Lipids in Foods

1. The Structure of Fatty Acids and Lipids

A. Fatty Acids


1. Fatty Acid Nomenclature


2. General Comments on Structure and Occurrence


3. Saturated (Alkanoic) Acids


4. Monoenoic (Alkenoic) Acids


5. Methylene-Interrupted Polyenoic Acids


6. Other Acids

B. Lipids


1. General Comments on Lipid Structure


2. Acylglycerols (Glycerides)


3. Acyl Derivatives of Alcohols Other than Glycerol


4. Glycosyldiacylglycerols


5. Phosphoglycerides (Phosphatidic Acids, Phosphatidylglycerols, Phosphatidylcholine, Phosphatidylethanolamine, Phosphatidylserine, Phosphatidylinositide)


6. Ether Lipids


7. Sphingolipids (Ceramides, Cerebrosides, Gangliosides, Phosphosphingolipids, Glycosphingolipids)


2. The Separation and Isolation of Fatty Acids and Lipids

A. Introduction

B. Distillation

C. Crystallization

D. Urea Fractionation

E. Adsorption Chromatography on Silica

F. Adsorption Chromatography on Silica Impregnated with Silver Nitrate

G. High-Performance Liquid Chromatography

H. Gas-Liquid Chromatography

I. Isolation of Some of the More Common Unsaturated Acids


3. The Analysis of Fatty Acids and Lipids

A. The Nature of the Problem

B. Component Acids, Alcohols, and Aldehydes

C. Component Lipids

D. Enzymatic Deacylation of Lipids


1. Hydrolysis with Pancreatic Lipase


2. Regio- and Stereospecific Analysis of Triacylglycerols


3. Stereospecific Analysis of Phosphoglycerides

E. Attempts to Separate Individual Lipid Species


4. The Biosynthesis and Metabolism of Fatty Acids and Lipids

A. Fatty Acid Biosynthesis


1. De Novo Synthesis of Palmitic and Other Saturated Acids


2. Chain Elongation


3. Monoene Biosynthesis


4. Polyene Biosynthesis


5. Essential Fatty Acids and Prostaglandins

B. Lipid Biosynthesis


1. General Comments


2. Triacylglycerols


3. Phosphoglycerides

C. Fatty Acid and Lipid Metabolism


1. The Digestion and Absorption of Fats


2. Bio-Oxidation of Fatty Acids

D. Possible Harmful Effects of Some Dietary Lipids


1. Heart Disease


2. Long-Chain Monoene Acids

E. Membranes


5. Physical Properties

A. Polymorphism and Crystal Structure


1. Introduction


2. Acids


3. Glycerides

B. Spectroscopic Properties


1. Ultraviolet Spectroscopy


2. Infrared Spectroscopy


3. Nuclear Magnetic Resonance Spectroscopy


4. Mass Spectrometry


6. Catalytic Hydrogenation, Chemical Reduction, and Biohydrogenation

A. Catalytic Hydrogenation


1. Introduction


2. Methyl Oleate


3. Methyl Linoleate


4. Methyl Linolenate


5. Reaction Conditions

B. Chemical Reduction

C. Biohydrogenation


7. Oxidation

A. Oxidation by Oxygen


1. Introduction


2. Autoxidation


3. Reaction with Singlet Oxygen


4. Enzymic Oxidation


5. Reactions of Hydroperoxides

B. Epoxidation

C. Hydroxylation

D. Oxidative Fission


8. Other Reactions of Double Bonds

A. Halogenation

B. Metathesis

C. Stereomutation, Double Bond Migration, Cyclization

D. Dimerization

E. Other Double Bond Reactions


9. Reactions of the Carboxyl Group

A. Hydrolysis

B. Esterification, Alcoholysis, Acidolysis, Interesterification


1. Esterification


2. Alcoholysis


3. Acidolysis


4. Interesterification

C. Acid Chlorides and Anhydrides

D. Nitrogen- and Sulfur-Containing Derivatives

E. α-Anions of Carboxylic Acids

F. Peroxy Acids


10. Synthesis

A. Why Synthesis?

B. Synthesis of Acids


1. The Acetylenic Route to Cis-Mono- and Poly-Enoic Acids


2. The Wittig Reaction


3. Isotopically Labeled Acids

