View
223
Download
0
Category
Preview:
Citation preview
8/10/2019 EEB304 LECT16 Oils Spring11
1/52
Thursday LectureVegetable
Oils and Waxes
Reading: Textbook, Chapter 9
8/10/2019 EEB304 LECT16 Oils Spring11
2/52
A Plethora of Peppers
Black Pepper Piper nigrum (Asia)
Red Pepper Capsicum spp. (Mexico/South America)
Melegueta Pepper Aframomum (Africa)
Brazilian (or Pink) Pepper Schinus
Drupe of member of Anacardiaceaesome people exhibit
allergic reaction
8/10/2019 EEB304 LECT16 Oils Spring11
3/52
Quiz
1. Two different plants both give us a spice called pepper
Chili pepper (Capsicum) and Black pepper (Piper)which
is native to the Old World and which to the New World?
2. Name a major vegetable oil crop. Where is it originallynative?
8/10/2019 EEB304 LECT16 Oils Spring11
4/52
Vegetable Oils
Plant oilsmostly acylglycerides
Glycerol3-carbon backbone
Figure 9.3, p. 221
8/10/2019 EEB304 LECT16 Oils Spring11
5/52
Vegetable Oils
Plant oilsmostly acylglycerides
Glycerol3-carbon backbone
Acyl groupsmostly fatty acids = chain of carbon atoms
Figure 9.3, p. 221
8/10/2019 EEB304 LECT16 Oils Spring11
6/52
Triacylglyceride structureFigure 9.3, p. 221
8/10/2019 EEB304 LECT16 Oils Spring11
7/52
Vegetable Oils
Plant oilsmostly acylglycerides
Glycerol3-carbon backbone
Acyl groupsmostly fatty acids = chain of carbon atoms
Properties of acyl groups:
1. Lengthlonger = higher melting point
Figure 9.3, p. 221
8/10/2019 EEB304 LECT16 Oils Spring11
8/52
Vegetable Oils
Plant oilsmostly acylglycerides
Glycerol3-carbon backbone
Acyl groupsmostly fatty acids = chain of carbon atoms
Properties of acyl groups:
1. Lengthlonger = higher melting point
2. Unsaturationthe presence of double-bonds between carbons
Figure 9.3, p. 221
8/10/2019 EEB304 LECT16 Oils Spring11
9/52
Vegetable Oils
Plant oilsmostly acylglycerides
Glycerol3-carbon backbone
Acyl groupsmostly fatty acids = chain of carbon atoms
Properties of acyl groups:
1. Lengthlonger = higher melting point
2. Unsaturationthe presence of double-bonds between carbons
- monounsaturated = has 1 double bond
Figure 9.3, p. 221
8/10/2019 EEB304 LECT16 Oils Spring11
10/52
Vegetable Oils
Plant oilsmostly acylglycerides
Glycerol3-carbon backbone
Acyl groupsmostly fatty acids = chain of carbon atoms
Properties of acyl groups:
1. Lengthlonger = higher melting point
2. Unsaturationthe presence of double-bonds between carbons
- monounsaturated = has 1 double bond
- polyunsaturated = has 2 or more double bonds
Figure 9.3, p. 221
8/10/2019 EEB304 LECT16 Oils Spring11
11/52
Vegetable Oils
Plant oilsmostly acylglycerides
Glycerol3-carbon backbone
Acyl groupsmostly fatty acids = chain of carbon atoms
Properties of acyl groups:
1. Lengthlonger = higher melting point
2. Unsaturationthe presence of double-bonds between carbons
- monounsaturated = has 1 double bond
- polyunsaturated = has 2 or more double bonds
Double bondsgenerally lower melting point of compound
Figure 9.3, p. 221
8/10/2019 EEB304 LECT16 Oils Spring11
12/52
Triacylglyceride structureFigure 9.3, p. 221
8/10/2019 EEB304 LECT16 Oils Spring11
13/52
Vegetable OilsThe Plant View
Why do plants produce oils?
8/10/2019 EEB304 LECT16 Oils Spring11
14/52
Vegetable OilsThe Plant View
Why do plants produce oils?
