Fish oil has been found to decrease triglycerides.[10] Industrial uses Linseed oil and related oils are important components of useful products used in oil paints and related coatings. Linseed oil is rich in di- and triunsaturated fatty acid components, which tend to harden in the presence of oxygen. The hardening process is peculiar to these so-called "drying oils". It is caused by a polymerization process that begins with oxygen molecules attacking the carbon backbone. Triglycerides are also split into their components via transesterification during the manufacture of biodiesel. The resulting fatty acid esters can be used as fuel in diesel engines. The glycerin has many uses, such as in the manufacture of food and in the production of pharmaceuticals. Staining Staining for fatty acids, triglycerides, lipoproteins, and other lipids is done through the use of lysochromes (fat-soluble dyes). These dyes can allow the qualification of a certain fat of interest by staining the material a specific color. Some examples: Sudan IV, Oil Red O, and Sudan Black B. Interactive pathway map Click on genes, proteins and metabolites below to link to respective articles. [11] [[File:
  22. 22. Triglyceride 20 <div style="display:block; width:60px; height:0px; overflow:hidden; position:relative; left:128.74774509060222px; top:130.666666666667px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:50.4999745686848px; height:0px; overflow:hidden; position:relative; left:348.0000254313152px; top:155.5px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:60px; height:0px; overflow:hidden; position:relative; left:396.1666666666667px; top:189.666666666667px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:60px; height:0px; overflow:hidden; position:relative; left:664.0px; top:146.833333333333px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:60px; height:0px; overflow:hidden; position:relative; left:159.16666666666666px; top:320.333333333333px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:60px; height:0px; overflow:hidden; position:relative; left:446.0px; top:322.833333333333px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:60px; height:0px; overflow:hidden; position:relative; left:287.5000254313151px; top:319.833333333333px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:60px; height:0px; overflow:hidden; position:relative; left:358.99999999999994px; top:348.483327229818px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:60px; height:0px; overflow:hidden; position:relative; left:207.33333333333334px; top:402.983327229818px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:60px; height:0px; overflow:hidden; position:relative; left:281.33333333333303px; top:440.833333333333px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:60px; height:0px; overflow:hidden; position:relative; left:303.33333333333354px; top:498.5px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:60px; height:0px; overflow:hidden; position:relative; left:304.33333333333354px; top:611.333333333333px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:60px; height:0px; overflow:hidden; position:relative; left:522.1666666666669px; top:456.166666666667px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:60px; height:0px; overflow:hidden; position:relative; left:468.16666666666674px; top:541px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:60.0000000000001px; height:0px; overflow:hidden; position:relative; left:608.6666666666666px; top:424.833333333334px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:60.0000000000001px; height:0px; overflow:hidden; position:relative; left:608.6666666666666px; top:404.833333333334px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:60px; height:0px; overflow:hidden; position:relative; left:668.6666666666666px; top:404.833333333334px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:60.0000000000001px; height:0px; overflow:hidden; position:relative; left:668.6666666666666px; top:424.833333333334px; background:transparent; border-top:3px blue solid"></div>
  23. 23. Triglyceride 21 <div