Cocoa butter stearic acid

The non-specificity of the immobilized lipase can be demonstrated in several ways. We used a convenient acidolytic test system where cocoa butter (stearic fraction) was interesterified with lauric acid (8). The test principles are outlined in Table II. 

The fatty acids that concern us from a dietary point of view range in length from Cjj to Cjg. The acids may contain one or more double bonds the presence of the double bonds lowers the melting point of the fat, because the chains pack less well. In the Cjg series (Figure 11.96), we can identify stearic acid (saturated, mainly found in animal fats but also in cocoa butter), oleic acid (one double bond, the triglyceride is the main constituent of olive oil) linoleic acid (two double bonds, one of the essential fatty acids that we must consume for good health, found in safflower, sunflower, and corn oil), and linolenic acid (three double bonds, another essential fatty acid, found in canola, soya, and walnuts). In this series (and related ones), the saturated fats are solids, whereas the unsaturated fats are liquids at room temperature. So in order to... 

Cocoa butter is composed mainly of glycerides of stearic, palmitic, and oleic fatty acids (see Eats AND FATTY oils). The triglyceride stmcture of cocoa butter has been determined (11,12) and is as foUows ... 

Stearic acid is the most common of the long-chain fatty acids. It is found in many foods, such as beef fat and cocoa butter. It is widely used as a lubricant in soaps, cosmetics, food packaging, deodorant sticks, and toothpastes. It is also a commonly used softener in rubber. 

Some plants produce a mixture of fatty acids (Table 11.3). The fat in seeds of the cacao tree (Theobroma cacao) contains a mixture of stearic and palmitic acids. The fat is known as cocoa butter from its resemblance to the butter produced from cow s milk (see Box 11.2). 

The main current potential application of lipase-catalyzed fat-modification processes is in the production of valuable confectionery fats for instance, alternative methods of obtaining cocoa-butter equivalents by converting cheap palm-oil fats and stearic acid to cocoa-butter-like fats. The reaction is executed in a water-poor medium, such as hexane, to prevent hydrolysis. At least one commercial apphcation exists. Loders Croklaan (Unilever) has an enzymatic interesterification plant in Wormerveer, the Netherlands. Many other new potential applications of lipases have been proposed of which some will certainly be economically feasible. Examples and details can be found in chapter 9 of this book. 

Cocoa seeds contain 35-50% of oil (cocoa butter or theobroma oil), 1-4% theobromine and 0.2-0.5% caffeine, plus tannins and volatile oils. During fermentation and roasting, most of the theobromine from the kernel passes into the husk, which thus provides a convenient source of the alkaloid. Theobroma oil or cocoa butter is obtained by hot expression from the ground seeds as a whitish solid with a mild chocolate taste. It is a valuable formulation aid in pharmacy where it is used as a suppository base. It contains glycerides of oleic (35%), stearic (35%), palmitic (26%), and linoleic (3%) acids (see page 44). 

The appeal of chocolate is universal, but the pleasures of eating chocolate products may perhaps be tempered by their fat and sugar content. However, in a series of human feeding studies it has been shown that the high proportion of stearic acid in the cocoa butter of chocolate does not adversely affect plasma lipids. Two recent reports of antioxidant activity have increased interest in the health aspects of chocolate an in vitro low-density liposprotein (LDL) oxidation study and a short-term in vivo study. Epicatechin, the major monomeric polyphenol antioxidant in chocolate, and an extract of chocolate liquor were both found to stimulate cellular immune response in vitro. 

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... 

Stearic acid n-Octadecanoic acid 18 Cocoa butter, animal, fat... 

Glyceryl Tristearate occurs as a white, microfine, crystalline powder. It is prepared by reacting glycerin with stearic acid in the presence of a suitable catalyst such as aluminum oxide. It is also found in many animal and vegetable fats such as tallow and cocoa butter. It is soluble in hot alcohol and in chloroform very slightly soluble in cold alcohol, in ether, and in petroleum ether but insoluble in water. 

The complexity of chocolate manufacture arises from the polymorphic nature of its constituent fats, which can come in at least five crystal forms, each with an individual melting point. Cocoa butter is chemically a multicomponent mixture of triglycerides and trace compounds (Davis and Dimick 1986). Approximately 85% of the composition consists of just three triglycerides POP ( 20%), POS ( 40%) and SOS ( 25%), where palmitic (P), oleic (O) and stearic (S) are the fatty acids attached to the glycerol base. The precise composition depends on factors such as growing conditions and therefore can vary between batches, especially from different geographic regions (Chaiseri and Dimick 1989). 

Unlike many fats and oils, the cocoa butter used to make chocolate is remarkably uniform in composition. All triacylglycerols contain oleic acid esterified to the 2° OH group of glycerol, and either palmitic acid or stearic acid esterified to the 1 ° OH groups. Draw the structures of two possible triacylglycerols that compose cocoa butter. 

Octadecanoic Stearic 69.6 Major fatty acid in animal tissues and some fungi, usually minor in plants, major only in a few plant species (e.g., cocoa butter). 

Borneo tallow Sfiorea stenoptera). This solid fat, also known as iUipe butter, contains palmitic (18%), stearic (46%), and oleic acid (35%). It is one of six permitted fats (palm oil, Ulipe 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, 87). 

Sal fat (Shorea robusta). This tree, which grows in Northern India, is felled for timber. Its seed oil is rich in stearic acid, and it can be used as a cocoa butter equivalent (CBE). The major acids are palmitic (2-8%), stearic (35 8%), oleic (35 2%), linoleic (2-3%), and arachidic acid (6-11%). Its major triacylglycerols are of the SUS type required of a cocoa butter equivalent. Sal olein is an excellent emolhent, and sal stearin, with POP 1%, POSt 13%, and StOSt 60%, is a superior cocoa butter equivalent (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). 

