Waxes, fats and oils

and waxes are common constituents of plants and usually consist of terpene hydrocarbons and their derivatives or alcohols, acids, and esters (Parker, 1969 Streibl and Herout, 1969 Wollrab and Streibl, 1969). 

FIGURE 3.11 Representation of protein structure showing (a) atomic and (b) spatial arrangement of the helix. (From Roberts, J.D. and Caserio, M.C., Basic Principles of Organic Chemistry, Benjamin Book Publishers, Inc., New York, 1964.) 

Tobacco mosaic virus 41,000,000 Infected tobacco plants 

Source Roberts, J.D. and Caserio, M.C., Basic Principles of Organic  

However, oils occur in much greater concentrations in fruits and seeds. The so-called essential oils are usually sweet, or aromatic smelling organic compounds which may also contain sulfur and nitrogen in addition to the usual carbon and hydrogen. These oils are often of the terpene class with the general formula (C5Hg) , where n 1, or may be compound types similar to camphor or other oxidation products associated with the basic terpene structure. 

Archaeological Chemistry, Second Edition By Zvi Goffer Copyright 2007 John Wiley Sons, Inc. 

TABLE 78 Main Fatty Acids in Common Oils and Fats 

Lipid Fatty acid components Number of carbon atoms in fatty acid chain 

Polymers are substances whose molecules are very large, formed by the combination of many small and simpler molecules usually referred to as monomers. The chemical reaction by which single and relatively small monomers react with each other to form polymers is known as polymerization (Young and Loveii 1991). Polymers may be of natural origin or, since the twentieth century, synthesized by humans. Natural polymers, usually referred to as biopolymers, are made by living organisms. Common examples of biopolymers are cellulose, a carbohydrate made only by plants (see Textbox 53) collagen, a protein made solely by animals (see Textbox 61), and the nucleic acid DNA, which is made by both plants and animals (see Textbox 64). 

Proteins, the main constituents of the animals body, are polypeptides, biopolymers consisting of many amino acid molecules (the monomers) combined together (see Chapter 11) collagen, for example, the main component of animal skin, is a complex protein consisting of many molecules of amino acids combined together into polypeptide chains (see Fig. 71). Polysaccharides, the essential constituents of plants, also consist of many monosaccharide molecules combined together. Cellulose, the most abundant biological material on earth, which makes up most of the structural 

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C, b.p. 81"C. Manufactured by the reduction of benzene with hydrogen in the presence of a nickel catalyst and recovered from natural gase.s. It is inflammable. Used as an intermediate in the preparation of nylon [6] and [66] via caprolactam and as a solvent for oils, fats and waxes, and also as a paint remover. For stereochemistry of cyclohexane see conformation. U.S. production 1980 1 megatonne. 

Other uses of HCI are legion and range from the purification of fine silica for the ceramics industry, and the refining of oils, fats and waxes, to the manufacture of chloroprene mbbers, PVC plastics, industrial solvents and organic intermediates, the production of viscose rayon yam and staple fibre, and the wet processing of textiles (where hydrochloric acid is used as a sour to neutralize residual alkali and remove metallic and other impurities). 

Lewkowitsch, J. (1922), Chemical Technology and Analysis of Oils, Fats, and Waxes, Macmillan, London. 

Serpico, M. and R. White (2000b), Oil, fat and wax, in Nicholson, P. T. and I. Shaw, Ancient Egyptian Materials and Technology, Cambridge Univ. Press, Cambridge, UK, pp. 390-429. 

Uses Solvent for paints, varnishes, nitrocellulose lacquers, oils, fats, and waxes denaturant for ethyl alcohol in organic synthesis. 

Hexanone is not currently manufactured, processed, or used for commercial purposes in the United States (EPA 1987b). 2-Hexanone had been used as a solvent for many materials, primarily in the lacquer industry as a solvent for lacquers and varnish removers. It had also been used as a solvent for ink thinners, resins, oils, fats, and waxes. 2-Hexanone had also been used as an intermediate in the synthesis of organic chemicals (ACGIH 1986 HSDB 1989). 

Other extraction procedures are used for determining (i) oils, fats and waxes (ii) fibre, lignin, cellulose, nitrogen-free extract and starch (iii) in vitro... 

The species we have dealt with is winter rape Brassica napus L.). See comments in Chapter 4, Oils, fats and waxes, and the reference to Hughes (1969). 

Hydrocarbon oxidation may also be considered a free radical chain-type reaction. At elevated temperatures, hydrocarbon free radicals (R) are formed which react with oxygen lo form peroxy radicals (R(X These, in turn, take up a hydrogen atom from the hydrocarbon to form a hydroperoxide (ROOH) and another hydrocarbon free radical. The cycle repeals itself with the addition of oxygen. The unstable hydroperoxides remaining are the major points for degradation and lead to rancidity and color development in oils, fats, and waxes decomposition and gum formation in gasolines sludging in lubricants and breakdown of plastics and rubber products. Antioxidants, such as amines and phenols, are often introduced into hydrocarbon systems in order lo prevent this free radical oxidation sequence. 

Ackman, R.G. (1983). Marine lipids. Fats for the future. In Proceedings of the International Conference on Oils, Fats and Waxes , pp.1-15. Duromark Publishing, Auckland. 

AOCS (American Oil Chemists Society) (1997) Physical and Chemical Characteristics of Oils, Fats and Waxes, 2nd edn. American Oil Chemists Society. 

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