style="display:block; width:60px; height:0px; overflow:hidden; position:relative; left:522.1666666666669px; top:436.166666666667px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:93.3333333333333px; height:0px; overflow:hidden; position:relative; left:268.3333435058594px; top:222.499994913737px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:69.1666666666666px; height:0px; overflow:hidden; position:relative; left:280.83333333333337px; top:108.333333333333px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:68.3333333333333px; height:0px; overflow:hidden; position:relative; left:194.16666666666669px; top:623.666666666667px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:65px; height:0px; overflow:hidden; position:relative; left:50.24774572638509px; top:76px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:85px; height:0px; overflow:hidden; position:relative; left:470.0px; top:223px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:55px; height:0px; overflow:hidden; position:relative; left:410.5px; top:118.5px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:74.5px; height:0px; overflow:hidden; position:relative; left:559.0px; top:199px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:80px; height:0px; overflow:hidden; position:relative; left:654.5px; top:235px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:32.0166666666667px; height:0px; overflow:hidden; position:relative; left:134.48333333333335px; top:366.483333333333px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:32.0166666666667px; height:0px; overflow:hidden; position:relative; left:298.99167989095054px; top:366.483333333333px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:32.0166666666667px; height:0px; overflow:hidden; position:relative; left:414.48333333333335px; top:387.483333333333px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:32.0166666666667px; height:0px; overflow:hidden; position:relative; left:385.98333333333335px; top:451.483333333333px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:60px; height:0px; overflow:hidden; position:relative; left:125.33333333333348px; top:560px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:60px; height:0px; overflow:hidden; position:relative; left:125.33333333333348px; top:580px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:60px; height:0px; overflow:hidden; position:relative; left:413.1666666666668px; top:610.333333333334px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:68.3333333333333px; height:0px; overflow:hidden; position:relative; left:508.6666666666667px; top:625.666666666667px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:60.0000000000001px; height:0px; overflow:hidden; position:relative; left:608.6666666666666px; top:444.833333333334px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:60.0000000000001px; height:0px; overflow:hidden; position:relative; left:668.6666666666666px; top:444.833333333334px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:49px; height:0px; overflow:hidden; position:relative; left:572.25px; top:319px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:46px; height:0px; overflow:hidden; position:relative; left:582.5px; top:100.5px; background:transparent; border-top:3px blue solid"></div>
  24. 24. Triglyceride 22 <div style="display:block; width:67px; height:0px; overflow:hidden; position:relative; left:127.0px; top:223px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:50.7522542736149px; height:0px; overflow:hidden; position:relative; left:40.24774572638509px; top:250px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:43px; height:0px; overflow:hidden; position:relative; left:202.0px; top:186px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:53.75px; height:0px; overflow:hidden; position:relative; left:497.75px; top:118.75px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:102px; height:0px; overflow:hidden; position:relative; left:430.5px; top:80.5px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:49px; height:0px; overflow:hidden; position:relative; left:572.25px; top:299px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:68.3333333333333px; height:0px; overflow:hidden; position:relative; left:359.1666666666667px; top:545.166666666667px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:60px; height:0px; overflow:hidden; position:relative; left:522.1666666666669px; top:476.166666666667px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:80px; height:0px; overflow:hidden; position:relative; left:348.17550402772156px; top:670.791244768462px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:80px; height:0px; overflow:hidden; position:relative; left:348.17550402772156px; top:690.791244768462px; background:transparent; border-top:3px blue solid"></div> <div style="display:block; width:73px; height:12px; overflow:hidden; position:relative; left:654.5px; top:218px; background:transparent; border:4px black solid"></div> {{{bSize}}}px Statin Pathway edit [12] References [1] "Nomenclature of Lipids" (http:/ / www. chem. qmul. ac. uk/ iupac/ lipid/ ). IUPAC-IUB Commission on Biochemical Nomenclature (CBN). . Retrieved 2007-03-08. [2] Nelson, D. L.; Cox, M. M. "Lehninger, Principles of Biochemistry" 3rd Ed. Worth Publishing: New York, 2000. ISBN 1-57259-153-6. [3] "Your Triglyceride Level" (http:/ / www. americanheart. org/ presenter. jhtml?identifier=183#Triglyceride). What Your Cholesterol Levels Mean. American Heart Association. . Retrieved 