Food Lipids: Chemistry, Nutrition, and Biotechnology

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tools for using genetic transformation as a means to study the process and control of lipid biosynthesis in plants. In turn, this will provide greater understanding of how to manipulate fatty acid composition in plant storage lipids for specific purposes or end uses. It is also well known that the arrangement or distribution of fatty acyl groups along the glycerol backbone of triacylglycerols (i.e., profile of molecular species of triacylglycerols) also impacts greatly on the composite physiochemical or nutritional properties of a particular lipid (33,34). Lipids of similar fatty acid composition may have markedly different physiochemical properties because of how the fatty acids are distributed. The origins of positional distribution of fatty acids lie in triacylglycerol assembly in plants, an area in which definitive research is barely a decade old (20,35). However, a working knowledge of how triacylglycerols are specifically assembled in different species will be paramount to identifying strategies by which to modify the process in vivo and to direct triacylglycerol assembly in a manner designed to improve the functional properties of the lipid resource in foods. Section V explores this phase of lipid biosynthesis in detail. III. FATTY ACID BIOSYNTHESIS A. Comparative Biochemistry of Fatty Acid Synthetase Systems 1. Historical Perspective It has been about 50 years since fatty acid synthesis was first demonstrated in cellfree extracts (36). Some of the earliest studies revealed the essential features of fatty acid biosynthesis: it required ATP, NADPH, CO2 ( ), CoA, Mn 2� � HCO3 , acetate, and source of heat-labile (FAS enzymes) and heat-stable (ultimately determined to be acyl carrier protein) proteinaceous factors isolated from the organism of interest. Slowly, each discrete, protein-associated unit activity of the type I and II fatty acid synthetase (FAS) systems was identified. Table 3 gives some of the seminal citations (37) that formalized the identification of these components and lists the unit activities (38–55). Even though virtually all the FAS enzymes, and corresponding steps in fatty acid biosynthesis, had been isolated and identified by the early 1980s, discoveries and challenges to dogmatic views regarding this intensely researched area of primary metabolism have continued. A case in point is the discovery and elucidation over the last decade of an enzyme isoform, now believed to cause the initial condensation reaction in type II FAS systems in plants and bacteria (43,44,56), and the repeated speculation that there is another condensing enzyme yet to be discovered (44,56–59). In contrast to the wealth of history of research on fatty acid biosynthesis, definitive studies on triacylglycerol assembly and control of this process extend barely a decade into the past (15,20,35). The study of both fatty acid biosynthesis and assembly into triacylglycerols (and other glycerolipids) is essentially research in enzymology. The advent of genetic manipulation of organisms has made progress in both these areas of lipid synthesis extremely rapid since about 1990. While the theme of this chapter is founded on the characteristics of the individual enzymes involved in storage lipid biosynthesis, the superseding objective is to convey how these individual steps are coordinated as part of this overall process. Copyright 2002 by Marcel Dekker, Inc. All Rights Reserved.
