Food lipids

That Is Describe and explain something about food lipids.

1. Holem Hashm Rasul
Collage Agriculture /
Department of Food Sciences
October /2014
Food Lipids

2. Lipids Lipids
Lipids are biological molecules that are insoluble in Lipids are biological molecules that are insoluble in
water but soluble in nonpolar solvents.water but soluble in nonpolar solvents.

3. Types of LipidsTypes of Lipids
1.Fats and oils (Triglycerides)1.Fats and oils (Triglycerides)
2.Phospholipids2.Phospholipids
3. Steroids as they do not contain fatty 3. Steroids as they do not contain fatty
acidsacids

4. Fats & Oils Triglycerides – Fats & Oils Triglycerides –
1. Predominate form of fat in foods1. Predominate form of fat in foods
and major storage form of fat in the bodyand major storage form of fat in the body, ,
also called triacylglycerols.also called triacylglycerols.
2. Esters of glycerol.2. Esters of glycerol.
3. Produced by esterification.3. Produced by esterification.
4. Formed when the hydroxyl groups of 4. Formed when the hydroxyl groups of
glycerol react with the carboxyl groups of glycerol react with the carboxyl groups of
fatty acids.fatty acids.

5. Triglycerides – Fats & OilsTriglycerides – Fats & Oils
HH
H C-OHH C-OH

H C-OHH C-OH
H C-OHH C-OH
H H

Fatty AcidFatty Acid
Fatty Acid Fatty Acid
Fatty Acid
Fatty Acid
Glycerol Monoglyceride Diglyceride TriglycerideGlycerol Monoglyceride Diglyceride Triglyceride

6. Structure of TriglycerideStructure of Triglyceride
OHCH
2
OH
OHCH
2
CH
O
(CH
2
)
14
CH
3
CHO
O
(CH
2
)
14
CH
3
CHO
O
(CH
2
)
14
CH
3
CHO
glycerol + 3 fatty acids ® triglyceride + H
2O
O
O
C(CH
2
)
14
CH
3
CHO
O
C(CH
2
)
14
CH
3
CH
2
O
O
C(CH
2
)
14
CH
3
CH
2

®
+ 3H
2
O

7. 1.1.HydrogenationHydrogenation
Unsaturated compounds rUnsaturated compounds react with Heact with H
22
CC=C bonds =C bonds C–CC–Cbondsbonds
2. 2. HydrolysisHydrolysis
Split by water and acid or enzyme catalystSplit by water and acid or enzyme catalyst
Produce glycerol and 3 fatty acidsProduce glycerol and 3 fatty acids
Properties of TriglyceridesProperties of Triglycerides

8. 1.1.Energy storageEnergy storage
2.2.Physical & thermal insulatorPhysical & thermal insulator
3.3.Carrier of fat soluble vitaminsCarrier of fat soluble vitamins
Functions of TriglyceridesFunctions of Triglycerides

9. Fatty AcidsFatty Acids
1.1.long-chain carboxylic acids.long-chain carboxylic acids.
2.2.Typically contain 12-18 carbon Typically contain 12-18 carbon
atoms.atoms.
3.3.insoluble in water.insoluble in water.
4.4.Can be saturated or unsaturated.Can be saturated or unsaturated.
5.5.Some contain double bondsSome contain double bonds
Copyright © 2007 by Pearson Education, Inc.
Publishing as Benjamin Cummings

10. Properties of SaturatedProperties of Saturated
Fatty AcidsFatty Acids
1.Saturated = C–C bonds
2.Closely packed
3.Strong attractions between chains
4.High melting points
5.Solids at room temperature
COOH
COOH
COOH

11. Properties of UnsaturatedProperties of Unsaturated
Fatty AcidsFatty Acids
1.1.Contain one or more double CContain one or more double C=C bonds=C bonds
2.2.Nonlinear chains do not allow molecules to pack Nonlinear chains do not allow molecules to pack
closelyclosely
3.3.Few interactions between chains.Few interactions between chains.
4.4.Low melting points.Low melting points.
5.5.Liquids at room temperature.Liquids at room temperature.
6.6.Cis double bonds.Cis double bonds.
CC
H
H
COOHcis double bond

12. © 2002 Wadsworth Publishing / Thomson Learning™

13. Peanuts

14. PhospholipidsPhospholipids
1.similar to triglycerides in structure except only 2
fatty acids + choline
2. Structure with two distinct parts
-Fat soluble part.
-Water soluble part (phosphate + N-compound)
3. Phospholipids in foods: Lecithin, egg yolks,
soybeans, wheat germ, peanuts

16. Functions of PhospholipidsFunctions of Phospholipids
1. Cell membrane structure1. Cell membrane structure
2. Emulsifier 2. Emulsifier
(helps keep fats in solution)(helps keep fats in solution)
- Fat digestion- Fat digestion
- Fat transport in blood- Fat transport in blood

17. SterolsSterols
Structure Consists
of Carbon Rings

18. Sterols (Sterols (Cholesterol)Cholesterol)
Cholesterol is a sterols – in foods andCholesterol is a sterols – in foods and
made by the liver; dietary sources made by the liver; dietary sources
include egg yolks, liver, meats, dairy include egg yolks, liver, meats, dairy
productsproducts

19. Functions of CholesterolFunctions of Cholesterol
1.1.Cell membrane structureCell membrane structure
2.2.Precurser for:Precurser for:
-Bile acids-Bile acids
-Steroid hormones-Steroid hormones
-Vitamin D-Vitamin D
3.3.Sources: Sources:
-Animal fats only-Animal fats only
-Made in liver (non-dietary essential)-Made in liver (non-dietary essential)

20. T
h
a
n
k
Y
o
u
T
h
a
n
k
Y
o
u