Fat isolation

Van der Wei, H. and De Jong, K. 1967. Occadecadienoic acids in butter fat. II. Identification of some nonconjugated fatty acids. Fette Seifen. Anstrichm. 64, 277-279. Weihrauch, J. L., Brewington, C. R. and Schwartz, D. P. 1974. Trace components in milk fat Isolation and identification of oxofatty acids. Lipids 9, 883-890. 

The acetone-soluble fraction was known to contain a large percentage of free fatty acids in addition to the fatty esters. Some of these fatty acids were found by Anderson to be of a type hitherto unknown. In common with the waxes, this fat did not contain any free glycerides. Alkaline hydrolysis of the fat derived from human strain bacilli yielded a water-soluble carbohydrate. This was identified as trehalose by isolation of the crystalline sugar. Corresponding fats isolated from the bovine and avian strains of bacilli were examined. The presence of glycerol could not be detected nor could the carbohydrate components be identified. 

The semi-solid fat, isolated by expelling and extraction, is used directly as a component of vegetable shortenings. It can be converted to a vegetable butter either by partial hydrogenation or fractionation. The meal is toxic to livestock. 

The induction period for formation of PBN spin adducts in milk fat, isolated from butter, is shown in Figure S. The course of radical formation resemblances that typically observed in other accelerated oxidation tests, such as Rancimat and Oxidograph methods. This ESR procedure has the advantage of milder conditions compared to other methods, combined with a short assay time. 

Figure A3.13.1. Schematic energy level diagram and relationship between mtemiolecular (collisional or radiative) and intramolecular energy transfer between states of isolated molecules. The fat horizontal bars indicate diin energy shells of nearly degenerate states.

Natural products that contain carbon-carbon triple bonds are numerous Two examples are tariric acid from the seed fat of a Guatemalan plant and cicutoxin a poi sonous substance isolated from water hemlock... 

Protein-Based Substitutes. Several plant and animal-based proteins have been used in processed meat products to increase yields, reduce reformulation costs, enhance specific functional properties, and decrease fat content. Examples of these protein additives are wheat flour, wheat gluten, soy flour, soy protein concentrate, soy protein isolate, textured soy protein, cottonseed flour, oat flour, com germ meal, nonfat dry milk, caseinates, whey proteins, surimi, blood plasma, and egg proteins. Most of these protein ingredients can be included in cooked sausages with a maximum level allowed up to 3.5% of the formulation, except soy protein isolate and caseinates are restricted to 2% (44). 

The quaHty, ie, level of impurities, of the fats and oils used in the manufacture of soap is important in the production of commercial products. Fats and oils are isolated from various animal and vegetable sources and contain different intrinsic impurities. These impurities may include hydrolysis products of the triglyceride, eg, fatty acid and mono/diglycerides proteinaceous materials and particulate dirt, eg, bone meal and various vitamins, pigments, phosphatides, and sterols, ie, cholesterol and tocopherol as weU as less descript odor and color bodies. These impurities affect the physical properties such as odor and color of the fats and oils and can cause additional degradation of the fats and oils upon storage. For commercial soaps, it is desirable to keep these impurities at the absolute minimum for both storage stabiHty and finished product quaHty considerations. 

It can be found in animal tissues (1), in vegetables and fmit (2,3), or in spring water (4), and has also been identified in meteorites (5). It is formed in alcohohc fermentation (6) and in the chemical and biochemical oxidation of fats. Succinic acid is present in amber (7) Succinuni) and can be obtained by distillation, by which method it was first isolated by Georgius Agricola in 1550. 

Although vegetable oils and animals fats were commonly used in ancient times, most higher acids were not known until the beginning of the nineteenth century. Then the nature of the naturally occurring 18-carbon fatty acids was estabHshed, and hundreds of long-chain fatty acids have been isolated from natural sources and characterized. 

Myristic acid occurs as a glyceride in many vegetable fats and oils, in particular in coconut oil,i its isolation from which involves separation from homologs by fractional distillation of the acids or their esters. The trimyristin obtained from nutmegs 2 (p. 100) or from the seeds of Virola venezuelensis forms the most suitable source. 

N. L. Vauquelin isolated the Hrst organic P compound (lethicin) from brain fat it was characterized as a phospholipid by Gobbley in 18.50. 

Gel permeation ehromatography (GPC)/normal-phase HPLC was used by Brown-Thomas et al. (35) to determine fat-soluble vitamins in standard referenee material (SRM) samples of a fortified eoeonut oil (SRM 1563) and a eod liver oil (SRM 1588). The on-line GPC/normal-phase proeedure eliminated the long and laborious extraetion proeedure of isolating vitamins from the oil matrix. In faet, the GPC step permits the elimination of the lipid materials prior to the HPLC analysis. The HPLC eolumns used for the vitamin determinations were a 10 p.m polystyrene/divinylbenzene gel eolumn and a semipreparative aminoeyano eolumn, with hexane, methylene ehloride and methyl tert-butyl ether being employed as solvent. 

In biological pathways, dehydrations rarely occur with isolated alcohols but instead normally take place on substrates in which the -OH is positioned two carbons away from a carbonyl group. In the biosynthesis of fats, for instance, /3-hydroxybutyry) ACP is converted by dehydration to tram-crotonyl ACP, where ACP is an abbreviation for acyl carrier protein. We ll see the reason for this requirement in Section 11.10. 

Lipids are naturally occurring organic molecules that have limited solubility in water and can be isolated from organisms by extraction with nonpolar organic solvents. Fats, oils, waxes, many vitamins and hormones, and most nonprotein cell-meznbrane components are examples. Note that this definition differs from the sort used for carbohydrates and proteins in that lipids are defined by a physical property (solubility) rather than by structure. Of the many kinds of lipids, we ll be concerned in this chapter only with a few triacvlglycerols, eicosanoids, terpenoids, and steroids. 

Lipid (Section 27.1) A naturally occurring substance isolated from cells and tissues by extraction with a nonpolar solvent. Lipids belong to many different structural classes, including fats, terpenes, prostaglandins, and steroids. 

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