2. Basic Features The functional units of FAS are essentially identical for all living organisms (10). These functional units will be designated by the acronyms appearing in Table 3, in boldface type, for the balance of this chapter. The distinction between FAS in various classes of organisms (plants, animals, microbes) lies in compartmentation and organizational structure of FAS, as well in as subtle differences in reaction selectivities and activities of the functional units [viz., enzymes and acyl carrier protein (ACP)] of FAS. These subtle differences account for the markedly different patterns and profiles of fatty acid biosynthesis in various classes of organisms. Because fatty acid biosynthesis is energy intensive, it is subject to metabolic regulation and requires insulation from competing pathways or premature termination. Fatty acid biosynthesis is metabolically channeled in plants by virtue of an ‘‘ACP track’’ in the plastidic compartment, where the lengthening acyl chain remains covalently linked to ACP (or to the condensing enzyme) until completely synthesized. The putative product of FAS systems is palmitic acid in animals, palmitoyl- CoA in yeasts and fungi, and palmitoyl-ACP in plants and lower bacteria. Some organisms, especially oil-bearing plants, have the important capability of premature termination of fatty acids biosynthesis, giving rise to fatty acids of shorter chain lengths as the principal products (e.g., oils rich in lauric acid). The synthesized fatty acids are then exported to a ‘‘CoA track’’ in the endoplasmic reticulum, which serves to channel fatty acyl residues through subsequent and characteristic modification processes of oxygenation, elongation, and desaturation. Finally the fatty acids are assembled into storage and functional glycerolipids, principally in the same cellular compartment. 3. Organization and Localization FAS systems can be classified as type I or II systems. [Historically, type III systems, or palmitate elongases, have been used to classify elongation activities yielding acyl chains longer than that of palmitate (10)]. Type I FAS systems are characterized by multifunctional protein domains, whereas type II FAS systems are characterized by dissociable proteins, each having a specific, unit activity of the FAS system. Eukaryotes (and some higher prokaryotes, such as Mycobacterium and Corynebacterium) have type I FAS systems, as characterized from liver, adipose, and mammary and uropygial gland tissues, where the full complement of FAS activities is located on a single polypeptide domain of about 240 kDa (9). This single polypeptide has three functional subdomains, one possessing substrate entry and condensation activities of ACAT, MCAT, and KAS; the second possessing ACP and reducing activities of KHAD, EAR, and KAR; and the third, or C-terminal domain, having TE.* In situ, these FAS systems exist as homodimers where the substrate entry/condensation subdomain of one monomer channels the lengthening acyl chain to the reducing subdomain of the other monomer (i.e., functional division of dimer is not identical to the subunit division of the dimer). Organizationally, another type I FAS system, such as in yeast, fungi and some higher bacteria, is characterized by a heteromer of two protein domains (�6�6), each possessing a portion of the total FAS activities (9,60,61). The �-chain has ACP, *For abbreviations of enzyme activities, see Table 3. Copyright 2002 by Marcel Dekker, Inc. All Rights Reserved.
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TM Food Lipids Chemistry, Nutrition
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FOOD SCIENCE AND TECHNOLOGY A Serie
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37. Omega-3 Fatty Acids in Health a
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90. Dairy Technology: Principles of
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Preface to the Second Edition Reade
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Preface to the First Edition There
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Contents Preface to the Second Edit
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20. Dietary Fats and Coronary Heart
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J. Bruce German Department of Food
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1 Nomenclature and Classification o
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described as 2-methyl-3-phytyl-1,4-
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Table 3 A Summary of Sequence Prior
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Table 5 Systematic, Common, and Sho
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saturation of EFA occurs (primarily
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Figure 5 Prostaglandin metabolites
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Figure 7 Prostanoic acid and prosta
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Figure 9 Eicosenoid isomers in part
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Figure 10 Nomenclature of cyclic fa
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Figure 13 Hydroxy fatty acid struct
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Figure 15 Furanoid fatty acid struc
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Table 7 Short Abbreviations for Som
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Figure 20 Steroid nomenclature. rep
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Figure 22 Cholesterol oxidation pro
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E. Phosphoglycerides (Phospholipids
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Figure 26 Glyceroglycolipid structu
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Figure 28 Structures of some vitami
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6. IUPAC. Nomenclature of Organic C
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2 Chemistry and Function of Phospho
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variant [1]. Phosphonolipids are ma
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nonelectrolytes, however, the perme
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pensations in that enthalpy lost by
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Table 3 Membrane Deterioration in A
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erols to generate semisolid or plas
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The interaction of phospholipids wi
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fatty acid occurs when Fe 3� at t
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4. M. C. Blok, L. L. M. van Deenen,
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47. N. Markova, E. Sparr, L. Wadso,
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87. R. J. Hsieh. Contribution of li
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3 Lipid-Based Emulsions and Emulsif
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may be composed of surface-active c
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2. Cloud Point When a surfactant so
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HLB=7� � (hydrophilic group num
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sion is known as the phase inversio
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strongly with each other rather tha
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� = � (1 � 2.5�) (3) 0 wher
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Figure 8 Biopolymer molecules or ag
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divide homogenization into two cate
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2� �P 1 = (4) r where � is th
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flow rate, decreasing the size of t
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sion be particularly small, it is u
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2. Electrostatic Interactions Elect
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profile of interdroplet pair potent