2009-05-22. [4] Parks, E.J. (2002). "Dietary carbohydrate’s effects on lipogenesis and the relationship of lipogenesis to blood insulin and glucose concentrations". British Journal of Nutrition 87: S247–S253. doi:10.1079/BJN/2002544. PMID 12088525. "Those with a body mass index (BMI) equal to or greater than 28 kg/m2 experienced a 30% increase in TAG concentration, while those whose BMI was less than 28, experienced no change...These data demonstrate that certain characteristics (e.g., BMI) can make some individuals more sensitive with respect to lipid and lipoprotein changes when dietary CHO is increased. Such characteristics that have been identified from previous work in this field and include BMI, insulin sensitivity (Coulston et al. 1989), concentration of TAG before the dietary change is made (Parks et al. 2001), hormone replacement therapy (Kasim-Karakas et al. 2000), and genetic factors (Dreon et al. 2000)." [5] "Focusing on Fiber?" (http:/ / www. drweil. com/ drw/ u/ id/ QAA298788). Drweil.com. . Retrieved 2010-08-02. [6] "Dietary Glycemic Load and Index and Risk of Coronary Heart Disease in a Large Italian Cohort" (http:/ / archinte. ama-assn. org/ cgi/ content/ abstract/ 170/ 7/ 640). Archives of internal medicine. . Retrieved 2010-05-01. [7] Balch, Phyllis A. Prescription for nutritional healing. 4th ed. New York: Avery, 2006. p. 54 Carnitine [8] "Fibrates: Where Are We Now?: Fibrates and Triglycerides" (http:/ / www. medscape. com/ viewarticle/ 587134_7). Medscape.com. . Retrieved 2010-08-02. [9] Hemat, R A S (2003). Principles of Orthomolecularism (http:/ / books. google. com/ ?id=ED_xI-CEzFYC& pg=PA254& lpg=PA254& dq=alcohol+ consumption+ can+ elevate+ triglyceride+ levels). Urotext. p. 254. ISBN 1-903737-06-0. . [10] "Examine - Triglycerides" (http:/ / examine. com/ topics/ Triglycerides/ ). . Retrieved 2012-04-04.
  25. 25. Triglyceride 23 [11] The interactive pathway map can be edited at WikiPathways: "Statin_Pathway_WP430" (http:/ / www. wikipathways. org/ index. php/ Pathway:WP430). . [12] http:/ / www. wikipathways. org/ index. php/ Pathway:WP430 Quaternary ammonium cation Quaternary ammonium cations, also known as quats, are positively charged polyatomic ions of the structure NR4+, R being an alkyl group or an aryl group.[1] Unlike the ammonium ion (NH4+) and the primary, secondary, or tertiary ammonium cations, the quaternary ammonium cations are permanently charged, independent of the pH of their solution. Quaternary ammonium salts or quaternary ammonium compounds (called quaternary amines in oilfield parlance) are salts of quaternary ammonium cations with an anion. Synthesis Quaternary ammonium compounds are prepared by alkylation of tertiary amines, in a process called quaternization.[2] Typically one of Quaternary ammonium cation. The R groups may the alkyl groups on the amine is larger than the others.[3] A typical be the same or different alkyl or aryl groups. Also, the R groups may be connected. synthesis is for benzalkonium chloride from a long-chain alkyldimethylamine and benzyl chloride: CH3(CH2)nN(CH3)2 + ClCH2C6H5 → CH3(CH2)nN(CH3)2CH2C6H5]+Cl- Applications Quaternary ammonium salts are used as disinfectants, surfactants, fabric softeners, and as antistatic agents (e.g. in shampoos). In liquid fabric softeners, the chloride salts are often used. In dryer anticling strips, the sulfate salts are often used. Spermicidal jellies also contain quaternary ammonium salts. As antimicrobials Quaternary ammonium compounds have also been shown to have antimicrobial activity. [4] Certain quaternary ammonium compounds, especially those containing long alkyl chains, are used as antimicrobials and disinfectants. Examples are benzalkonium chloride, benzethonium chloride, methylbenzethonium chloride, cetalkonium chloride, cetylpyridinium chloride, cetrimonium, cetrimide, dofanium chloride, tetraethylammonium bromide, didecyldimethylammonium chloride and domiphen bromide. Also good against fungi, amoeba, and enveloped viruses,[5] quats act by disrupting the cell membrane. Quaternary ammonium compounds are lethal to a wide variety of organisms except endospores, Mycobacterium tuberculosis and non-enveloped viruses. In contrast to phenolics, quaternary ammonium compounds are not very effective in the presence of organic compounds. Yet, they are very effective in combination with phenols. Quaternary ammonium compounds are deactivated by soaps, other anionic detergents, and cotton fibers.[5] Also, they are not recommended for use in hard water. Effective levels are at 200 ppm.[6] They are effective at temperatures up to 212 °F (unknown operator: ustrong °C). Along with sodium hypochlorite, quaternary ammonium salts are the primary chemicals used in foodservice industry as sanitizing agents.
