Saturated fats and oils

According to many nutrition scientists, foods that contain double or triple bonds (unsaturated compounds) are healthier for us than foods that contain single bonds (saturated compounds). Research the implications of including unsaturated and saturated fats and oils in your diet. Use a library, the Internet, or any other sources of information. Decide on a suitable format in which to present your findings. 

Occurrence Egg yolk, liver, kidneys, saturated fats and oils. All body cells contain cholesterol produced by the liver (approximately 1000 mg a day). 

These compounds are called unsaturated hydrocarbons because they don t have the maximum possible number of hydrogen atoms attached to the carbons. (I ni sure that you ve heard the terms saturated and unsaturated used in regard to fats and oils in nutrition discussions. They mean exactly the same thing there — saturated fats and oils contain no carbon-to-carbon double bonds, unsaturated fats and oils do, and polyunsaturated fats and oils have more than one C=C per molecule.)... 

Fats and oils may be synthesized in enantiomerically pure forms in the laboratory (30) or derived from vegetable sources (mainly from nuts, beans, and seeds), animal depot fats, fish, or marine mammals. Oils obtained from other sources differ markedly in their fatty acid distribution. Table 2 shows compositions for a wide variety of oils. One variation in composition is the chain length of the fatty acid. Butterfat, for example, has a fairly high concentration of short- and medium-chain saturated fatty acids. Oils derived from cuphea are also a rich source of capric acid which is considered to be medium in chain length (32). Palm kernel and coconut oils are known as lauric oils because of their high content of C-12 saturated fatty acid (lauric acid). Rapeseed oil, on the other hand, has a fairly high concentration of long-chain (C-20 and C-22) fatty acids. 

Carboxylate soaps are most commonly formed through either direct or indirect reaction of aqueous caustic soda, ie, alkaH earth metal hydroxides such as NaOH, with fats and oils from natural sources, ie, triglycerides. Fats and oils are typically composed of both saturated and unsaturated fatty acid molecules containing between 8 and 20 carbons randomly linked through ester bonds to a glycerol [56-81-5] backbone. Overall, the reaction of caustic with triglyceride yields glycerol (qv) and soap in a reaction known as saponification. The reaction is shown in equation 1. 

There are essentially four steps or unit operations in the manufacture of fatty acids from natural fats and oils (/) batch alkaline hydrolysis or continuous high pressure hydrolysis (2) separation of the fatty acids usually by a continuous solvent crystallisation process or by the hydrophilisation process (J) hydrogenation, which converts unsaturated fatty acids to saturated fatty acids and (4) distillation, which separates components by their boiling points or vapor pressures. A good review of the production of fatty acids has been given (1). 

Although vegetable oils usually contain a higher proportion of nnsatnrated fatty acids than do animal oils and fats, several plant oils are actually high in saturated fats. Palm oil is low in polyunsaturated fatty acids and particularly high in (saturated) palmitic acid (whence the name palmitic). Coconut oil is particularly high in lanric and myristic acids (both saturated) and contains very few nnsatnrated fatty acids. 

The composition of some common fets end oils. Fatty acids provide the R. R, and R" hydrocarbon residues in the general structure of a fat or oil shown in the text. Fats and oils all contain a mixture of saturated, monounsaturated. and polyunsaturated fatty acids. 

Fatty acids occur mainly as esters in natural fats and oils but do occur in the unesterified form as free fatty acids, a transport form found in the plasma. Fatty acids that occur in natural fats are usually straight-chain derivatives containing an even number of carbon atoms. The chain may be saturated (containing no double bonds) or unsaturated (containing one or more double bonds). 

There is a much wider choice of hydrophobes. Most are based on substantially linear long-chain alkanes, either saturated or unsaturated. These were originally obtained from naturally occurring fats and oils such as castor, fish, olive, sperm, coconut and tallow oils, but these sources were later superseded by petroleum products which at that time were cheaper. More recently, not only has the price of crude oil escalated, but there has also been a growing... 

Fatty acids can then be classified by their degree of unsaturation as well as their chain length. Thus, fatty acids are either saturated if they have no double bonds or unsaturated. Unsaturated fatty acids are further subdivided into monounsaturated diunsaturated and so on. Fatty acids with many double bonds are classed as polyunsaturated. Table 3 gives the approximate fatty acid compositions of several fats and oils, Table 4 lists the unsaturated fatty acids found in milk (note the very wide diversity). 

