Saturated fatty stearic

The saturated fatty acids, stearic [57-11-4] and palmitic [57-10-3], are found in animal fats and dairy products. Extensive studies point to the deleterious effect of these acids on arterial walls as a result it is recommended that saturated fatty acid intake be carefully controlled and intake limited (23). 

Hydrogena.tlon. Lecithin can be hydrogenated. The resulting lecithins have only saturated fatty acid residues (palmitic or stearic acid) and are more or less colorless and crystalline. 

More than LOO different fatty acids are known, and about 40 occur widely. Palmitic acid (C ) and stearic acid (Cjy) are the most abundant saturated fatty adds oleic and linoleic acids (both Care the most abundant unsaturated ones. Oleic acid is monounsaturated since it has only one double bond, whereas linoleic, linolenic, and arachidonic acids are polyunsaturated fatty acids because they have more than one double bond. Linoleic and linolenic... 

Stearic acid is a saturated fatty acid. This means it has only single bonds between its carbon atoms. This means it can coil up and form into random shapes. Double bonds between carbon atoms restrict the bending of the molecule at the point of the bond, like a hinge that lets a door swing back and forth but not up and down. Triple bonds are even more restrictive, locking the joint in place three-dimensionally, like the legs of a tripod. 

Most of the technically produced a-sulfo fatty esters are prepared from unbranched saturated fatty acid esters that are derived from 8 22 carboxylic acids and Cj-C3 alcohols. In particular the C12 (lauric), C14 (myristic), C16 (palmitic), and C18 (stearic) acids are interesting because the ester sulfonates... 

Laurie, myristic, palmitic, and stearic fatty acids make up most of the saturated fatty acids found in fats. Oleic acid, linoleic acid, and linolenic acid are the most abundant unsaturated fatty acids found in oils. 

A compounding ingredient that enables an accelerator to exercise its maximum effect. Inorganic activators are metallic oxides (such as zinc, lead and magnesium oxides) and organic activators are long-chain saturated fatty acids, e.g., stearic and oleic. 

Figure 11.1 Structures of commonly occurring saturated fatty acids (i) myristic acid, Ci4 o (ii) palmitic acid, C s-.o (iii) stearic acid, Ci8 0.

The fatty acids with an even number of carbon atoms most frequently involved in acylglycerols are palmitic, stearic, oleic and linoleic, while odd-numbered and branched chain fatty acids only occur infrequently. Animal acylglycerols contain mainly saturated fatty acids although many fish oils are... 

The common fatty acids have a linear chain containing an even number of carbon atoms, which reflects that the fatty acid chain is built up two carbon atoms at a time during biosynthesis. The structures and common names for several common fatty acids are provided in table 18.1. Fatty acids such as palmitic and stearic acids contain only carbon-carbon single bonds and are termed saturated. Other fatty acids such as oleic acid contain a single carbon-carbon double bond and are termed monounsaturated. Note that the geometry around this bond is cis, not trans. Oleic acid is found in high concentration in olive oil, which is low in saturated fatty acids. In fact, about 83% of all fatty acids in olive oil is oleic acid. Another 7% is linoleic acid. The remainder, only 10%, is saturated fatty acids. Butter, in contrast, contains about 25% oleic acid and more than 35% saturated fatty acids. 

This finding has been replicated several times in clinical studies. Let me cite one example. In a careful metabolic study carried out in 1990, Mensink and Katan determined the plasma LDL/HDL ratio when 10% of the energy from oleic acid was replaced in the diet by either the corresponding trans fat or the corresponding saturated fatty acid, stearic acid. The resulting LDL/HDL ratios were 2.02 on the oleic acid diet, 2.34 on the stearic acid diet, and 2.58 on the trans fatty acid diet. This is one more example of the impact of small structural changes in molecules on their biological properties. 

Saturated fatty acids are named, systematically, according to the number of carbon atoms with the addition of the suffix -anoic. hence the systematic name for stearic acid, which has 18 carbon atoms, is octadecanoic acid. 