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Figure 12 Mechanisms of emulsion in
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[Eq. (9)], but at high droplet conc
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alteration in the system’s compos
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Food emulsions always contain dropl
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creaming and sedimentation in emuls
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Foams (E. Dickinson and G. Stainsby
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4 The Chemistry of Waxes and Sterol
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Shrinkage and flash point are two f
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lowing discussion on chemical analy
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violet chromophore. Application of
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Figure 1 Examples of naturally occu
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Scheme 1 Synthesis of mevalonic aci
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Scheme 3 Synthesis of farnesyl pyro
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Scheme 6 Biosynthesis of cholestero
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educe the risk of coronary heart di
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of cholesterol to bile acids (Schem
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Scheme 10 Metabolic alterations of
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sample preparation is usually emplo
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at levels of 1-100 �g per compone
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30. H. W. Chen, A. A. Kandutsch, an
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Biologically Significant Steroids (
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5 Extraction and Analysis of Lipids
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preparing nutritional labeling mate
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polar solvents, such as alkanols, f
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a ternary system consisting of chlo
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lipids from meat or hydrolytic prod
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perature under vacuum. Acid hydroly
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IV. ANALYSIS OF LIPID EXTRACTS Lipi
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ments, etc.) primarily involves chr
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2. Gas Chromatography The GC (or GL
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4. Supercritical Fluid Chromatograp
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Table 3 Solvent Systems that Could
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sibility of determining all compone
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the isolated trans band is another
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ionized molecule has the highest m/
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3. W. R. Bloor. Outline of a classi
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45. Association of Official Analyti
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90. M. N. Vaghela and A. Kilara. A
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132. C. G. Walton, W. M. N. Ratnaya
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6 Methods for trans Fatty Acid Anal
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where A = abc (1) 1 A = absorbance
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methyl elaidate weight equivalents
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method was modified by inclusion of
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may be packed or bound to a column,
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Figure 4 The C-18 region of the gas
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Table 2 Response Factors of Unsatur
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Figure 5 Separation of the phenacyl
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B. Gas Chromatography/IR Spectrosco
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Figure 7 Expanded IR spectral range
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CFAMs before converting them to the
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Figure 8 GC-EIMS chromatographic da
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flame ionization detection. The fat
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levels in excess of 50% of the tota
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22. A. Huang and D. Firestone. Dete
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59. E. G. Perkins and C. Smick. Oct
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97. Association of Official Analyti
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136. J. J. Myer and A. Kukis. Elect
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7 Chemistry of Frying Oils KATHLEEN
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Table 1 Effects of Physical and Che
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Figure 3 Oxidation reactions in fry
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or intermittent frying, oil filtrat
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for the ultimate criteria to evalua
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triacylglycerol polymers, and triac
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100 compounds identified in hydroge
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5. J. Pokorny. Flavor chemistry of
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50. Anonymous. Recommendations of t
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8 Recovery, Refining, Converting, a
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Figure 1 Depiction of hard screw pr
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Figure 2 Depiction of prepress solv
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Seed containing more than the criti
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Figure 5 Steps in processing soybea
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specification of 50% protein is met
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tent of prepress cake is 15-18%, an
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in successive passes through the be
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Figure 10 Additional commonly used
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that follow the DT. Drying at norma
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B. Extraction of Oil-Bearing Fruits
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1. Wet Rendering Wet rendering is t
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Figure 15 Process flow sheet for de
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Table 2 Properties of Some Crude an
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Figure 16 Process flow sheet for al
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Figure 17 Process flow sheet for va
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for problematic high wax contents (
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Figure 19 Oil processing facilities
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Figure 20 Depiction of physical ref
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4-7�C, and then to tanks with slo
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Figure 21 Hydrogenation reaction me
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ond, which may form in its original
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Figure 24 Plasticization of margari
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Figure 25 Equipment used in expande
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selectivity, others claim success i
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48. E. J. Campbell. Sunflower oil.
