1. Thursday Lecture – Plant Beverages with Caffeine
Reading: Textbook, Chapter 13
In this lecture our attention will turn to plants that have been used to make beverages that are enjoyed widely in part because of their stimulating effect when consumed due to the presence of caffeine or similar compounds.

2. Quiz

3. Quiz
The alkaloid from this New World plant passes into the brain more rapidly than heroine or cocaine and is thus highly addictive – what is the name of the alkaloid and what is the name of the plant?
The world’s most widely used psychoactive drug is caffeine, which is produced by a variety of different plants – name a plant source of caffeine originally native to the New World and one originally native to the Old World.

4. Caffeine and Theobromine – Mild Stimulants
alkaloids (note N, ring structure)
“methylated xanthines”= methylxanthines
caffeine
theobromine

5. Caffeine and Theobromine – Mild Stimulants
alkaloids (note N, ring structure)
“methylated xanthines”= methylxanthines
caffeine
theobromine
Effects of Caffeine:
central nervous system stimulant

6. Caffeine and Theobromine – Mild Stimulants
alkaloids (note N, ring structure)
“methylated xanthines”= methylxanthines
caffeine
theobromine
Effects of Caffeine:
central nervous system stimulant
mild diuretic

7. Caffeine and Theobromine – Mild Stimulants
alkaloids (note N, ring structure)
“methylated xanthines”= methylxanthines
caffeine
theobromine
Effects of Caffeine:
central nervous system stimulant
mild diuretic (makes you go “pee”)

8. Caffeine and Theobromine – Mild Stimulants
alkaloids (note N, ring structure)
“methylated xanthines”= methylxanthines
caffeine
theobromine
Effects of Caffeine:
central nervous system stimulant
mild diuretic
Mode of action:
interferes with enzyme, so that adrenaline remains active  alert feeling

9. Caffeine and Theobromine – Mild Stimulants
alkaloids (note N, ring structure)
“methylated xanthines”= methylxanthines
caffeine
theobromine
Effects of Caffeine:
central nervous system stimulant
mild diuretic
Mode of action:
interferes with enzyme, so that adrenaline remains active  alert feeling
blocks adenosine receptors  inhibits sleep signals

10. Caffeine and Theobromine – Mild Stimulants
alkaloids (note N, ring structure)
“methylated xanthines”= methylxanthines
caffeine
theobromine
Effects of Caffeine:
central nervous system stimulant
mild diuretic
Mode of action:
interferes with enzyme, so that adrenaline remains active  alert feeling
blocks adenosine receptors  inhibits sleep signals
Note: latter activity also interacts with dopamine receptors

11. Health Effects of Caffeine
Most widely used psychoactive drug
small amounts  no long term effects have been noted

12. Health Effects of Caffeine
Most widely used psychoactive drug
small amounts  no long term effects have been noted
even small amounts taken regularly can produce withdrawal if stopped (often manifested as headaches)

13. Health Effects of Caffeine
Most widely used psychoactive drug
small amounts  no long term effects have been noted
even small amounts taken regularly can produce withdrawal if stopped (often manifested as headaches)
large amounts  adverse symptoms such as anxiety, insomnia

14. Health Effects of Caffeine
Most widely used psychoactive drug
small amounts  no long term effects have been noted
even small amounts taken regularly can produce withdrawal if stopped (often manifested as headaches)
large amounts  adverse symptoms such as anxiety, insomnia
dose-dependent, so that effects on young, unborn
NOTE: current recommendations, pregnant women should reduce or eliminate caffeine consumption during pregnancy

15. Health Effects of Caffeine
Most widely used psychoactive drug
small amounts  no long term effects have been noted
even small amounts taken regularly can produce withdrawal if stopped (often manifested as headaches)
large amounts  adverse symptoms such as anxiety, insomnia
dose-dependent, so that effects on young, unborn
NOTE: current recommendations, pregnant women should reduce or eliminate caffeine consumption during pregnancy
- effects on other animals can be different, e.g. dogs, cats, birds

16. Major Plant Sources of Caffeine
Coffee – Coffea arabica and related species
Chocolate – Theobroma cacao
Tea – Camellia sinensis

