Upload
ricr2008
View
217
Download
0
Embed Size (px)
Citation preview
8/8/2019 1. Introduction- Chemistry of Fatty Acids and Triglyceride
1/30
Food Lipids
Professor David B. Min
Department of Food Science and Technology
The Ohio State University
Columbus, Ohio 43210
http://class.fst.ohio-state.edu/fst821
8/8/2019 1. Introduction- Chemistry of Fatty Acids and Triglyceride
2/30
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.
8/8/2019 1. Introduction- Chemistry of Fatty Acids and Triglyceride
3/30
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.
8/8/2019 1. Introduction- Chemistry of Fatty Acids and Triglyceride
4/30
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.
8/8/2019 1. Introduction- Chemistry of Fatty Acids and Triglyceride
5/30
GRADING
Exams (3) 60%
Final Exam 30%
Homework Assignments 10%
8/8/2019 1. Introduction- Chemistry of Fatty Acids and Triglyceride
6/30
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
8/8/2019 1. Introduction- Chemistry of Fatty Acids and Triglyceride
7/30
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
8/8/2019 1. Introduction- Chemistry of Fatty Acids and Triglyceride
8/30
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
8/8/2019 1. Introduction- Chemistry of Fatty Acids and Triglyceride
9/30
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
8/8/2019 1. Introduction- Chemistry of Fatty Acids and Triglyceride
10/30
CLASSIFICATION OF LIPIDS
8/8/2019 1. Introduction- Chemistry of Fatty Acids and Triglyceride
11/30
Triacylglycerol
8/8/2019 1. Introduction- Chemistry of Fatty Acids and Triglyceride
12/30
Simple Lipids
A. Neutral fats - Triglycerides
2
2
2
2
++ 3 2
8/8/2019 1. Introduction- Chemistry of Fatty Acids and Triglyceride
13/30
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
8/8/2019 1. Introduction- Chemistry of Fatty Acids and Triglyceride
14/30
Simple Lipids
Cholesterol and Esters
17CH CH2
CH3
CH2 CH2 CH
CH3
CH3
53 6
HOFatty acids
8/8/2019 1. Introduction- Chemistry of Fatty Acids and Triglyceride
15/30
Simple Lipids
Retinol (Vitamin A1) and Esters
3 3
3
3 3
2+ fatty acids
8/8/2019 1. Introduction- Chemistry of Fatty Acids and Triglyceride
16/30
Simple Lipids
Vitamin D and Esters
R = C8H17 in Vitamin D3
R = C9H17 in Vitamin D2
65 7
R
HO
H2C8
fatty acids
8/8/2019 1. Introduction- Chemistry of Fatty Acids and Triglyceride
17/30
CHEMISTRY OF FATTY ACIDS
8/8/2019 1. Introduction- Chemistry of Fatty Acids and Triglyceride
18/30
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
8/8/2019 1. Introduction- Chemistry of Fatty Acids and Triglyceride
19/30
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
8/8/2019 1. Introduction- Chemistry of Fatty Acids and Triglyceride
20/30
Monoethenoic Acid - Cis
[1 9
C2
H
10 9 8 7 6 5 4 3 2 1
9, 10- Octadecenoicacid
9 - Octadecenoic acid
8/8/2019 1. Introduction- Chemistry of Fatty Acids and Triglyceride
21/30
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
8/8/2019 1. Introduction- Chemistry of Fatty Acids and Triglyceride
22/30
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
8/8/2019 1. Introduction- Chemistry of Fatty Acids and Triglyceride
23/30
Ethynoic Acids
Common Name Systematic Name
Tariric acid 6-octadecylinic acid
8/8/2019 1. Introduction- Chemistry of Fatty Acids and Triglyceride
24/30
Hydroxy and Keto Acids
Common Name Systematic Name
Dihydroxystrearic 9,10-dihydroxyoctadecanoic
Lactarinic 6-keto-octadecanoic
8/8/2019 1. Introduction- Chemistry of Fatty Acids and Triglyceride
25/30
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
8/8/2019 1. Introduction- Chemistry of Fatty Acids and Triglyceride
26/30
Triacylglycerol
8/8/2019 1. Introduction- Chemistry of Fatty Acids and Triglyceride
27/30
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
8/8/2019 1. Introduction- Chemistry of Fatty Acids and Triglyceride
28/30
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
8/8/2019 1. Introduction- Chemistry of Fatty Acids and Triglyceride
29/30
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
+ +
8/8/2019 1. Introduction- Chemistry of Fatty Acids and Triglyceride
30/30
Chromatogram of Fatty Acid Methyl Ester