Catalytical studies of synthesized products were tested according to the Hanus Method [18]. Since Triglycerides (fats and oils) are esters of glycerol with three fatty acids. These long chain fatty acids may contain one or more double bonds. With no double bonds, the fatty acid is termed saturated (with hydrogen), and with double bonds, it is termed unsaturated. The iodine number is an indication of the degree of unsaturation of the oil (Scheme 14.4). 

Fats and oils are esters of the trihydric alcohol glycerol with long-chain fatty acids. The descriptor fat or oil is applied according to whether the material is a solid or liquid at room temperature it has no chemical meaning. All three fatty acids in the ester may be the same, or they may be different. Common saturated fatty acids... 

Cardiovascular effect. Coconut and coconut oil, administered to 32 coronary heart disease patients in 16 age- and sex-matched healthy controls with no difference in the fat, saturated fat, and cholesterol consumption, produced no effecC h Hydrogenated oil, administered to young male Wistar rats, at a dose of 10% of diet for 10 weeks, produced an increase in the risk of ventricular arrhythmias under conditions of both ischemia and reperfusion. The incidence of ventricular fibrillation was 67% in the oil-... 

Fats and oils usually contain fatty acids in their free form as a result of spontaneous hydrolysis of the parent TG compounds. These free fatty acids (FFAs) are usually linear molecules with 4—24 carbon atoms that may be saturated or unsaturated with typically 1-3 C=C double bonds. Other compounds, such as pigments, waxes, sterols, glycolipids, lipoproteins, hydrocarbons, long chain alcohols, carbohydrates and vitamins (E, A and D), can also be found in oils and fats in minor concentrations. 

Much research is currently underway to determine whether a correlation exists between cholesterol levels in the blood and diet. Cholesterol not only comes from the diet, but is also synthesized in the body from carbohydrates and proteins as well as fat. Therefore, the elimination of cholesterol rich foods from the diet does not necessarily lower blood cholesterol levels. Some studies have found that if certain unsaturated fats and oils are substituted for saturated fats the blood cholesterol level decreases. 

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. 

FATTY AMINE. A normal aliphatic amine derived from fats and oils. May be saturated or unsaturaied. and primary, secondary, or Icliary. but the alkyl groups are straight chain and have an even number of carbons in each. The length varies from 8 to 22 carbon atoms. 

Hydrogenation—any reaction of hydrogen with an organic compound. In the case of fats and oils, this is the direct addition of hydrogen to double bonds of unsaturated molecules, resulting in a partially or a fully saturated product. 

Miwa and Yamamoto (31) described a simple and rapid method with high accuracy and reliability for the determination of C8 0-C22 6 fatty acids, which occur in esterified forms in dietary fats and oils and in living cells [the biological effects of routinely consumed fats and oils are of wide interest because of their impact on human health and nutrition (28,29), in particular, the ratio of cu-3 polyunsaturated fatty acid to w-6 polyunsaturated fatty acids (w-3/cu-6) seems to be associated with atherosclerosis and breast and colon cancers (30)]. They report improved separation of 29 saturated and mono- and polyunsaturated fatty acids (C8-C22), including cis-trans isomers and double-bond positional isomers, as hydrazides formed by direct derivatization with 2-nitrophenylhydrazine hydrochloride (2-NPH HC1) of saponified samples without extraction. The column consisted of a J sphere ODS-M 80 column (particle size 4 /xm, 250 X 4.6-mm ID), packed closely with spherical silica encapsulated to reach a carbon content of about 14% with end-capped octadecyl-bonded-spherical silica (ODS), maintained at 50°C. The solvent system was acetonitrile-water (86 14, v/v) maintained at pH 4-5 by adding 0.1 M hydrochloric acid with a flow rate of 2.0 ml/min. Separation was performed within only 22 min by a simple isocratic elution (Fig. 6). The resolution of double-bond positional isomers, such as y-linolenic ( >-6) and a-linolenic acid ( >-3) hydrazides and w-9, >-12, and >-15 eicosenoic acid hydrazides was achieved by use of this column. 

In Chapter 20, we discussed the health-threatening situation that often arises from excess cholesterol. In this regard, vegetable fats and oils are better for humans than animal fats because they contain no cholesterol and less of the saturated fatty acids that lead to elevated levels of blood cholesterol (see tables 4 and 5). 

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