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An OliAbdul Moiz Dota
Vegetable Oils
Plant oils – mostly acylglycerides
Glycerol – 3-carbon “backbone”
Vegetable Oils
Plant oils – mostly acylglycerides
Glycerol – 3-carbon “backbone”
Acyl groups – mostly fatty acids = chain of carbon atoms
Triacylglyceride structure
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
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
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
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
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
Triacylglyceride structure
Vegetable Oils – The Plant View
Why do plants produce oils?
Vegetable Oils – The Plant View
Why do plants produce oils?
Answer: high energy content (caloric value) compact way to store energy
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?
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)
Vegetable Oils – The Human View
Why do people consume vegetable oils (and other fats)?
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
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
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
Acylglycerides – Health Issues – Consumption Increasing
World Consumption Projected to be up 16% - 1998-2001
Acylglycerides – Health Issues – Consumption Increasing
World Consumption Projected to be up 12% - 2006-2011
Acylglycerides – Health Issues
– 25% of deaths in U.S. due to heart disease (2007) - #1 cause
Acylglycerides – Health Issues
– 25% of deaths in U.S. due to heart disease (2007) - #1 cause
– Correlation between blood cholesterol & heart disease
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
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
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
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
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
Trans Fats
Saturated fats (animal fats, tropical vegetable fats) link to heart disease
Trans Fats
Saturated fats (animal fats, tropical vegetable fats) link to heart disease
Polyunsaturated fats vegetable oils, liquid at room temp.
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
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
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
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
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
Extraction of Vegetable OilsBasic 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”
Extraction of Vegetable OilsBasic 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
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
Common Sources of Vegetable OilsPolyunsaturated
- 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)
2005
2007
Traditional Vegetable Oil PlantsLinseed Oil - Flax Sesame Oil
Traditional Oil Crop - OliveCold Pressing of pulp after seeds removed
“extra-virgin” – first press, low oleic acid level – not processed further
Traditional Oil Crop - OliveCold 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
Traditional Oil Crop - OliveCold 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
Major Oil Crops - Palm
Vegetable fat – solid at room temp
Palm plantation - Thailand
Major Oil Crops - Soybean
Major Oil Crops - Sunflower
Major Oil Crops - CanolaBrassica napus – “rapeseed” rape Canada: Canadian oil = Canola
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
Soaps versus DetergentsDetergents – 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”
Thursday Lecture – Medicinal Plants