  26. 26. Quaternary ammonium cation 24 As phase transfer catalysts In organic synthesis, quaternary ammonium salts are employed as phase transfer catalysts (PTC). Such catalysts accelerate reactions between reagents dissolved in immiscible solvents. The highly reactive reagent dichlorocarbene is generated via PTC by reaction of chloroform and sodium hydroxide. Osmolytes Quaternary ammonium compounds are present in osmolytes, specifically glycine betaine, which stabilize osmotic pressure in cells.[7] Health effects Quaternary ammonium compounds can display a range of health effects, amongst which are mild skin and respiratory irritation [8] up to severe caustic burns on skin and gastro-intestinal lining (depending on concentration), gastro-intestinal symptoms (e.g., nausea and vomiting), coma, convulsions, hypotension and death.[9] They are thought to be the chemical group responsible for anaphylactic reactions that occur with use of neuromuscular blocking drugs during general anaesthesia in surgery.[10] Quaternium-15 is the single most often found cause of allergic contact dermatitis of the hands (16.5% in 959 cases)[11] References [1] Nic, M.; Jirat, J.; Kosata, B., eds. (2006–). "quaternary ammonium compounds" (http:/ / goldbook. iupac. org/ Q05003. html). IUPAC Compendium of Chemical Terminology (Online ed.). doi:10.1351/goldbook.Q05003. ISBN 0-9678550-9-8. . [2] Smith, Michael B.; March, Jerry (2001), Advanced Organic Chemistry: Reactions, Mechanisms, and Structure (5th ed.), New York: Wiley-Interscience, ISBN 0-471-58589-0 [3] Kosswig, K. “Surfactants” in Ullmann’s Encyclopedia of Industrial Chemistry 2002, Wiley-VCH, Weinheim. doi:10.1002/14356007.a25_747. [4] Zhishen Jia, Dongfeng shen, Weiliang Xu, Synthesis and antibacterial activities of quaternary ammonium salt of chitosan, Carbohydrate Research, Volume 333, Issue 1, 22 June 2001, Pages 1-6, ISSN 0008-6215 (http:/ / dx. doi. org/ 10. 1016/ S0008-6215(01)00112-4) [5] Specific Antimicrobials (http:/ / www. mansfield. ohio-state. edu/ ~sabedon/ biol2032. htm), outline of lecture by Stephen T. Abedon, Ohio State U., URL accessed Dec 2008. [6] The Use of Disinfectants In the Swine Industry (http:/ / mark. asci. ncsu. edu/ HealthyHogs/ book1993/ ladd1. htm), Mark G. Ladd, North Carolina State Univ., URL accessed Dec 2008. [7] http:/ / dx. doi. org/ 10. 1128/ AEM. 67. 6. 2692-2698. 2001 Sleator, Roy D., Wouters, Jeroen, Gahan, Cormac G. M., Abee, Tjakko, Hill, Colin Analysis of the Role of OpuC, an Osmolyte Transport System, in Salt Tolerance and Virulence Potential of Listeria monocytogenes Appl. Environ. Microbiol. 2001 67: 2692-2698 [8] http:/ / www. ehjournal. net/ content/ pdf/ 1476-069x-8-11. pdf [9] http:/ / www. inchem. org/ documents/ pims/ chemical/ pimg022. htm#SectionTitle:2. 1%20%20Main%20risk%20and%20target%20organs [10] Harper, N. J. et al (2009): "Suspected anaphylactic reactions associated with anaesthesia", Anaesthesia, 64(2):199-211 [11] E. Warshaw, et al. Contact dermatitis of the hands: Cross-sectional analyses of North American Contact Dermatitis Group Data, 1994-2004. Journal of the American Academy of Dermatology, Volume 57, Issue 2, Pages 301-314 External links • Toxicities of quaternary ammonium (http://www.inchem.org/documents/pims/chemical/pimg022.htm)