17. Major Plant Sources of Caffeine
Coffee – Coffea arabica and related species
Chocolate – Theobroma cacao
Tea – Camellia sinensis
Other sources of caffeine:
Mate, Ilex paraguariensis
Guaraná, Paullinia capana
Kola, Cola nitida

18. Tea –Beverage of the World
Camellia sinensis – Theaceae
Shrub, native to China

19. Tea – In the Field Tea Shrubs are grown in large plantations
Picking is done by hand – only the shoot tips are taken

20. Tea – Processing

21. Tea Types
White tea – leaves are dried only; weak

22. Tea Types White tea – leaves are dried only; weak
Green tea – leaves are steamed (destroys fermentation enzymes), dried, and rolled; weak

23. Tea Types White tea – leaves are dried only; weak
Green tea – leaves are steamed (destroys fermentation enzymes), dried, and rolled; weak
Black tea – leaves are withered, rolled, fermented, dried; strong

24. Tea Types White tea – leaves are dried only; weak
Green tea – leaves are steamed (destroys fermentation enzymes), dried, and rolled; weak
Black tea – leaves are withered, rolled, fermented, dried; strong
Oolong tea – intermediate between black and green – short fermentation

25. Food of the Gods Theobroma cacao – Sterculiaceae
Understory tree, native to New World

26. Cacao - the Cauliflorous Tree
Main Varieties:
Criollo (“native”) – best quality, worst yield, worst disease tolerance

27. Cacao - the Cauliflorous Tree
Main Varieties:
Criollo (“native”) – best quality, worst yield, worst disease tolerance
Forastero (“foreign”) – worst quality, best yield, best disease tolerance

28. Cacao - the Cauliflorous Tree
Main Varieties:
Criollo (“native”) – best quality, worst yield, worst disease tolerance
Forastero (“foreign”) – worst quality, best yield, best disease tolerance
Trinitario – hybrid of other two, intermediate in quality, yield, and disease tolerance

29. Cacao - the Cauliflorous Tree

30. Cacao - the Tropical Crop

31. Chocolate Chemistry
Caffeine – less than coffee (chocolate bar 30 mg; cup coffee, 100 mg)
Theobromine – stimulates heart muscle

32. Chocolate Chemistry
Caffeine – less than coffee (chocolate bar 30 mg; cup coffee, 100 mg)
Theobromine – stimulates heart muscle
Phenylethylamine – reputed to be “mood elevator”, antidepressant
- found in brain; low levels linked to depression; chocolate contains low levels of PEA; knowledge of chemistry still incomplete

33. Chocolate Chemistry
Caffeine – less than coffee (chocolate bar 30 mg; cup coffee, 100 mg)
Theobromine – stimulates heart muscle
Phenylethylamine – reputed to be “mood elevator”, antidepressant
- found in brain; low levels linked to depression; chocolate contains low levels of PEA; knowledge of chemistry still incomplete
Chocolate Myths:
chocolate does not cause acne

34. Chocolate Chemistry
Caffeine – less than coffee (chocolate bar 30 mg; cup coffee, 100 mg)
Theobromine – stimulates heart muscle
Phenylethylamine – reputed to be “mood elevator”, antidepressant
- found in brain; low levels linked to depression; chocolate contains low levels of PEA; knowledge of chemistry still incomplete
Chocolate Myths:
chocolate does not cause acne
chocolate is not a trigger for migraines

35. Chocolate Chemistry
Caffeine – less than coffee (chocolate bar 30 mg; cup coffee, 100 mg)
Theobromine – stimulates heart muscle
Phenylethylamine – reputed to be “mood elevator”, antidepressant
- found in brain; low levels linked to depression; chocolate contains low levels of PEA; knowledge of chemistry still incomplete
Chocolate Myths:
chocolate does not cause acne
chocolate is not a trigger for migraines
chocolate is probably not an aphrodisiac

36. Chocolate Chemistry
Caffeine – less than coffee (chocolate bar 30 mg; cup coffee, 100 mg)
Theobromine – stimulates heart muscle
Phenylethylamine – reputed to be “mood elevator”, antidepressant
- found in brain; low levels linked to depression; chocolate contains low levels of PEA; knowledge of chemistry still incomplete
Chocolate Myths:
chocolate does not cause acne
chocolate is not a trigger for migraines
chocolate is probably not an aphrodisiac
NOTE: chocolate “craving” is probably real; reasons, mechanism are unclear