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9 Crystallization and Polymorphism
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Generally, it is accepted that both
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Figure 2 A point lattice. (Adapted
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structure.... The term ‘fat’ us
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Figure 6 Schematic representation o
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Figure 8 Polymorphic transitions of
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where A = B = C and all are saturat
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LMF was found to facilitate the tra
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Table 3 Nomenclature and Melting Po
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Other mixed-fat systems have been s
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Figure 12 Proposed intermediate str
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17. K. Larsson. The crystal structu
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59. G. G. Jewell. Vegetable fats. I
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10 Chemical Interesterification of
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however, since monoacylglycerols an
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D. The ‘‘Real’’ Catalyst Th
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Figure 3 Proposed reaction mechanis
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Figure 5 Kinetics of interesterific
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Table 1 Theoretical Triacylglycerol
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Cast et al. [55] demonstrated the r
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Solid: Liquid: SSS, 33.3% OOO, 8.3%
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Figure 11 Changes in the fatty acid
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fication and blending on butterfat-
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influence of interesterification on
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B. Margarines In the manufacture of
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Figure 16 Proportion of soild fat o
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Tautorus and McCurdy [102] demonstr
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ACKNOWLEDGMENTS The authors acknowl
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54. A. Kuksis, M. J. McCarthy, and
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101. S. Zalewski and A. M. Gaddis.
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11 Lipid Oxidation of Edible Oil DA
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Figure 1 Molecular orbital of tripl
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Figure 3 Singlet oxygen formation b
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tween substrate and triplet oxygen
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Figure 8 Conjugated and nonconjugat
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Figure 11 Conjugated hydroperoxide
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etween the oxygen and the oxygen of
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cadienal, trans,trans-2,4-decadiena
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Figure 14 Mechanism for the formati
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Copyright 2002 by Marcel Dekker, In
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Figure 18 Formation and reactions o
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Figure 19 Effect of 0, 0.25, 0.5, a
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Figure 21 Singlet oxygen quenching
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10. E. N. Frankel. Chemistry of aut
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52. A. L. Callison. Singlet oxygen
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12 Lipid Oxidation of Muscle Foods
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A. Initiation The direct reaction o
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undles), and endomysia (sheaths of
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sosomes, etc. A comparison of the l
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dative stability, comparisons betwe
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5. Hydrolysis of Lipids and Associa
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of iron from the heme pocket by coo
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Membrane systems that reduce iron c
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phases of storage [51,187,188]. In
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4. Glutathione While the traditiona
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G. Mathematical Modeling The pathwa
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with this chemical, treated salmon
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multicomponent alternatives [304,30
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and its extent was related to inten
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esponded similarly to vacuum packag
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31. M. L. Greaser, R. G. Cassens, W
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72. J. S. Elmore, D. S. Mottram, M.
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112. J. Kanner, H. Mendel, and P. B
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154. M. B. Korycka-Dahl and T. Rich
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193. P. Akhtar, J. I. Gray, T. H. C
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230. B. Bjerkeng and G. Johnsen. Fr
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271. C.-J. Huang, and M.-L. Fwu. De
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313. M. G. Mast and J. H. MacNeil.
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353. H. A. Ghanbari, W. B. Wheeler,
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13 Fatty Acid Oxidation in Plant Ti
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1. Fatty Acid Activation Prior to d
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L.) leaf peroxisomes exhibits highe
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Figure 2 The glyoxylate cycle in gl
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C. �-Oxidation of Specific Fatty
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cotyledons and partially purified.