  27. 27. Oil 25 Oil An oil is any substance that is liquid at ambient temperatures and does not mix with water but may mix with other oils and organic solvents. This general definition includes vegetable oils, volatile essential oils, petrochemical oils, and synthetic oils. Etymology First attested in English 1176, the word oil comes from Old French "oile", from Latin "oleum",[1] which in turn comes from the Greek "ἔλαιον" (elaion), "olive oil, oil"[2] and that from "ἐλαία" (elaia), "olive tree".[3] The earliest attested form of the word is the Mycenaean Greek e-ra-wo, written in Linear B syllabic script.[4] Types Organic oils Organic oils are produced in remarkable diversity by plants, animals, and other organisms through natural metabolic processes. Lipid is the scientific term for the fatty acids, steroids and similar chemicals often found in the oils produced by living things, while oil refers to an overall mixture of chemicals. Organic oils may also contain chemicals other than lipids, including proteins, waxes and alkaloids. Lipids can be classified by the way that they are made by an organism, their chemical structure and their limited solubility in water compared to oils. They have a high carbon and hydrogen content and are considerably lacking in oxygen compared to other organic compounds and minerals; they tend to be relatively nonpolar molecules, but may include both polar and nonpolar regions as in the case of phospholipids and steroids.[5] Mineral oils Crude oil, or petroleum, and its refined components, collectively termed petrochemicals, are crucial resources in the modern economy. Crude oil originates from ancient fossilized organic materials, such as zooplankton and algae, which geochemical processes convert into oil.[6] It is classified as a mineral oil because it does not have an organic origin on human timescales, but is instead obtained from rocks, underground traps, or sands. Mineral oil also refers to several specific distillates of crude oil.
  28. 28. Oil 26 Applications Cosmetics Oils are applied to hair to give it a lustrous look, to prevent tangles and roughness and to stabilize the hair to promote growth. See Hair conditioner. Religion Oils are commonly used in ritual anointments. As a particular example, holy anointing oil has been an important ritual liquid for Judaism and Christianity. Painting Color pigments are easily suspended in oil, making it suitable as a supporting medium for paints. The oldest known extant oil paintings date from 650 AD.[7] Heat transfer Oils are used as coolants in oil cooling, for instance in electric transformers. Oils are also used A bottle of olive oil used in food to enhance heating in other applications, such as cooking (especially in frying). Lubrication Oils are commonly used as lubricants. Mineral oils are more commonly used as machine lubricants than biological oils are. Fuel Some oils burn in liquid or aerosol form, generating heat which can be used directly or converted into other forms of energy such as electricity or mechanical work. To obtain many fuel oils, crude oil is pumped from the ground and is shipped via oil tanker to an oil refinery. There, it is converted from crude oil to diesel fuel (petrodiesel), ethane (and other short-chain alkanes), fuel oils (heaviest of commercial fuels, used in ships/furnaces), gasoline (petrol), jet fuel, kerosene, benzene (historically), and liquefied petroleum gas. A 42 gallon barrel (U.S.) of crude oil produces approximately 10 gallons of diesel, 4 gallons of jet fuel, 19 gallons of gasoline, 7 gallons of other products, 3 gallons split between heavy fuel oil and liquified petroleum gases,[8] and 2 gallons of heating oil. The total production of a barrel of crude into various products results in an increase to 45 gallons.[8] Not all oils used as fuels are mineral oils, see biodiesel and vegetable oil fuel.
