Chemistry of chocolate

Barbora Ürgeová

Petra Vrchovecká

History of chocolate

900 B. C.: Maya – chocolate drink 16th century: chocolate brought to

Europe by Spanish explorers 1657: first chocolate shop in

London 18th century: chocolate

manufactured in USA 19th century: Peter of Vevey

(Switzerland) perfected process of making milk chocolate

Process of making

1. HARVESTING: The cacao pods from the cacao tree are crushed and left to ferment → drying cacao beans from the pods → beans are roasted, graded and ground → cocoa butter is removed from chocolate liquor.

2. BLENDING: Chocolate liquor is blended with the butter → →different types of chocolate.

3. CONCHING: blended chocolate mass is kept liquid by frictional heat → the chocolate mass is stored and heated in tanks.

4. TEMPERING: the mass is cooled in stages → the mass is rewarmed followed by cooling down.

Kinds of chocolate UNSWEETED CHOCOLATE =

ground roasted chocolate beans with no other added ingredients

SEMI-SWEET CHOCOLATE =

a dark chocolate with lower sugar content

WHITE CHOCOLATE = a confection based on cocoa butter without the cocoa solids

Chocolate composition

In 100 g of chocolate

Component

Plain choc.

Milk choc.

White choc.Nutrients

protein 3,2 g 7,6 g 7,5 g lipids 33,5

g 32,3 g

37 g carbo-hydrates

60,3 g

57 g 52 g

pure lecithin

0,3 g 0,3 g

0,3 g theobromine

0,6 g 0,2 g

--Mineral substances calcium

20 mg

220 mg

250 mg

magnesium

80 mg

50 mg

30 mg phosphoru

s 130 mg

210 mg

200 mg

Trace elements iron 2 mg

0,8 mg

traces copper

0,7 mg

0,4 mg

traces

Vitamins in chocolateVitamins A

40 IU

300 IU

220 IU B1

0,06 mg

0,1 mg

0,1 mg B2

0,06 mg

0,3 mg 0,4 mg C

1,14 mg

3 mg

3 mg D

50 IU

70 IU

15 IU E

2,4 mg 1,2 mg

traces

Theobromine Alkaloid found in cocoa

beans and chocolate Used in medicine as

diuretic, vasodilator, and myocardial stimulant.

Chemically related to caffeine (methylxanthine family)

Mild, lasting stimulant with a mood improving effect

Caffeine

Very small amounts in chocolate

Different properties and effects as theobromine

Strong effect on CNS

Increases alertness

Psychological effects of chocolate Lethal toxicity for animals

- theobromine in chocolate is toxic-animals are unable to metabolize the chemical effectively → epileptic seizures, hearts attacks, internal bleeding

Health benefits for humans- flavonids and gallic acid help protect blood vessels, cardiac health and prevent cancer- it also has been demonstrated to counteract mild hypertension

Thank you for your attention

Sources: www.answers.com/chocolate www.erowid.org/chemicals/ chocolate/chocolate_chemistry www.chocolat.ch/chocsuisscomp.htm chemistry.about.com/library/weekly/aa090301a.htm

Dictionary harvest – sklizeň, žně cacao pod – kakaový lusk blend – míchat trace elements – stopové prvky alertness – bdělost seizure – záchvat cancer – rakovina