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Catabolism of heptanoyl CoA as well
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Figure 6 Peroxisome catabolism of m
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onstrated that �-oxidations requi
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that the member of the enzyme famil
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Plant oxylipin pathway, also named
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Figure 9 Proposed scheme for lipoxy
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oleic acid. These results suggest t
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of the seed pod reversed senescnece
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Figure 11 ‘‘Heterolytic’’-t
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Since 1971, when this physiologic r
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Table 1 Physiological Effects of Ja
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erides, although PUFAs in both form
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9-hydroperoxides and did not attack
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aerial parts of plants, constitutes
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32. J. B. Ohlrogge and V. S. Eccles
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74. L. J. Morris. The mechanism of
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115. B. A. Vick. Oxygenated fatty a
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153. T. K. Peterman and J. N. Siedo
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193. B. A. Stelmach, A. Müller, P.
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230. M. Hamberg, C. A. Herman, and
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14 Methods for Measuring Oxidative
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ated fatty acids during oxidation (
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Several other chemical methods have
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Figure 3 Relationship between perox
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distillate. In case of the distilla
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and ketones. This ion is formed fro
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(Fig. 9), foaming, color, viscosity
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Yen and Duh [69] and Chen and Ho [7
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Figure 10 1 H Nuclear magnetic reso
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to Marquez-Ruiz et al. [93], who us
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35. F. Shahidi, J. Yun, L.J. Rubin,
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77. H. Saito and K. Nakamura. Appli
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15 Antioxidants DAVID W. REISCHE Th
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Hydroperoxide degradation leads to
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e cyclical, with regeneration of th
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A. Synthetic Antioxidants Synthetic
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Propyl gallate (PG) 212.20 White cr
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4. 6-Ethoxy-1,2-dihydro-2,2,4-trime
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Figure 3 Structures of tocopherols
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Figure 4 Structures of ascorbic aci
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4. Enzymatic Antioxidants Glucose o
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would be imprudent to discount any
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droxycoumarin (scopoletin), and hyd
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Figure 7 Structures of sesame antio
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8. G. Minotti. Sources and role of
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50. K. Shimada, H. Muta, Y. Nakamur
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16 Antioxidant Mechanisms ERIC A. D
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For instance, the hydrogen of the h
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Figure 2 Mechanism by which one phe
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Figure 4 Formation of �-tocophero
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Figure 6 Formation of an epoxyquino
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gallate. The antioxidant mechanism
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Figure 8 Products formed from the o
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in food systems, transition metals
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An intersystem energy transfer occu
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V. ALTERATIONS IN LIPID OXIDATION B
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VII. ANTIOXIDANT INTERACTIONS Biolo
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26. J. Kanner, J. B. German, and J.
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68. J. Kanner, F. Sofer, S. Harel,
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17 Fats and Oils in Human Health DA
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Table 1 Classification of LDL Parti
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stearic) had been incorporated by i
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studies contains equal amounts (40-
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Table 5 Influence of 25% Caloric Re
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26. L. D. Cowan, D. L. O’Connell,
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fatty acid margarine on serum lipid
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nutrition examination survey. I. Ep
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18 Unsaturated Fatty Acids STEVEN M
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Figure 1 A generalized scheme for h
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Plant fatty acids provide a seminal
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plants [27]. However, the requireme
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The reciprocal response of the �6
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fatty acids and a dynamic system fo
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production of commercially viable o
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acids synthesized de novo, primaril
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Figure 4 The cis and trans configur
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VI. SYNTHESIS AND ABUNDANCE OF PUFA
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of eicosanoids. It is present in al
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usual NMIFA structures with potenti
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10. S. P. Baykousheva, D. L. Luthri
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47. M. J. T. Alaniz, I. N. T. d. Go
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86. R. J. Henderson and D. R. Toche
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19 Dietary Fats, Eicosanoids, and t
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synthesize EPA from linolenic acid
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Figure 2 Immune responses as a func
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done predominantly in rodent specie
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guinea pigs showed increased immune
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of energy from fat. Feeding the low
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14. P. Purasiri, A. Murray, S. Rich
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20 Dietary Fats and Coronary Heart
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(HDLs). Each class has its own char
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70% of the total amount of choleste
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McGandy and coworkers [8] have care
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Figure 4 Effects of myristic and pa
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3. Polyunsaturated Fatty Acids Poly
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Figure 8 Effects of a mixture of sa
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chemoattractant protein-1 (MCP-1),
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Figure 11 In vitro LDL oxidation. F
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Table 4 Fatty Acid Composition of a
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Figure 12 Processes involved in thr
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as compared with a diet rich in but
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from cardiovascular disease [73,74]
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Figure 16 Schematic representation
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aggregation tendency induced by som
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35. D. R. Janero. Malondialdehyde a
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68. B. J. Burrl, R. M. Dougherty, D
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21 Conjugated Linoleic Acids: Nutri
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method that works optimally in all
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adipose tissue contained two major
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providing rats with 0.5% and 1% CLA
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with the control group. Interesting
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feeding. These findings suggest tha
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In contrast to the antioxidative pr
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esponsible, at least in part, for t
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Yamasaki et al. studied CLA and ant
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17. J. K. G. Kramer, P. W. Parodi,
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55. C. Ip, S. F. Chin, J. A. Scimec
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90. J. S. Munday, K. G. Thompson, a
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126. J. Singh, R. Hamid, and B. S.
