Butter fatty acid source

Cocoa butter substitutes and equivalents differ greatly with respect to their method of manufacture, source of fats, and functionaHty they are produced by several physical and chemical processes (17,18). Cocoa butter substitutes are produced from lauric acid fats such as coconut, palm, and palm kernel oils by fractionation and hydrogenation from domestic fats such as soy, com, and cotton seed oils by selective hydrogenation or from palm kernel stearines by fractionation. Cocoa butter equivalents can be produced from palm kernel oil and other specialty fats such as shea and ilHpe by fractional crystallization from glycerol and selected fatty acids by direct chemical synthesis or from edible beef tallow by acetone crystallization. 

Small amounts of trans-unsamrated fatty acids are found in ruminant fat (eg, butter fat has 2-7%), where they arise from the action of microorganisms in the rumen, but the main source in the human diet is from partially hydrogenated vegetable oils (eg, margarine). Trans fatty acids compete with essential fatty acids and may exacerbate essential fatty acid deficiency. Moreover, they are strucmrally similar to samrated fatty acids (Chapter 14) and have comparable effects in the promotion of hypercholesterolemia and atherosclerosis (Chapter 26). 

The main difference between oils and fats is that oils are liquid at room temperature and fats are solid at room temperature. Oils, such as olive oil or corn oil, usually come from plant sources and contain mainly unsaturated fatty acids. Fats, such as butter and lard, contain an abundance of saturated fatty acids and generally come from animal sources. 

Butyric acid is a carboxylic acid also classified as a fatty acid. It exists in two isomeric forms as shown previously, but this entry focuses on n-butyric acid or butanoic acid. It is a colorless, viscous, rancid-smelling liquid that is present as esters in animal fats and plant oils. Butyric acid exists as a glyceride in butter, with a concentration of about 4% dairy and egg products are a primary source of butyric acid. When butter or other food products go rancid, free butyric acid is liberated by hydrolysis, producing the rancid smell. It also occurs in animal fat and plant oils. Butyric acid gets its name from the Latin butyrum, or butter. It was discovered by Adolf Lieben (1836—1914) and Antonio Rossi in 1869. 

Stearic acid is a long chain SFA present, to varying degrees, in virtually all edible fats and oils. Table IV provides the fatty acid composition of fats and oils commonly consumed by humans. The most abundant food sources of stearic acid in the American diet are beef fat and cocoa butter (chocolate). Cocoa butter is valued by chocolate manufacturers because it remains solid at room temperature but dissolves quickly at body temperature, a unique characteristic of chocolate that is due largely to stearic acid. During the last few decades as cocoa butter prices and supplies have fluctuated, food companies began looking for alternative oils that could provide equivalent amounts of stearic acid in order to retain the desirable physical characteristics. Several... 

Woo, A.H., Lindsay, R.C. 1983b. Stepwise discriminant analysis of free fatty acid profiles for identifying sources of lipolytic enzymes in rancid butter. J. Dairy Sci. 66, 2070-2075. 

Several aliphatic carboxylic acids have been known for centuries, and their common names reflect their historical sources. Formic acid was extracted from ants formica in Latin. Acetic acid was isolated from vinegar, called acetum ( sour ) in Latin. Propionic acid was considered to be the first fatty acid, and the name is derived from the Greek protos pion ( first fat ). Butyric acid results from the oxidation of butyraldehyde, the principal flavor of butter butyrum in Latin. Caproic, caprylic, and capric acids are found in the skin secrehons of goats caper in Lahn. The names and physical properties of some carboxylic acids are listed in Table 20-1. 

The names of common fatty acids under several conventions, carbon numbers, and selected properties are shown in Table 34.1. The common (trivial) names of some fatty acids are of long standing, and often indicate the initial source studied. As examples butyric acid is a major component of butter flavor the 6, 8, and 10 saturated fatty acids have been called the goaty acids because they impart the characteristic flavors of goat and... 