Answer: high energy content (caloric value)compact way to
store energy
8/10/2019 EEB304 LECT16 Oils Spring11
15/52
Vegetable OilsThe Plant View
Why do plants produce oils?
Answer: high energy content (caloric value)compact way to
store energy
Where do plants produce and store oils?
8/10/2019 EEB304 LECT16 Oils Spring11
16/52
Vegetable OilsThe Plant View
Why do plants produce oils?
Answer: high energy content (caloric value)compact way to
store energy
Where do plants produce and store oils?Answer: seeds, particularly endosperm or cotyledon(s)
8/10/2019 EEB304 LECT16 Oils Spring11
17/52
Vegetable OilsThe Human
View
Why do people consume vegetable oils (and other fats)?
Box 9.1, p. 222
bl il h
8/10/2019 EEB304 LECT16 Oils Spring11
18/52
Vegetable OilsThe Human
View
Why do people consume vegetable oils (and other fats)?
Answer: high energy contentwe retain a craving for fats that was
an advantage for our ancestors at a time when it was difficult to
obtain fats
Box 9.1, p. 222
bl Oil h
8/10/2019 EEB304 LECT16 Oils Spring11
19/52
Vegetable OilsThe Human
View
Why do people consume vegetable oils (and other fats)?
Answer: high energy contentwe retain a craving for fats that was
an advantage for our ancestors at a time when it was difficult to
obtain fats
What has changed?
- widespread availability of fats/oils
Box 9.1, p. 222
V bl Oil Th H
8/10/2019 EEB304 LECT16 Oils Spring11
20/52
Vegetable OilsThe Human
View
Why do people consume vegetable oils (and other fats)?
Answer: high energy contentwe retain a craving for fats that was
an advantage for our ancestors at a time when it was difficult to
obtain fats
What has changed?
- widespread availability of fats/oils
- increase in human lifespan
Revealing health issues in high consumption of fats
Box 9.1, p. 222
A l l id H l h I
8/10/2019 EEB304 LECT16 Oils Spring11
21/52
AcylglyceridesHealth Issues
Consumption Increasing
World Consumption Projected to be up16% - 1998-2001 Figure 9.2, p. 220
A l l id H l h I
8/10/2019 EEB304 LECT16 Oils Spring11
22/52
AcylglyceridesHealth Issues
Consumption Increasing
World Consumption Projected to be up12% - 2006-2011 Figure 9.2, p. 220
A l l id H lth I
8/10/2019 EEB304 LECT16 Oils Spring11
23/52
AcylglyceridesHealth Issues
25% of deaths in U.S. due to heart disease (2007) - #1 cause
Box 9.1, p. 222
A l l id H lth I
8/10/2019 EEB304 LECT16 Oils Spring11
24/52
AcylglyceridesHealth Issues
25% of deaths in U.S. due to heart disease (2007) - #1 cause
Correlation between blood cholesterol & heart disease
Box 9.1, p. 222
A l l id H lth I
8/10/2019 EEB304 LECT16 Oils Spring11
25/52
AcylglyceridesHealth Issues
25% of deaths in U.S. due to heart disease (2007) - #1 cause
Correlation between blood cholesterol & heart disease
Plants do not produce cholesterol
Box 9.1, p. 222
A l l id H lth I
8/10/2019 EEB304 LECT16 Oils Spring11
26/52
AcylglyceridesHealth Issues
25% of deaths in U.S. due to heart disease (2007) - #1 cause
Correlation between blood cholesterol & heart disease
Plants do not produce cholesterol
Correlationsaturated dietary fatsarterial plaque formation
Box 9.1, p. 222
A l l id H lth I
8/10/2019 EEB304 LECT16 Oils Spring11
27/52
AcylglyceridesHealth Issues
25% of deaths in U.S. due to heart disease (2007) - #1 cause
Correlation between blood cholesterol & heart disease
Plants do not produce cholesterol
Correlationsaturated dietary fatsarterial plaque formation
Conclusion: exchange saturated for unsaturated fats in foods
Box 9.1, p. 222
8/10/2019 EEB304 LECT16 Oils Spring11
28/52
Acylglycerides Health Issues
8/10/2019 EEB304 LECT16 Oils Spring11
29/52
AcylglyceridesHealth Issues
25% of deaths in U.S. due to heart disease (2007) - #1 cause
Correlation between blood cholesterol & heart disease
Plants do not produce cholesterol
Correlationsaturated dietary fatsarterial plaque formation
Conclusion: exchange saturated for unsaturated fats in foods
Problem: polyunsaturated fatslinked to production of free
radicals, which are carcinogenic
Recommendation: mono-unsaturated fats appear best for health,based on currently available information
Problem: saturated fats taste better
Box 9.1, p. 222
8/10/2019 EEB304 LECT16 Oils Spring11
30/52
Trans Fats
Saturated fats (animal fats, tropical vegetable fats)link to
heart disease
8/10/2019 EEB304 LECT16 Oils Spring11
31/52
Trans Fats
Saturated fats (animal fats, tropical vegetable fats)link to
heart disease
Polyunsaturated fatsvegetable oils, liquid at room temp.