Saturated fatty acids (no double bonds), such as myristic, palmitic, and stearic, make up two-thirds of milk fatty acids. Oleic acid is the most abundant unsaturated fatty acid in milk, with one double bond. Triglycerides account for 98% of milk fat. The small amounts of mono-, diglycerides, and free fatty acids in fresh milk may be... 

Butyric acid is one of the simplest fatty acids. Fatty acids, which are the building units of fats and oils, are natural compounds of carbon chains with a carboxyl group (-COOH) at one end. Most natural fatty acids have an unbranched carbon chain and contain an even number of carbon atoms because during biosynthesis they are built in two carbon units from acetyl coenzyme A (CoA). Butyric acid is an unsaturated fatty acid, which means all carbon-carbon bonds are single bonds. Common names for fatty acids stem from their natural sources. In addition to butyric acid, some other common saturated fatty acids include lauric acid, palmitic acid, and stearic acid. Lauric acid was first discovered in Lauraceae (Laurus nobilis) seeds, palmitic oil was prepared from palm oil, and stearic acid was discovered in animal fat and gets its name from the Greek word stear for tallow. 

In contrast to the anaerobic pathway found in E. coli, the aerobic pathway in eukaryotic cells introduces double bonds after the saturated fatty acid has been synthesized. Stearoyl-CoA (18 0) is the major substrate for desaturation. Stearic acid is made by the fatty acid synthase as a minor product, the major product being palmitic acid, and is activated to its CoA derivative by acyl-CoA synthase. In eukaryotic cells an enzyme complex associated with the endoplasmic reticulum desaturates stearoyl-CoA to oleoyl-CoA (18 1A9). This remarkable reaction requires NADH and 02 and results in the formation of a double bond in the middle of an acyl chain with no activating groups nearby. The chemical mechanism for desaturation of long-chain acyl-CoAs remains unclear. 

It is important to bear in mind when discussing the effect of dairy fat in association to heart disease that dairy products contain many different saturated fatty acids that do not exert the same biological response in terms of, for example, cholesterol levels. The saturated fatty acids in milk fat include shorter and medium chain fatty acids (2 0-10 0), lauric acid (12 0), myristic acid (14 0), palmitic acid (16 0), and stearic acid (18 0). Other fatty acids in milk fat are oleic acid (18 1) and linoleic acid (18 2n-6) as indicated in Table 1.2. 

Saturated fatty acids (FAs) such as stearic acid are susceptible to degradation reactions typical of those for carboxyl groups. When... 

Whole soybeans contain 360-370 g/kg CP, whereas soybean meal contains 410-500 g/kg CP depending on efficiency of the oil-extraction process and the amount of residual hulls present. The oil has a high content of the polyunsaturated fatty acids, linoleic (08 2) and linolenic (08 3) acids. It also contains high amounts of another unsaturated fatty acid, oleic (08 1) and moderate amounts of the saturated fatty acids, palmitic (06 0) and stearic (08 0). 

Figure 12.22 gives the most common saturated fatty acids. The IUPAC names are given first. For dodecanoic acid, C12F12402, the parent chain has twelve carbons (do = 2 + deca = 10). The common names of the fatty acids are roughly derived from fats and oils that are rich in that fatty acid. For example, palm and palm kernel oils are rich in palmitic acid. Beef tallow is rich in stearic acid. Although stearic sounds a little bit like steers, it is derived from the Greek word for tallow. 

The vegetable oil used was rapeseed oil (Nacalai Tesque Kyoto, Japan) without further treatment. The fatty acid content of the rapeseed oil mainly consisted of unsaturated fatty acids (93 wt%), with the saturated fatty acids of palmitic and stearic acids accounting for only a small amount (7 wt%). Various fatty acids of oleic (C181), linoleic (C18 2), linolenic (C18 3), and palmitic (C16 0) acids as well as their methyl esters were purchased from Nacalai Tesque. Anhydrous methanol and distilled water were also supplied by the same company. 

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