C. Synthesis of Acylglycerols


1. Introduction


2. Acylation Procedures


3. Protecting Groups


4. Monoacylglycerols


5. 1,3-Diacylglycerols


6. 1,2-Diacylglycerols


7. Triacylglycerols


8. Optically Active Acylglycerols

D. Synthesis of Phosphoglycerides


1. Introduction


2. Preparation from 1,2-Diacylglycerols


3. Acylation of Glycerophosphocholine or Glycerophosphoethanolamine


4. Preparation of Phosphatidic Acids and of Phosphatidyl Esters Therefrom


11. Recovery of Fats and Oils from Their Sources

A. Introduction

B. Methods of Obtaining Crude Fats and Oils


1. General


2. Soybean and Cottonseed Preparation


3. Recovery of Oil from Oilseeds


4. Recovery of Oil from Fruit Pulps


5. Rendering of Animal Fats


12. Refining

A. Introduction

B. Alkali Refining Method


1. Batch Refining


2. Conventional Continuous Alkali Refining


3. Zenith Process


4. Miscella Refining


5. Soapstock Handling

C. Other Refining Methods


1. Physical Refining


2. Degumming


3. Miscellaneous Refining Methods

D. Measuring Refining Loss


13. Bleaching

A. Color Standards

B. Methods of Bleaching


1. Heat


2. Chemical Oxidation


3. Adsorption

C. Bleaching by Adsorption


1. Theory


2. Bleaching Earths


3. Bleaching Conditions

D. Batch Bleaching

E. Continuous Bleaching

F. Bleaching in Solvent


14. Hydrogenation

A. The Reaction

B. Selectivity

C. Hydrogenation Requirements


1. Hydrogen Gas


2. Oil


3. Catalyst

D. Procedure

E. Effect of Process Conditions

F. Continuous Hydrogenation


15. Deodorization

A. Introduction

B. Deodorization Theory

C. Variables in Deodorizer Operations


1. Vacuum


2. Temperature


3. Stripping Steam

D. General Deodorizing Equipment


1. Batch Deodorizers


2. Continuous Deodorizers


3. Semi-Continuous Deodorizers

E. Important Factors in Deodorization


1. Air Contact


2. Stripping Steam


3. Additives


4. Temperature


5. Vacuum


6. Shut-Downs


7. Nitrogen Blanketing


16. Fractionation and Winterization of Edible Fats and Oils

A. Principles of Fractionation

B. Fractionation Processes


1. Dry Fractionation


2. Lanza Fractionation


3. Solvent Fractionation

C. Examples of Fractionation


1. PHL Oil


2. Fractionated Palm Oil


3. Liquid Shortening


4. Winterization of Cottonseed Oil and of Blends with Soybean

D. Crystal Inhibitors

E. Stabilizers


17. Interesterification

A. Introduction

B. Types of Interesterification


1. Random


2. Directed

C. Catalysts

D. Procedure

E. Examples


18. Margarines and Shortenings

A. Definitions

B. History

C. Structure of a Plastic Fat

D. Production of Shortening

E. Types of Shortening


1. Plastic Shortenings


2. Pourable Shortenings


3. Solid (Dry) Shortenings

F. Shortening Uses


1. Baked Goods


2. Fried Foods


3. Icings and Cream Fillers


4. Frozen Foods

G. Production of Margarine


1. Fat Phase


2. Aqueous Phase


3. Blending and Chilling


4. Tempering

H. Margarine Uses


1. Table


2. Bakery


19. Flavor Stability and Antioxidants

A. Introduction

B. Analytical Methods of Studying Flavor Stability


1. Peroxide Value


2. Schaal Test


3. Active Oxygen Method (A.O.M.) (Swift Stability Test)


4. Anisidine Value


5. TOTOX Value


6. Volatiles

C. Evaluation of Shelf Life


1. Storage


2. Accelerated Storage


3. Room odor

D. Flavor Evaluation


1. Panel Training


2. Uniform Presentation


3. Scoring Scale


4. Statistical Evaluation of Data

E. Antioxidants


1. Primary Antioxidants


2. Synergistic Antioxidants