Thursday Lecture –Vegetable Oils and Waxes Reading: Textbook, Chapter 9

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 Anacardiaceae – some people exhibit allergic reaction

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 originally native?

Vegetable Oils Plant oils – mostly acylglycerides Glycerol – 3-carbon “backbone” Figure 9.3, p. 221

Vegetable Oils Plant oils – mostly acylglycerides Glycerol – 3-carbon “backbone” Acyl groups – mostly fatty acids = chain of carbon atoms Figure 9.3, p. 221

Triacylglyceride structure Figure 9.3, p. 221

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 Figure 9.3, p. 221

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 Figure 9.3, p. 221

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 Figure 9.3, p. 221

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 Figure 9.3, p. 221

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 Figure 9.3, p. 221

Triacylglyceride structure Figure 9.3, p. 221

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)? Box 9.1, p. 222

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 Box 9.1, p. 222

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 Box 9.1, p. 222

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 Box 9.1, p. 222

Acylglycerides – Health Issues – Consumption Increasing World Consumption Projected to be up 16% Figure 9.2, p. 220

Acylglycerides – Health Issues – Consumption Increasing World Consumption Projected to be up 12% Figure 9.2, p. 220

Acylglycerides – Health Issues – 25% of deaths in U.S. due to heart disease (2007) - #1 cause Box 9.1, p. 222

Acylglycerides – Health 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

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 Box 9.1, p. 222

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 Box 9.1, p. 222

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 Box 9.1, p. 222

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 Box 9.1, p. 222

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 Box 9.1, p. 222

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 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” Figure 9.6, 9.7, p. 227

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 Figure 9.6, 9.7, p. 227

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

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) Table 9.4, p

Traditional Vegetable Oil Plants Linseed Oil - Flax Sesame Oil

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

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

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

Major Oil Crops - Palm Vegetable fat – solid at room temp Palm plantation - Thailand Figure 9.21, p. 240

Major Oil Crops - Soybean

Major Oil Crops - Sunflower Figure 9.12, p. 234

Major Oil Crops - Canola Brassica 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 Figure 9.5, p. 223

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” Figure 9.5, p. 223

Thursday Lecture – Medicinal Plants Reading: Textbook, Chapter 11