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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. 2. 3. 4. 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. BLENDING: Chocolate liquor is blended with the butter → →different types of chocolate. CONCHING: blended chocolate mass is kept liquid by frictional heat → the chocolate mass is stored and heated in tanks. 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 Component Chocolate composition In 100 g of chocolate Plain choc. Nutrients protein 3,2 g lipids 33,5 g carbo60,3 g hydrates pure lecithin 0,3 g theobromin 0,6 g e Mineral substances calcium 20 mg magnesium phosphorus 80 mg 130 mg Trace elements iron 2 mg copper 0,7 mg Milk choc. White choc. 7,6 g 32,3 g 57 g 7,5 g 37 g 52 g 0,3 g 0,2 g 0,3 g -- 220 mg 50 mg 210 mg 250 mg 30 mg 200 mg 0,8 mg 0,4 mg traces traces Vitamins in chocolate Vitamins A B1 B2 C D E 40 IU 0,06 mg 0,06 mg 1,14 mg 50 IU 2,4 mg 300 IU 0,1 mg 0,3 mg 3 mg 70 IU 1,2 mg 220 IU 0,1 mg 0,4 mg 3 mg 15 IU 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