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Food Lipids

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Title: Food Lipids


1
Food Lipids
  • Professor David B. Min
  • Department of Food Science and Technology
  • The Ohio State University
  • Columbus, Ohio 43210
  • Min.2_at_osu.edu
  • http//class.fst.ohio-state.edu/fst821

2
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
and hydrogenation, fractionation of fats and
oils, current instrumental analyses of lipids and
biotechnology of fats and oils.
3
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.

4
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.

5
GRADING
Exams (3) 60 Final Exam 30 Homework
Assignments 10
6
Course Schedule
Class Topics 1. Introduction and
Classification of Lipid 2. Chemistry of Fatty
Acids 3. Chemistry of Triglycerides 4. Chromatog
raphic Analyses of Lipids 5. UV IR
Spectrometric Analyses 6. NMR Spectrometric
Analyses 7. NMR Spectrometric Analyses 8. NMR
and Mass Spectrometric Analyses 9. Mass
Spectrometry 10. Mass Spectrometry
7
Course Schedule
Class Topics 11. Identification of Lipid
Compounds by IR, NMR, MS 12. Examination 13. Lipi
d Oxidation - Chemistry of Oxygen 14. Free
Radical Lipid Oxidation 15. Free Radical Lipid
Oxidation 16. Singlet Oxygen Lipid
Oxidation 17. Singlet Oxygen Lipid
Oxidation 18. Singlet Oxygen Oxidation in Milk
Products 19. Enzymatic Lipid Oxidation 20. Evalu
ation of Flavor Quality and Stability
8
Course Schedule
Class Topics 21. Chemical Reactions in
Deep-Fat Frying Oils 22. Examination 23. Polymor
phism 24. Application of Polymorphism in
Foods 25. Interesterification 26. Interesterifi
cation 27. Hydrogenation 28. Hydrogenation 29.
Examination
9
Reference Books
1. Flavor Chemistry of Fats and Oils by David B.
Min and Thomas H. Smouse. American Oil
Chemists' Society, Champaign, IL. 1985 2. Flavor
Chemistry of Lipid Foods by David B. Min and
Thomas H. Smouse. American Oil Chemists'
Society, Champaign, IL. 1989 3. Food Lipids and
Health by Richard E. McDonald and David B. Min.
Marcel Dekker, Inc. New York, NY. 1996 4. Food
Lipids by Casimir C. Akoh and David B. Min,
Marcel Dekker, Inc. New York,
NY.1998 5. Bailey's Industrial Oils and Fat
Products by Y.H. Hui Wiley Interscience. New
York, NY. 1996 6. Food Chemistry, 3rd Edition by
O. Fennema, Marcel Dekker, Inc. New York,
NY.1998
10
CLASSIFICATION OF LIPIDS
11
Triacylglycerol
12
Simple Lipids
A. Neutral fats - Triglycerides
13
Simple Lipids
  • Waxes
  • Fatty acids Long chain alcohol
  •  
  •  Beeswax (myricyl palmitate)
  •  
  •  
  • Spermaceti (cetyl palmitate)
  •  


O
C
H
O C C
H
30
61
15
31
O
C
H
O C C
H
16
33
15
31
14
Simple Lipids
Cholesterol and Esters


C

H

C

H



3
3
C

H
C

H

C

H

C

H

C

H




2
2
2
17

C

H


3


5
3
6

Fatty acids

HO

15
Simple Lipids
Retinol (Vitamin A1) and Esters
16
Simple Lipids
Vitamin D and Esters    R C8H17 in Vitamin D3 R
C9H17 in Vitamin D2
R


H

C


2
8

5

7
6


H

O

fatty acids

17
CHEMISTRY OF FATTY ACIDS
18
Classification and Structure-Saturated Fatty
Acids
Common Name Systematic Name
Formula Butyric acid n-butanoic Caproi
c acid n-hexanoic Caprylic
acid n-octanoic Capric acid n-decanoic
Lauric acid n-dodecanoic
19
Common Name Systematic Name
Formula Myristic acid n-tetradecanoic Palm
itic acid n-hexadecanoic Stearic
acid n-octadecanoic Arachidic
acid n-eicosanoic Behenic acid n-docosanoic
Lignoceric acid n-tetracosanoic
20
Monoethenoic Acid - Cis
10 9 8 7 6
5 4 3 2 1
? 9, 10 - Octadecenoic acid 9 - Octadecenoic
acid
21
Common Name of Fatty Acids
Common Name Systematic Name cis Myristoleic 9-te
tradecenoic acid Palmitoleic 9-hexadecenoic
acid Oleic 9-octadecenoic acid Vaccenic 11-
octadecenoic acid Erucic 13-docosenoic acid
22
Polyethenoic Acids
Common Name Systematic Name Linoleic 9,12-octa
decadienoic acid(cis,cis) or Octadeca-9,12-dien
oic acid Linolenic 9,12,15-octadecatrienoic
acid Arachidonic 5,8,11,14-eicosatetraenoic
acid 4,8,12,16-eicosatetraenoic acid
23
Ethynoic Acids
Common Name Systematic Name Tariric
acid 6-octadecylinic acid
24
Hydroxy and Keto Acids
Common Name Systematic Name Dihydroxystrearic
9,10-dihydroxyoctadecanoic Lactarinic
6-keto-octadecanoic
25
Cyclic Acids
Chaulmoogric acid
13-(2-cyclopentenyl) tridecanoic acid
O
4 5 1
C
H
C
H
C
H
(
C
H
)
C
O
H
12
2
2
2
C
H
C
H
3 2
26
Triacylglycerol
27
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 60?C 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
28
Fatty Acid Analysis
2. For quantification the same as above
except a. add internal standard free fatty acid
to oil. b. add equal volumes of sodium methoxide
and BF3-methanol, 0.5 - 1.0 ml of each. c.
heat 70 - 80?C for 50 - 60 min. (if, after 20
min. of heating the sample is not dissolved,
add more sodium methoxide and BF3-methanol).
29
Disadvantages of Gas Chromatography
Material has to be volatilized at 250C without
decomposition.
Methylester
Fatty Acids

O
O
Reflux


R C OH CH
OH H
SO
R C O CH
3
2
4
3
Volatile in Gas Chromatography
O
CH
O C R
2
O
O
CH
ONa
3
R C O CH
3
CH O C R
CH
OH
3

3
Volatile in Gas Chromatography
O
CH
O C R
2
30
Chromatogram of Fatty Acid Methyl Ester
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