Lipase splits fatty acids from glycerol to produce free fatty acids, for example, butyric acid. If the original fat is butterfat then at low levels this produces a buttery or creamy flavour. As the free fatty acid content is increased, this strengthens the flavour to cheesy . Normally in toffees free butyric acid is not a problem at any practical level, possibly because of losses during cooking. Other free fatty acids have different flavours. Laurie acid, which is found in nuts, tastes of soap. This is not too surprising as soap often contains sodium laurate. Laurie fat sources, such as hardened palm kernel oil, are often used as a substitute for butter another potential source is nuts, which are sometimes combined with toffee. In any of these cases, lipolytic activity can shorten the shelf life of the product or render it totally unacceptable. 

The trivial names that indicate the initial source of fatty acids are used more often than the lUPAC names in the industry. For example, butyric acid is a major component of butter flavor, palmitic acid comes from palm kernel, and oleic acid from olives. 

The above list does not include cocoa butter nor minor oils such as rice bran oil or safflower oil. Nor does it distinguish between oils from a common botanical source with a modified fatty acid composition, such as canola oil and high-erucic rape seed oil, linseed oil and linola, or the various types of sunflower oil. 

Shea (Butyrospermum parkii, shea butter, karite butter). This fat comes from trees grown mainly in West Africa and contains an unusually high level of unsapo-nifiable material ( 11%), including polyisoprene hydrocarbons. It is rich in stearic acid, but its fatty acid composition varies with its geographical source. It contains palmitic (4—8%), stearic (23-58%), oleic (33-68%), and hnoleic acid (4—8%). It can be fractionated to give a stearin (POP 1%, POSt 8%, and StOSt 68%), which can be used as a cocoa butter equivalent (79, 122-124). It is one of the six permitted fats (palm oil, iUipe butter, kokum butter, sal fat, shea butter, and mango kernel fat), which, in some countries at least, can partially replace cocoa butter in chocolate (86). 

An increasing problem is lipolysis in butter fat after manufacturing, which is caused by thermoresistant hpase enzymes that are created in the milk or cream by psycho-trophic bacteria or by residual native lipases that sirrvive pasteurization. Based on a determination of the lipase activity in cream, the keeping quality of manufactured butter in regard to hpolysis can be predicted with reasonable accirracy. A similar prediction for sweet cream butter can be based on lipase activity in the serum phase (71). The characteristic lipolytic flavors that can develop in milk products are primarily associated with the short- and medium-chain fatty acids that are relatively abundant in milkfat they have lower flavor threshold values than the long-chain fatty acids. As a result of improvements in the quality of raw milk and the standards of processing, lipolytic rancidity is seldom present in the fat source before its use in recombination (72). 

Triglycerides can be either solids or liquids at room temperature. If hquid, they are usually called oils. If solid at room temperature, they re called fats. Most mixtures of triglycerides from plant sources, such as corn, olive, and peanut oils, are liquids because the triglycerides contain unsaturated fatty acids that have fairly low melting points. Animal fats, such as butter, contain a larger proportion of saturated fatty acids. They have higher melting points and usually are solids at room temperature. 

Use Food products (margarine, hydrogenated shortenings) synthetic cocoa butter soaps cosmetics emulsions cotton dyeing synthetic detergents source of fatty acids, fatty alcohols, and methyl esters base for laundering and cleaning preparations for soft leathers. 

As Table 15.1 shows, many carboxylic acids occur in nature. Fatty acids can be isolated from a variety of sources including palm oil, coconut oil, butter, milk, lard, and tallow (beef fat). More complex carboxylic acids are also found in a variety of foodstuffs. For example, citric acid is found in citrus fruits and is often used to give the sharp taste to sour candies. It is also added to foods as a preservative and antioxidant. Adipic acid (hexanedioic acid) gives tartness to soft drinks and helps to retard spoilage. 

Fats and oils become rancid on standing, i.e., they develop disagreeable odors and tastes. Two reactions are involved in this process—hydrolysis and oxidation. Hydrolysis is important as a source of rancid odors only for certain triacylglycerols that contain C4 and C, carboxylic acids. Butter is an example—its triacylglycerols contain about 3 to 4 percent butanoic acid and about 1 to 2 percent hexanoic acid. Hydrolysis due to bacteria from the air releases these volatile and malodorous acids. Air oxidation of the double bonds of unsaturated fatty acids released by bacterial hydrolysis also contributes to rancidity. Oxidation cleaves the double bond, with each carbon of the double bond being converted to a COOH group. 

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