Tea chemistry  Barbora Klanicová  Tomáš Fójcik

Some facts about tea  The plant is called Camellia sinensis  Is grown in 30 countries and consumed worldwide  3 basic forms : green tea black tea oolong black tea oolong

Cultivation of tea  Normal height about 1 metre  Tea requires ▪ abundant rainfall and sunshine ▪ acid soil ▪ acid soil ▪ high altitude from sea level to about 2000 m ▪ high altitude from sea level to about 2000 m

Tea manufacture  Processing - cut, tear and curl  Fermentation - process of oxidation  Drying - to arrest fermentation  Sorting - cleaning and grading over electrostatic fibre extractors  Packing - into paper sacks for export

Tea chemistry Caffein Chlorophyll Caffein Chlorophyll  Tea contains Mn, Zn, K, Mg and no carbohydrates or fats  Is rich in fluoride (green tea twice more than black tea)  Caffein ▪ soluble in boiling water ▪ one cup 40 mg ( less than half in a cup of coffee)  Chlorophyll ▪ undergoes biological decomposition ▪ same sort of parent structure as hemoglobin (Fe x Mg)

Tea chemistry  Polyphenols ▪ carbon, oxygen, hydrogen ▪ dull weather-lower concentration When tea leaves are ruptured during rolling, the polyphenols and oxidase mix and oxidation starts if oxygen is present.

Tea and health Scientific Research on Black Tea has revealed that It enhances muscle performance It reduces gastric ulcer It reduces the blood sugar level in diabetes It modulates blood cholesterol Prevention of dental caries by tea or tea polyphenols Tea plant root extract has anti-tumor activity Antioxidant potential of tea Tea polyphenols decrease the mutagenicity of carcinogens It enhances muscle performance It reduces gastric ulcer It reduces the blood sugar level in diabetes It modulates blood cholesterol Prevention of dental caries by tea or tea polyphenols Tea plant root extract has anti-tumor activity Antioxidant potential of tea Tea polyphenols decrease the mutagenicity of carcinogens

Vocabulary abundant rainfall – vydatný déšť high altitude – nadmořská výška grading – třídění soluble in boiling water – rozpustný enhance – zvyšovat gastric ulcer – žaludeční vřed dental caries – zubní kaz

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