The document discusses vegetable oils, which are mostly composed of triglycerides - glycerol bonded to three fatty acid chains. The properties of the fatty acid chains, such as length and saturation, determine the oil's properties. Plants produce oils for energy storage, mostly in seeds. Historically, people consumed oils for energy, but widespread availability and longer lifespans have revealed health issues like heart disease. While saturated fats are linked to disease, polyunsaturated fats can produce carcinogens and monounsaturated fats may be healthiest. Oils are extracted mechanically or with solvents, then processed. Common sources include soybean, corn, and olive oils.

1. An Oli
Abdul Moiz Dota

2. Vegetable Oils
Plant oils – mostly acylglycerides
Glycerol – 3-carbon “backbone”

3. Vegetable Oils
Plant oils – mostly acylglycerides
Glycerol – 3-carbon “backbone”
Acyl groups – mostly fatty acids = chain of carbon atoms

4. Triacylglyceride structure

5. Vegetable Oils
Plant oils – mostly acylglycerides
Glycerol – 3-carbon “backbone”
Acyl groups – mostly fatty acids = chain of carbon atoms
Properties of acyl groups:
1. Length – longer = higher melting point

6. Vegetable Oils
Plant oils – mostly acylglycerides
Glycerol – 3-carbon “backbone”
Acyl groups – mostly fatty acids = chain of carbon atoms
Properties of acyl groups:
1. Length – longer = higher melting point
2. Unsaturation – the presence of double-bonds between carbons

7. Vegetable Oils
Plant oils – mostly acylglycerides
Glycerol – 3-carbon “backbone”
Acyl groups – mostly fatty acids = chain of carbon atoms
Properties of acyl groups:
1. Length – longer = higher melting point
2. Unsaturation – the presence of double-bonds between carbons
- monounsaturated = has 1 double bond

8. Vegetable Oils
Plant oils – mostly acylglycerides
Glycerol – 3-carbon “backbone”
Acyl groups – mostly fatty acids = chain of carbon atoms
Properties of acyl groups:
1. Length – longer = higher melting point
2. Unsaturation – the presence of double-bonds between carbons
- monounsaturated = has 1 double bond
- polyunsaturated = has 2 or more double bonds

9. Vegetable Oils
Plant oils – mostly acylglycerides
Glycerol – 3-carbon “backbone”
Acyl groups – mostly fatty acids = chain of carbon atoms
Properties of acyl groups:
1. Length – longer = higher melting point
2. Unsaturation – the presence of double-bonds between carbons
- monounsaturated = has 1 double bond
- polyunsaturated = has 2 or more double bonds
Double bonds  generally lower melting point of compound

10. Triacylglyceride structure

11. Vegetable Oils – The Plant View
Why do plants produce oils?

12. Vegetable Oils – The Plant View
Why do plants produce oils?
Answer: high energy content (caloric value)  compact way to
store energy

13. Vegetable Oils – The 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?

14. Vegetable Oils – The 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)

15. Vegetable Oils – The Human
View
Why do people consume vegetable oils (and other fats)?

16. Vegetable Oils – The Human
View
Why do people consume vegetable oils (and other fats)?
Answer: high energy content – we retain a craving for fats that
was an advantage for our ancestors at a time when it was difficult
to obtain fats

17. Vegetable Oils – The Human
View
Why do people consume vegetable oils (and other fats)?
Answer: high energy content – we 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

18. Vegetable Oils – The Human
View
Why do people consume vegetable oils (and other fats)?
Answer: high energy content – we 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

19. Acylglycerides – Health Issues –
Consumption Increasing
World Consumption Projected to be up
16% - 1998-2001

20. Acylglycerides – Health Issues –
Consumption Increasing
World Consumption Projected to be up
12% - 2006-2011

21. Acylglycerides – Health Issues
– 25% of deaths in U.S. due to heart disease (2007) - #1 cause

22. Acylglycerides – Health Issues
– 25% of deaths in U.S. due to heart disease (2007) - #1 cause
– Correlation between blood cholesterol & heart disease

23. Acylglycerides – Health 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

24. Acylglycerides – Health 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
– Correlation – saturated dietary fats  arterial plaque formation

25. Acylglycerides – Health 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
– Correlation – saturated dietary fats  arterial plaque formation
Conclusion: exchange saturated for unsaturated fats in foods

26. Acylglycerides – Health 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
– Correlation – saturated dietary fats  arterial plaque formation
Conclusion: exchange saturated for unsaturated fats in foods
Problem: polyunsaturated fats  linked to production of free
radicals, which are carcinogenic
Recommendation: mono-unsaturated fats appear best for health,
based on currently available information

27. Acylglycerides – Health 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
– Correlation – saturated dietary fats  arterial plaque formation
Conclusion: exchange saturated for unsaturated fats in foods
Problem: polyunsaturated fats  linked 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

28. Trans Fats
Saturated fats (animal fats, tropical vegetable fats)  link to
heart disease

29. Trans Fats
Saturated fats (animal fats, tropical vegetable fats)  link to
heart disease
Polyunsaturated fats  vegetable oils, liquid at room temp.