8/10/2019 EEB304 LECT16 Oils Spring11
32/52
Trans Fats
Saturated fats (animal fats, tropical vegetable fats)link to
heart disease
Polyunsaturated fatsvegetable oils, liquid at room temp.
Hydrogenationbubble hydrogen gas through vegetable oil,
increases the saturation
8/10/2019 EEB304 LECT16 Oils Spring11
33/52
Trans Fats
Saturated fats (animal fats, tropical vegetable fats)link to
heart disease
Polyunsaturated fatsvegetable oils, liquid at room temp.
Hydrogenationbubble hydrogen gas through vegetable oil,
increases the saturation
Completely saturatedhard, like waxnot useful
8/10/2019 EEB304 LECT16 Oils Spring11
34/52
Trans Fats
Saturated fats (animal fats, tropical vegetable fats)link to
heart disease
Polyunsaturated fatsvegetable oils, liquid at room temp.
Hydrogenationbubble hydrogen gas through vegetable oil,
increases the saturation
Completely saturatedhard, like waxnot useful
Partial saturationcreamy consistency, useful for spreads
also more chemically stable, longer shelf life
8/10/2019 EEB304 LECT16 Oils Spring11
35/52
Trans Fats
Saturated fats (animal fats, tropical vegetable fats)link to
heart disease
Polyunsaturated fatsvegetable oils, liquid at room temp.
Hydrogenationbubble hydrogen gas through vegetable oil,
increases the saturation
Completely saturatedhard, like waxnot useful
Partial saturationcreamy consistency, useful for spreads
also more chemically stable, longer shelf life
Problemcreates trans type of bondshealth problems
8/10/2019 EEB304 LECT16 Oils Spring11
36/52
Omega 3, Omega 6 fats
Omega n refers to position of double bond relative to
methyl end of fatty acid
Required in human dietomega 3, omega 6 types
Associated with health benefits
8/10/2019 EEB304 LECT16 Oils Spring11
37/52
Extraction of Vegetable Oils
Basic Approaches
I. Mechanical Extraction
- cold pressing means no heat applied
- hot pressing means external heart is applied
Note: screw press now widely usedallows
continuous processing and separation of
residual cake
Figure 9.6, 9.7, p. 227
8/10/2019 EEB304 LECT16 Oils Spring11
38/52
Extraction of Vegetable Oils
Basic Approaches
I. Mechanical Extraction
- cold pressing means no heat applied
- hot pressing means external heart is applied
Note: screw press now widely usedallows
continuous processing and separation of
residual cake
II. Solvent Extraction- organic solvent (e.g. hexane)
Notes: more efficient (less oil left behind) but
requires processing because solvent must be
removed
Figure 9.6, 9.7, p. 227
i f bl il
8/10/2019 EEB304 LECT16 Oils Spring11
39/52
Processing of Vegetable Oils
Refining: use alkali to remove free fatty acids
Degumming: extraction with water to remove mucilaginous material
Bleaching: removal of pigments that produce color
Deodorizing: removal of aromatic compounds through steam heating
Winterizing: removal of particles by precipation at low temperature +
filtering
Hydrogenation: increasing the saturation of fatty acids (use hydrogen