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22 Dietary Fats and Obesity DOROTHY
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For example, some have reported tha
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the fat component and the other hal
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shows that there is a negative corr
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C. Influence of Dietary Fat on Fatt
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Figure 1 Signal transduction cascad
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mals indicate that high-fat feeding
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processes. Numerous studies provide
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monier (252) suggested that in cert
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4. National Task Force on Obesity.
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46. F. Lucas, K. Ackroff, and A. Sc
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90. D. Mela. Sensory preference for
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133. D. R. Romsos and G. A. Leveill
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169. T. Ide, H. Kobayashi, L. Ashak
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207. A. B. Awad and E. A. Zepp. Alt
Page 711 and 712:
246. Y. B. Kim, R. Nakajima, T. Mat
Page 713 and 714:
23 Lipid-Based Synthetic Fat Substi
Page 715 and 716:
operations, and in theory, can repl
Page 717 and 718:
Table 3 Types of Lipid-Based Fat Su
Page 719 and 720:
Figure 1 Structure of sucrose polye
Page 721 and 722:
Figure 3 Synthetic scheme for olest
Page 723 and 724:
Figure 5 Structure of sorbitol poly
Page 725 and 726:
Figure 8 Structure of raffinose pol
Page 727 and 728:
Figure 11 Structure of methyl galac
Page 729 and 730:
Table 4 Some Properties of Sucrose
Page 731 and 732:
Figure 15 Structure of trialkoxytri
Page 733 and 734:
Figure 19 Structure of polysiloxane
Page 735 and 736:
inversely related to the degree of
Page 737 and 738:
Table 8 Some Nutritional Uses of No
Page 739 and 740:
genetic assay in Chinese hamster ov
Page 741 and 742:
IX. PERSPECTIVES With the approval
Page 743 and 744:
30. L. Osipow, F. D. Snell, D. Marr
Page 745 and 746:
72. K. W. Miller and P. H. Long. A
Page 747 and 748:
24 Food Applications of Lipids FRAN
Page 749 and 750:
Table 3 Typical Fatty Acid Composit
Page 751 and 752:
are significant differences in oil
Page 753 and 754:
Table 6 Production and Disappearanc
Page 755 and 756:
and margarine should be pronounced
Page 757 and 758:
Table 8 Approximate Fatty Acid Comp
Page 759 and 760:
egions of the world. In addition to
Page 761 and 762:
50-55% fat. Production figures for
Page 763 and 764:
utter with up to 5% of another fat
Page 765 and 766:
market with high overrun and good s
Page 767 and 768:
11. D. Hettinga. Butter. In: Bailey
Page 769 and 770:
25 Lipid Biotechnology KUMAR D. MUK
Page 771 and 772:
Table 1 Lipid Content and Levels of
Page 773 and 774:
as 80% lipids of which about 90% ar
Page 775 and 776:
Table 6 Wax Esters Formed by Acinet
Page 777 and 778:
Some other biosurfactants include e
