Current LectureAGRI 116 1nd Edition Lecture 16 Outline of Last Lecture I. Chemistry/Biology of SugarII. Sugarcane: History, Biology, involvement in triangle trade/slaveryOutline of Current Lecture II. Tea BiologyIII. Types of TeaIV. American tea lore (if time remains)Current LectureTea BiologyScientific name (Camellia sinensis)– Previously Thea sinensis or (older) Camellia japonica– Thea Sinensis or Camellia japonica– Evergreen shrub/treeTea VarietiesChina Tea (Camellia sinensis var. sinensis)– First tea to be discovered and cultivated– Considered a bush (multi-stemmed)– Small leaves (2-4”ish)– Better adapted to cool climates– Overall lower yieldAssam Tea (Camellia sinensis var. assamica)– Considered a tree– Less resistant to cold– Longer leaves (10”ish)– Higher yieldsBoth can produce white, green, oolong, black, and other types of tea…all a matter of tradition/preference.Center of OriginTwo Centers of Origin?These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.– Morphological evidence says PROBABLY!o Short vs. Long Leaveso Multi vs. Single Stemmed Plantso Yield Differences– HOWEVER, Current research says NO!o Same Chromosome number 2n=30o Easy Hybridizationo Spontaneous Intermediate HybridsAt or near the intersection of latitude 29°N and longitude 98°E (Mondal, 2007)Qianjiazhai, Yunnan Province– Near center of origin for tea– Home of the oldest uncultivated tea tree on Eartho 2700 years old (1996)But wait …Fengqing, Yunnan Province– New record holder of the oldest uncultivated tea tree on Eartho 3200 years old (2007) Types of Tea and Tea HealthTea health - PolyphenolsPolyphenols  Antioxidant propertiesPolyphenols (Types)– Catechins– 25% of the dry weight of a fresh tea leaf– Catechin concentration is greatest in fresh, unbroken and unfermented tea leaves– Tannins (up to 50% of dry weight)o Known to have anti-inflammatory, antibacterial, antiviral, and antiparasitic effectso Shown to inhibit replication of the HIV virus in lab studies Note: Tannins are not the same thing as tannic acidIf you break/crush/twist tea leaves the tannins are released– More astringency (“puckery”)Tulsi (Tulasi) tea: Ocimum tenuiflorumRelated to mint (Lamiaceae family)– Not Camellia sp (china/assam tea group)Cultivated for medicinal/religious purposes– Mainly in India and those practicing HinduismFermentation??In the Tea industry: Oxidation = FermentationTea, coffee, cocoa, kola nuts, and vanilla pods are fermented– Enzymatic, chemical alteration of several compounds in the fruit, seed, or leaves– Starch turned to sugar, leaves turn darker, tannins releasedIt is NOT the same as alcohol fermentation of sugars by microorganisms  an anaerobic processBlack Tea– Wither for 24 hours to reduce water and start the fermentation process– Twist or crush leaves to rupture cells– Dry (fire) to stop fermentation and remove water– USUALLY Assam tea usedOolong TeaBetween green and black in oxidation– 10-70% oxidation (fermentation)Two ways to process– Rolled– Pressed into a ball-like form– Pressed similarly to gunpowder teaGreen Tea– Very little witheringo Leaves are shredded, rolled and immediately heated to stop oxidation– High levels of polyphenols– USUALLY China tea usedWhite Tea– Young leaves (new growth buds)– No oxidation (fermentation)– Higher catechin levels than any other type of teao Arguably “healthier” than green