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Food Lipids
Professor David B. Min
Department of Food Science and Technology
The Ohio State University
Columbus, Ohio 43210
[email protected]
http://class.fst.ohio-state.edu/fst821
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DESCRIPTION
This course will cover an in-depth study of chemical and
physical properties of edible fats and oils and the roles of
their
functional properties in food systems. Major topics covered
will
be chemistry of triglycerides, auto and thermal oxidation,
antioxidants, chemical reactions in deep-fat frying,
principles
and application of polymorphism, interesterification
andhydrogenation, fractionation of fats and oils, current
instrumental analyses of lipids and biotechnology of fats
and
oils.
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OBJECTIVES
To describe the relationship between the composition of
tryglycerides and their chemical and physical properties.
To describe the chemical reactions of auto and thermal
oxidation of oil and the mechanisms of antioxidants.
To describe the chemical mechanisms of hydrogenation and
interesterification and their applications in fats and oils.
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OBJECTIVES
To apply the physical and chemical methods to convert
readily-
available fats into tailor-made fats, that may be in greater
demand or
more desirable economically or nutritionally than the original
fats.
To describe the current instrumental and analytical methods
as
research tools in the fats and oils area.
To describe the application of biotechnology to the
modification
and production of fats and oils.
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GRADING
Exams (3) 60%
Final Exam 30%
Homework Assignments 10%
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Course Schedule
Class Topics
1. Introduction and Classification of Lipid
2. Chemistry of Fatty Acids3. Chemistry of Triglycerides
4. Chromatographic Analyses of Lipids
5. UV & IR Spectrometric Analyses
6. NMR Spectrometric Analyses
7. NMR Spectrometric Analyses8. NMR and Mass Spectrometric
Analyses
9. Mass Spectrometry
10. Mass Spectrometry
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Course Schedule
Class Topics
11. Identification of Lipid Compounds by IR, NMR, MS
12. Examination
13. Lipid Oxidation - Chemistry of Oxygen
14. Free Radical Lipid Oxidation
15. Free Radical Lipid Oxidation
16. Singlet Oxygen Lipid Oxidation17. Singlet Oxygen Lipid
Oxidation
18. Singlet Oxygen Oxidation in Milk Products
19. Enzymatic Lipid Oxidation
20. Evaluation of Flavor Quality and Stability
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Course Schedule
Class Topics
21. Chemical Reactions in Deep-Fat Frying Oils
22. Examination
23. Polymorphism
24. Application of Polymorphism in Foods
25. Interesterification
26. Interesterification27. Hydrogenation
28. Hydrogenation
29. Examination
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Reference Books
1. Flavor Chemistry of Fats and Oilsby David B. Min and
Thomas
H. Smouse. American Oil Chemists' Society, Champaign, IL.
1985
2. Flavor Chemistry of Lipid Foodsby David B. Min and Thomas
H.
Smouse. American Oil Chemists' Society, Champaign, IL. 1989
3. Food Lipids and Healthby Richard E. McDonald and David B.
Min.
Marcel Dekker, Inc. New York, NY. 1996
4. Food Lipidsby Casimir C. Akoh and David B. Min, Marcel
Dekker, Inc. New York, NY.1998
5. Bailey's Industrial Oils and Fat Productsby Y.H. Hui
Wiley
Interscience. New York, NY. 1996
6. Food Chemistry, 3rd Edition by O. Fennema, Marcel Dekker,
Inc.
New York, NY.1998
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CLASSIFICATION OF LIPIDS
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Triacylglycerol
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Simple Lipids
A. Neutral fats - Triglycerides
2
2
2
2
++ 3 2
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Simple Lipids
B. Waxes
Fatty acids Long chain alcohol
Beeswax (myricyl palmitate)
Spermaceti (cetyl palmitate)
O
C30H61 O C C15H31
O
C16H33 O C C15H31
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Simple Lipids
Cholesterol and Esters
17CH CH2
CH3
CH2 CH2 CH
CH3
CH3
53 6
HOFatty acids
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Simple Lipids
Retinol (Vitamin A1) and Esters
3 3
3
3 3
2+ fatty acids
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Simple Lipids
Vitamin D and Esters
R = C8H17 in Vitamin D3
R = C9H17 in Vitamin D2
65 7
R
HO
H2C8
fatty acids
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CHEMISTRY OF FATTY ACIDS
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Classification and Structure-Saturated Fatty Acids
Common Name Systematic Name Formula
Butyric acid n-butanoic
Caproic acid n-hexanoic
Caprylic acid n-octanoic
Capric acid n-decanoic
Lauric acid n-dodecanoic
C C C
C C C
C C C
C C C
C C C
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Common Name Systematic Name Formula
Myristic acid n-tetradecanoic
Palmitic acid n-hexadecanoic
Stearic acid n-octadecanoic
Arachidic acid n-eicosanoic
Behenic acid n-docosanoic
Lignoceric acid n-tetracosanoic
C C C
C C C
C C C
C C C
C C C
C C C
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Monoethenoic Acid - Cis
[1 9
C2
H
10 9 8 7 6 5 4 3 2 1
9, 10- Octadecenoicacid
9 - Octadecenoic acid
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Common Name of Fatty Acids
Common Name Systematic Name cis
Myristoleic 9-tetradecenoic acid
Palmitoleic 9-hexadecenoic acid
Oleic 9-octadecenoic acid
Vaccenic 11-octadecenoic acid
Erucic 13-docosenoic acid
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Polyethenoic Acids
Common Name Systematic Name
Linoleic 9,12-octadecadienoic acid(cis,cis)
orOctadeca-9,12-dienoic acid
Linolenic 9,12,15-octadecatrienoic acid
Arachidonic 5,8,11,14-eicosatetraenoic acid
4,8,12,16-eicosatetraenoic acid
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Ethynoic Acids
Common Name Systematic Name
Tariric acid 6-octadecylinic acid
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Hydroxy and Keto Acids
Common Name Systematic Name
Dihydroxystrearic 9,10-dihydroxyoctadecanoic
Lactarinic 6-keto-octadecanoic
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Cyclic Acids
Chaulmoogric acid
13-(2-cyclopentenyl) tridecanoic acid
4 5 1
3 2
C H2
C H2
C H (C H2
)12 C O H
O
C H C H
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Triacylglycerol
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Fatty Acid Analysis
1. Method for oils :
a. measure 5 - 15 mg oil into small vial.b. add 0.4 - 0.8 ml
sodium methoxide.
c. heat 60rC for 50 - 60 min.
d. add 0.4 - 0.8 ml saturated NaCl solution.
e. extract with 0.4 ml petroleum ether.
f. check derivertization (TLC-chloroform solvent).
g. Gas Chromatography analysis
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2. For quantification : the same as above except
a. add internal standard free fatty acid to oil.
b. add equal volumes of sodium methoxide andBF3-methanol, 0.5 -
1.0 ml of each.
c. heat 70 - 80rC for 50 - 60 min. (if, after 20 min.
of heating the sample is not dissolved, add more
sodium methoxide and BF3-methanol).
Fatty Acid Analysis
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Disadvantages ofGas Chromatography
Material has to be volatilized at 250C without
decomposition.
R C OH CH3OH H2SO4
O
R C O CH3
O
CH2 O C R
CH O C R
CH2 O C R
O
O
O
CH3OH
O
R C O CH3CH3ONa
Fatty Acids Methylester
Reflux
+3
Volatile in Gas Chromatography
Volatile in Gas Chromatography
+ +
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Chromatogram of Fatty Acid Methyl Ester