Page 779 and 780:
Figure 6 Microbial production of hy
Page 781 and 782:
Figure 9 Microbial production of ke
Page 783 and 784:
Figure 12 Microbial production of k
Page 785 and 786:
Table 8 Specificity of Triacylglyce
Page 787 and 788:
Figure 16 Lipase-catalyzed transest
Page 789 and 790:
Figure 20 Preparation of structured
Page 791 and 792:
Figure 24 Preparation of monoacylgl
Page 793 and 794:
Fatty acid esters of polyols are us
Page 795 and 796:
Figure 29 Specificity constants in
Page 797 and 798:
Figure 31 Preparation of concentrat
Page 799 and 800:
Figure 35 Enrichment of very long c
Page 801 and 802:
B. Phospholipases Figure 38 shows t
Page 803 and 804:
Lysophosphatidic acid has been prep
Page 805 and 806:
Figure 41 Transesterification of ph
Page 807 and 808:
Figure 46 Enzymatic production of h
Page 809 and 810:
Figure 50 Hydration of linoleic aci
Page 811 and 812:
Figure 51 Principle of enzymatic de
Page 813 and 814:
13. E. Molina Grima, J. A. Sánchez
Page 815 and 816:
53. M. Powalla, S. Lang, and V. Wra
Page 817 and 818:
96. R. Schuch and K. D. Mukherjee.
Page 819 and 820:
138. K. D. Mukherjee and I. Kiewitt
Page 821 and 822:
179. U. T. Bornscheuer, H. Stamatis
Page 823 and 824:
222. H. Stamatis, V. Sereti, and F.
Page 825 and 826:
265. S. R. Moore and G. P. McNeill.
Page 827 and 828:
303. C. Virto, I. Svensson, and P.
Page 829 and 830:
343. E. Blee and F. Schuber. Regio-
Page 831 and 832:
26 Microbial Lipases JOHN D. WEETE
Page 833 and 834:
ation. Fungal lipases typically exi
Page 835 and 836:
of buffer A containing 1 M ammonium
Page 837 and 838:
without shaking for 30 minutes, whe
Page 839 and 840:
the C domain of the protein through
Page 841 and 842:
Figure 2 (Continued) Figure 3 Schem
Page 843 and 844:
on the substrate and presence or ab
Page 845 and 846:
Table 3 Selectivities of Multiple E
Page 847 and 848:
lanuginosa, C. antarctica B, Rhizop
Page 849 and 850:
10. C. T. Hou and T. M. Johnston. S
Page 851 and 852:
53. C. C. Akoh. Enzymatic synthesis
Page 853 and 854:
94. D. M. Lawson, A. M. Brzozowski,
Page 855 and 856:
135. B. K. Yang and J. P. Chen. Gel
Page 857 and 858:
27 Enzymatic Interesterification WE
Page 859 and 860:
esterification of butterfat at 40
Page 861 and 862:
also found to decrease the crystall
Page 863 and 864:
T c than animal fats. The T c for v
Page 865 and 866:
in the oxyanion hole is the amino a
Page 867 and 868:
of the interface as a measure of su
Page 869 and 870:
Figure 11 Catalytic mechanism for l
Page 871 and 872:
Figure 13 Triacylglycerol products
Page 873 and 874:
imization of interesterification, a
Page 875 and 876:
supports include high losses of act
Page 877 and 878:
is a thin layer located directly ne
Page 879 and 880:
volume per year. The volumetric act
Page 881 and 882: and removal of reactants and produc
Page 883 and 884: vinyl chloride. In a membrane such
Page 885 and 886: of the enzyme. Animal and plant lip
Page 887 and 888: esters as surface active agents dur
Page 889 and 890: 14. P. Kalo, H. Huotari, and M. Ant
Page 891 and 892: 57. F. Pabai, S. Kermasha, and A. M
Page 893 and 894: 94. J. Kurashige. Enzymatic convers
Page 895 and 896: 28 Structured Lipids CASIMIR C. AKO