  29. 29. Oil 27 Chemical feedstock Crude oil can be refined into a wide variety of component hydrocarbons. Petrochemicals are the refined components of crude oil and the chemical products made from them. They are used as detergents, fertilizers, medicines, paints, plastics, synthetic fibers, and synthetic rubber. Organic oils are another important chemical feedstock, especially in green chemistry. References [1] oleum (http:/ / www. perseus. tufts. edu/ hopper/ text?doc=Perseus:text:1999. 04. 0059:entry=oleum), Charlton T. Lewis, Charles Short, A Latin Dictionary, on Perseus Digital Library [2] ἔλαιον (http:/ / www. perseus. tufts. edu/ hopper/ text?doc=Perseus:text:1999. 04. 0057:entry=e)/ laion), Henry George Liddell, Robert Scott, A Greek-English Lexicon, on Perseus Digital Library [3] ἐλαία (http:/ / www. perseus. tufts. edu/ hopper/ text?doc=Perseus:text:1999. 04. 0057:entry=e)lai/ a), Henry George Liddell, Robert Scott, A Greek-English Lexicon, on Perseus Digital Library [4] Palaeolexicon (http:/ / www. palaeolexicon. com/ ), Word study tool of ancient languages [5] Alberts, Bruce; Johnson, Alexander; Lewis, Julian; Raff, Martin; Roberts, Keith; Walter, Peter. Molecular Biology of the Cell. New York: Garland Science, 2002, pp. 62, 118-119. [6] Kvenvolden, Keith A. (2006). "Organic geochemistry – A retrospective of its first 70 years". Organic Geochemistry 37: 1. doi:10.1016/j.orggeochem.2005.09.001. [7] "Oldest Oil Paintings Found in Afghanistan" (http:/ / dsc. discovery. com/ news/ 2008/ 02/ 19/ oldest-oil-painting. html), Rosella Lorenzi, Discovery News. Feb. 19, 2008. [8] U.S. Energy Information Administration (EIA) (http:/ / www. eia. gov/ energyexplained/ index. cfm?page=oil_home) — Retrieved 2011-10-02. External links • Petroleum Online e-Learning resource from IHRDC (http://www.petroleumonline.com) 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 and composition. Although the words "oils", "fats", and "lipids" are all used to refer to fats, "oils" is usually used to refer to fats that are liquids at normal room temperature, while "fats" is usually used to refer to fats that are solids at normal room temperature. "Lipids" is used to refer to both liquid and solid fats, along with other related substances, usually in a medical or biochemical context. The word "oil" is also used for any substance that does not mix with water and has a greasy feel, such as petroleum (or crude oil), heating oil, and essential oils, regardless of its chemical structure.[1] Fats form a category of lipid, distinguished from other lipids by their chemical structure and physical properties. This category of molecules is important for many forms of life, serving both structural and metabolic functions. They are an important part of the diet of most heterotrophs (including humans). Fats or lipids are broken down in the body by enzymes called lipases produced in the pancreas. Examples of edible animal fats are lard, fish oil, butter/ghee and whale blubber. They are obtained from fats in the milk and meat, as well as from under the skin, of an animal. Examples of edible plant fats include peanut, soya bean, sunflower, sesame, coconut and olive oils, and cocoa butter. Vegetable shortening, used mainly for baking, and margarine, used in baking and as a spread, can be derived from the above oils by hydrogenation. These examples of fats can be categorized into saturated fats and unsaturated fats. Unsaturated fats can be further divided into cis fats, which are the most common in nature, and trans fats, which are rare in nature but present in partially hydrogenated vegetable oils.