30. Trans Fats
Saturated fats (animal fats, tropical vegetable fats)  link to
heart disease
Polyunsaturated fats  vegetable oils, liquid at room temp.
Hydrogenation – bubble hydrogen gas through vegetable oil,
increases the saturation

31. Trans Fats
Saturated fats (animal fats, tropical vegetable fats)  link to
heart disease
Polyunsaturated fats  vegetable oils, liquid at room temp.
Hydrogenation – bubble hydrogen gas through vegetable oil,
increases the saturation
Completely saturated  hard, like wax – not useful

32. Trans Fats
Saturated fats (animal fats, tropical vegetable fats)  link to
heart disease
Polyunsaturated fats  vegetable oils, liquid at room temp.
Hydrogenation – bubble hydrogen gas through vegetable oil,
increases the saturation
Completely saturated  hard, like wax – not useful
Partial saturation  creamy consistency, useful for spreads
also more chemically stable, longer shelf life

33. Trans Fats
Saturated fats (animal fats, tropical vegetable fats)  link to
heart disease
Polyunsaturated fats  vegetable oils, liquid at room temp.
Hydrogenation – bubble hydrogen gas through vegetable oil,
increases the saturation
Completely saturated  hard, like wax – not useful
Partial saturation  creamy consistency, useful for spreads
also more chemically stable, longer shelf life
Problem – creates trans type of bonds – health problems

34. Omega 3, Omega 6 fats
“Omega n” – refers to position of double bond relative to
methyl end of fatty acid
Required in human diet – omega 3, omega 6 types
Associated with health benefits

35. 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 used – allows
continuous processing and separation of
residual “cake”

36. 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 used – allows
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

37. 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

38. Common Sources of Vegetable Oils
Polyunsaturated
- linseed oil (Linum usitatissimum - seeds)
- tung oil (Aleurites fordii – seeds)
Unsaturated
- Safflower (Carthamus – 1-seeded fruits)
- soybean (Glycine max – seeds)
- sunflower (Helianthus annuus – 1-seeded fruits)
- corn oil (Zea mays – germ)
- sesame oil (Sesamum indicum – seeds)
- cottonseed oil (Gossypium – seeds)
- canola oil (Brassica – seeds)
Moderately saturated
- peanut oil (Arachis hypogaea – seeds)
- olive oil (Olea europea – fruit pulp)

39. 2005
2007

40. Traditional Vegetable Oil Plants
Linseed Oil - Flax
Sesame Oil

41. Traditional Oil Crop - Olive
Cold Pressing of pulp after seeds removed
“extra-virgin” – first press, low oleic acid level – not processed further

42. Traditional Oil Crop - Olive
Cold Pressing of pulp after seeds removed
“extra-virgin” – first press, low oleic acid level – not processed further
“virgin” – first press, higher acid level – not processed further

43. Traditional Oil Crop - Olive
Cold Pressing of pulp after seeds removed
“extra-virgin” – first press, low oleic acid level – not processed further
“virgin” – first press, higher acid level – not processed further
“refined” – refining methods used  odor/flavor altered
“pure” – mixture of refined and virgin oils

44. Major Oil Crops - Palm
Palm plantation - Thailand
Vegetable fat – solid at room temp

45. Major Oil Crops - Soybean

46. Major Oil Crops - Sunflower

47. Major Oil Crops - Canola
Brassica napus – “rapeseed”  rape
Canada: Canadian oil = Canola

48. Vegetable Oils and Soaps
Hydrolysis of acylglyceride  fatty acids + glycerol
Triacylglyceride + alkali (e.g. NaOH – lye)  sodium salt of fatty
acid + glycerol +
water
Soap molecules connect oils
with water

49. Soaps versus Detergents
Detergents – formed 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 soap  no “bathtub ring”

50. Thursday Lecture – Medicinal Plants