Unilever developed a method for upgrading palm mid-fraction (PMF) as a cocoa butter equivalent. The PMF is too rich in palmitic acid and has too little stearic acid, but this deficiency can be repaired by enzyme-catalysed acidolysis with stearic acid. Reaction is confined to the exchange of palmitic acid by stearic acid at the sn-1 and 3 positions with no movement of oleic acid from the sn-2 position. A similar product is produced enzymatically by acidolysis of high-oleic sunflower oil (rich in triolein) and stearic acid. 

Symmetrical stearic acid containing TAGs with oleic acid in the iw-2-position (cocoa butter) is absorbed faster than asymmetrical TAGs with saturated fatty acids in the i -2-position, leading to higher postprandial lipemia and activated factor Vila levels (67). 

To date, lipase-catalyzed interesterihcation has been apphed almost exclusively to the production of value-added products. One of the best examples is the manufacture of cocoa-butter-type TAGs. The potential of i -l,3-specihc lipases for production of cocoa butter substitutes relies on enzyme-catalyzed tra i-esterihcation or acidolysis of palm oil with tristearin or stearic acid, respectively. 

Cocoa butter is the most expensive constituent of chocolate formulations as well as an extremely important component. It is composed predominantly (>75%) of symmetrical triacylglycerols with oleic acid in the 2-position (1). Approximately 20% of triacylglycerols are hquid at room temperature, and cocoa butter has a melting range of 32-35°C and softens around 30-32°C. This is essential to the functionahty of cocoa butter in its applications. It contains only trace amounts of the unsymmetrical triacylglycerols (PPO, PSO, and SSO). (P = palmitic acid, O = oleic acid, and S = stearic acid the order of letters indicates the position of the acids in the triacylglycerols molecule.)... 

Theobroma Oil, Cacao butter cocoa butter From roasted seeds of Theobroma cacao L., Sterculiaceae. Constit, Chiefly glycerides of stearic, palmitic, oleic, ara-chidic, and linoleic acids. 

Group 2 A group of seed oils of some tropical trees, such as cocoa or shea butter, and also pahn oil that is produced from the pericarp, not from the seed. These oils are characterized by their high content of palmitic and stearic acids, and are solid at ambient temperature in temperate climates (Table 11.4). 

Cocoa butter substitutes are also examples of sTAG and can be successfully synthesized by enzymes. One such substitute is synthesized from palm oil and stearic acid by sn-1,3 selective lipases from Candida antarctica, Pseudomonas sp. 

Cocoa butter (CB) is a highly valued ingredient primarily used in the confectionery industry due to its specific physical and chemical properties. CB is solid at room temperature (below 25 °C), and liquid at body temperature (—37 °C) [43], Furthermore, the predominant presence of symmetrical TAG, about 90 % of the TAG species in CB, is mainly responsible for the functionality of this fat [44], The major FAs of cocoa butter are palmitic acid (Cl6) 25-33.7 %, stearic acid (C18 0) 33.7-40.2 %, oleic acid (C18 l) 26.3-35 % and linoleic acid... 

One of the most abundant SFA in many common foods (dairy, meat, palm and coconut oil) is palmitic acid (PA, 16 0). The amoimt of PA is the highest in palm oil (around 50%), but significant amounts of PA (25-26%) can also be foimd in butter, chicken fat, lard, beef and lamb fat, as well as in cocoa butter. Even olive oil, which is one of basic components of the healthy Mediterranean diet contains around 16% of PA [6]. Fiulhermore, PA is present in human milk with 20-25% of total fats. Overall, PA and stearic acid (18 0) are the most common dietary SFA and therefore they are also the major SFA in hiunan plasma and tissues. Their concentration in serum/plasma phospholipids and cholesterol esters reflect dietary high fat intake. 

Despite popular impression stearic acid (18 0) is less common than palmitic. It is present in most vegetable fats though a significant component in only a few such as the vegetable butters cocoa butter (30-36%, Section 3.3.7), Illipe or Borneo tallow (46%, Section 3.3.17) and Shea butter (44%, Section 3.3.32). Present in most animal fats, it is a major component in the tallow of ruminant animals (5-30%, Section 3.4.2). 

Di- and tri-acid triglycerides with one or two unsaturated chains have more complex phase behaviour. Cocoa butter which is dominated by triglycerides with oleic acid in the 2-position and palmitic and stearic acid in the 1- and 3-positions, exhibits six crystal forms. Transitions into the most stable form causes so-called blooming of chocolate. An interesting study of the polymorphism and the... 

An example of the value of this technique is to be found in the upgrading of palm mid fraction in terms of its potential as a cocoa butter substitute. Before interesterification this contains POP (58%), POS (13%) and SOS (2%). These values are changed to 19, 32 and 13% after interesterification with stearic acid in the presence of A. niger lipase which is 1,3-specific. 

For example, the emulsion aerosol where stearic acid is used as emulsifier could be prepared by the method described below All ingredients, stearic acid 9.5%, cocoa butter 2.0%, Cetyl alcohol 1.0%, glycerol 2.0%, potassium hydroxide 1.7%, sodium hydroxide 3.0%, water 83.5%, are heated and emulsified to obtain OAV emulsion Drug could be added into the emulsion, oil phase, or water phase, as the case may be. The final aerosol product contains 5% propellants and 95% emulsion described above. 

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