37. Cacao - Processing Seeds are spread out and allowed to ferment
Fermented seeds are dried and roasted
Seed coats are removed
“Nibs” are ground, which produces a thick liquid called chocolate liquor (non-alcoholic)
Chocolate liquor is fed through a high pressure press which separates the fat (cocoa butter) from the solids (cocoa powder)
The cocoa butter and cocoa powder can be recombined together with sugar or milk to produce chocolate

38. Cacao – Processing 2 Notes:
Chocolate liquor is intensely flavored, bitter – diluted with water and flavored it provides a drink – this is how Montezuma and other Aztec royalty would have consumed it, flavored with vanilla and chili pepper

39. Cacao – Processing 2 Notes:
Chocolate liquor is intensely flavored, bitter – diluted with water and flavored it provides a drink – this is how Montezuma and other Aztec royalty would have consumed it, flavored with vanilla and chili pepper
Cocoa powder contains the chocolate flavor – it can be darkened and the flavor intensified by treating with alkalinization = “Dutching”

40. Cacao – Processing 2 Notes:
Chocolate liquor is intensely flavored, bitter – diluted with water and flavored it provides a drink – this is how Montezuma and other Aztec royalty would have consumed it, flavored with vanilla and chili pepper
Cocoa powder contains the chocolate flavor – it can be darkened and the flavor intensified by treating with alkalinization = “Dutching”
Cocoa butter is the fat – it is tasteless but has the distinctive property of melting at about the human body temperature

41. Cacao – Processing 3 Further Notes:
Two other processes are critical to the production of chocolate
Conching – the chocolate is placed in a machine and mixed with steel beads, the heat generated by friction alters the texture of the cocoa/sugar particles. The highest quality chocolate is conched for about 72 hrs, low quality chocolates only for about 4-6 hrs
Tempering – chocolate is heated to enhance the development of crystals of cocoa butter with the proper characteristics: snap rather than crumble and melt at body temperature

42. Chocolate – the Products
Unsweetened: Chocolate liquor + cocoa butter, no sugar
-- mole sauce etc.

43. Chocolate – the Products
Semisweet and bittersweet – sugar added
Unsweetened: Chocolate liquor + cocoa butter, no sugar
-- mole sauce etc.

44. Chocolate – the Products
Semisweet and bittersweet – sugar added
Unsweetened: Chocolate liquor + cocoa butter, no sugar
-- mole sauce etc.
Milk chocoloate – has milk solids + sugar + unsweetened chocolate

45. Coffee – Out of Africa
1. Discovery in Ethiopia (goats, goatherds, goddesses?)

46. Coffee – Out of Africa
s – spread to Europe of coffee drinking

47. Coffee – Out of Africa
s – Dutch plantations in East Indies (“Java”)

48. Coffee – Out of Africa
4. French take (smuggle?) coffee to West Indies (Martinique)

49. Coffee – Out of Africa
5. Coffee production starts in Brazil (now #1 producer)

50. Coffee arabica Coffea – member of Rubiaceae Shrubs Fruit = berry
Pericarp, seed coats removed  seed used

51. This Bean is a Berry
The coffee fruit is a berry, sometimes called a “cherry”
The “bean” is the interior of the seed, with the seed wall removed
Hand-picking selects the best quality fruits

52. Coffee Processing 1. Seeds dried, fermented (chemical fermentation)
2. Seeds roasted (hot air)
3. Seeds ground, brewed

53. Coffee Issues Pollution
- processing of coffee (in beneficios)  large amount of water
Disease
- fungal diseases wiped out coffee production in Sri Lanka (Ceylon)
- fungal diseases still threaten crops in Brazil
Shade vs. sun coffee
- traditionally, coffee grown under shade
 coffee plantations preserve biodiversity
Decaffeination – solvent vs. water extraction
- solvent extraction  caffeine recovered, sold

54. Thursday Lecture – Alcoholic Beverages
Reading: Textbook, Chapter 14
In this lecture our attention will turn to plants that have been used to make beverages that are enjoyed widely in part because of their stimulating effect when consumed due to the presence of caffeine or similar compounds.