Page 897 and 898: Figure 2 Structure of a physical mi
Page 899 and 900: 2. Medium Chain Fatty Acids and Tri
Page 901 and 902: Figure 4 Pathway for eicosanoid bio
Page 903 and 904: leukotrienes (hydroxy fatty acids a
Page 905 and 906: Figure 7 Structure of Benefat (bran
Page 907 and 908: cause of the huge capital investmen
Page 909 and 910: Figure 8 Reaction scheme showing ac
Page 911 and 912: alters the native conformation of t
Page 913 and 914: Table 6 Advantages of Enzymatic App
Page 915 and 916: Figure 13 Stereochemical configurat
Page 917 and 918: IV. NUTRITIONAL AND MEDICAL APPLICA
Page 919 and 920: Table 9 Factors That Affect Outlook
Page 921 and 922: 27. G. O. Burr and M. D. Burr. A ne
Page 923 and 924: 69. M. Reslow, P. Aldercreutz, and
Page 925 and 926: 113. C. J. Gollaher, E. S. Swenson,
Page 927 and 928: 29 Biosynthesis of Fatty Acids and
Page 929 and 930: olive (Olea europea), and avocado (
Page 931: Table 2 (Continued) Fatty acid a Sp
Page 935 and 936: Hydroxy-Acyl ACP dehydrase (Crotony
Page 937 and 938: Figure 1 Steps of fatty acid biosyn
Page 939 and 940: The three KAS isoforms are assigned
Page 941 and 942: chain length acyl-ACP residues, and
Page 943 and 944: 10-carbon and 14- to 16-carbon acyl
Page 945 and 946: In developing castor seed, BC and A
Page 947 and 948: (viz., seed, fruit) genes, and this
Page 949 and 950: Figure 4 Fatty acid modification re
Page 951 and 952: 12-MO, the cDNA for the enzyme has
Page 953 and 954: Table 5 Enzyme Activities Involved
Page 955 and 956: of reactivity is also supported by
Page 957 and 958: tems, PTAP is a likely candidate fo
Page 959 and 960: ifying 18:1 �9 and deacylating 18
Page 961 and 962: oils (rich in 18:3 �6,9,12), and
Page 963 and 964: eticulum subpopulations also finds
Page 965 and 966: CPT (DAG ↔ PC) Extensive involvem
Page 967 and 968: available (cf. Sec. V.C.4 and Ref.
Page 969 and 970: erol backbone of triacylglycerols c
Page 971 and 972: 14. E. Heinz. Biosynthesis of polyu
Page 973 and 974: 56. R. C. Clough, A. L. Matthis, S.
Page 975 and 976: 91. R. J. Heath and C. O. Rock. Eno
Page 977 and 978: 124. R. Schuch, F. M. Brück, M. Br
Page 979 and 980: Kader and P. Mazliak, eds.). Kluwer
Page 981 and 982: 197. Y. Cao, K. Oo, and A. H. C. Hu
Page 983 and 984:
241. M. C. Dobarganes, G. Márquez-
Page 985 and 986:
30 Genetic Engineering of Crops Tha
Page 987 and 988:
existing genes in the host plant ge
Page 989 and 990:
It becomes the plant breeder’s jo
Page 991 and 992:
previously mentioned low-linolenic
Page 993 and 994:
develop and apply methods, evaluate
Page 995 and 996:
enzyme with high activity for placi
Page 997 and 998:
activity in the oil palm mesocarp s
Page 999 and 1000:
Figure 4 Commercial applications of
Page 1001 and 1002:
and mildness. Because the perennial
Page 1003 and 1004:
In the context of developing increa
Page 1005 and 1006:
occurs esterified at the sn-2 posit
Page 1007 and 1008:
as high as coconut or palm kernel o
Page 1009 and 1010:
systems. Key to assessing the oppor
Page 1011 and 1012:
property encouraged us to look for
Page 1013 and 1014:
mercial lauric fats based on both P
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