gas + catalyst) raise melting point
Figure 9.8, p. 229
C S f V t bl Oil
8/10/2019 EEB304 LECT16 Oils Spring11
40/52
Common Sources of Vegetable OilsPolyunsaturated
- linseed oil (Linum usitatissimum- seeds)- tung oil (Aleurites fordiiseeds)
Unsaturated
- Safflower (Carthamus1-seeded fruits)
- soybean (Glycine maxseeds)
- sunflower (Helianthus annuus1-seeded fruits)
- corn oil (Zea maysgerm)
- sesame oil (Sesamum indicumseeds)
- cottonseed oil (Gossypiumseeds)
- canola oil (Brassicaseeds)
Moderately saturated
- peanut oil (Arachis hypogaeaseeds)
- olive oil (Olea europeafruit pulp)
Table 9.4, p. 230-1
8/10/2019 EEB304 LECT16 Oils Spring11
41/52
2005
2007
Traditional Vegetable Oil Plants
8/10/2019 EEB304 LECT16 Oils Spring11
42/52
Traditional Vegetable Oil PlantsLinseed Oil - Flax Sesame Oil
Traditional Oil Crop Olive
8/10/2019 EEB304 LECT16 Oils Spring11
43/52
Traditional Oil Crop - OliveCold Pressing of pulp after seeds removed
extra-virgin first press, low oleic acid levelnot processed further
Traditional Oil Crop Olive
8/10/2019 EEB304 LECT16 Oils Spring11
44/52
Traditional Oil Crop - OliveCold Pressing of pulp after seeds removed
extra-virgin first press, low oleic acid levelnot processed further
virgin first press, higher acid levelnot processed further
Traditional Oil Crop Olive
8/10/2019 EEB304 LECT16 Oils Spring11
45/52
Traditional Oil Crop - OliveCold Pressing of pulp after seeds removed
extra-virgin first press, low oleic acid levelnot processed further
virgin first press, higher acid levelnot processed further
refined refining methods usedodor/flavor altered
pure mixture of refined and virgin oils
Major Oil Crops PalmFigure 9 21 p 240
8/10/2019 EEB304 LECT16 Oils Spring11
46/52
Major Oil Crops - Palm
Vegetable fatsolid at room temp
Palm plantation - Thailand
Figure 9.21, p. 240
8/10/2019 EEB304 LECT16 Oils Spring11
47/52
Major Oil Crops Sunflower
8/10/2019 EEB304 LECT16 Oils Spring11
48/52
Major Oil Crops - Sunflower
Figure 9.12, p. 234
Major Oil Crops Canola
8/10/2019 EEB304 LECT16 Oils Spring11
49/52
Major Oil Crops - CanolaBrassica napusrapeseedrape
Canada: Canadian oil = Canola
V t bl Oil d S
8/10/2019 EEB304 LECT16 Oils Spring11
50/52
Vegetable Oils and Soaps
Hydrolysis of acylglyceridefatty acids + glycerolTriacylglyceride + alkali (e.g. NaOHlye)sodium salt of fatty
acid + glycerol + water
Soap molecules connect oils
with water
Figure 9.5, p. 223
Soaps versus Detergents
8/10/2019 EEB304 LECT16 Oils Spring11
51/52
Soaps versus DetergentsDetergentsformed from hydrocarbons, connected with sulfonic
acid (SO3), a cation, or a non-ionic polar group
Detergents: less harsh than soaps (less strongly basic in pH)
Also their salts are more soluble than those of soapno bathtub ring
Figure 9.5, p. 223
Th d L M di i l Pl
8/10/2019 EEB304 LECT16 Oils Spring11
52/52
Thursday LectureMedicinal Plants
Reading: Textbook, Chapter 11
Recommended