Processing technology of tea công nghệ làm trà

Processing technology of teaQuang H.. Jan 28, 2024 3Contents - General introduction of tea - Flavonoids and other components of tea - Technology of tea products Green, black, Oolong,…tea

Processing technology of tea

Quang H Luong, MSc Department of Food Engineering Faculty of Food Science and Technology Nong Lam University – Ho Chi Minh City

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Contents

- General introduction of tea

- Flavonoids and other components of tea

- Technology of tea products (Green, black, Oolong,…teas)

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History of tea

 Reading of reference materials

 Since 1690, E Kaempfer named the bush “Thea”

sinensis

 In 1753, C Linné named Camellia sinensis

 Camellia sinensis (L.) O Kuntze

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Countries grow tea plant

World tea market share in 2009

Jan 28, 2024 Courtesy: http://www.vietnam-tea.com/overview.html 6

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Tea growing areas of Vietnam

Fig 2 Vietnam and its location

Hà Giang,Tuyên Quang, Cao Bằng, Lạng Sơn Vĩnh Phúc, Phú Thọ, Sơn La, Hòa Bình, Bắc Thái

Nghệ An, Hà Tĩnh, Thanh Hóa

Lâm Đồng, Gia Lai, Kon-tum

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Teas and health benefits

 Tea as a panacea

 Anti-carcinogenic activity

 Lung cancer, prostate cancer, breast cancer, skin cancer; stomach,

pancreatic, oesophageal, and colon cancers

 Anti-inflammatory and anti-microbial properties

 Dental and oral diseases

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Flavonoids and other components in tea

X =

Forms of Catechin

(-)-Catechin: R 1 = R 2 = H (-)-Gallocatechin: R 1 = OH, R 2 = H (-)-Catechin gallate: R 1 = H, R 2 = X (-)-Gallocatechin gallate: R 1 = OH, R 2 = X

X =

(-)-Epi form

(-)-Epicatechin: R 1 = R 2 = H (-)-Epigallocatechin: R 1 = OH, R 2 = H (-)-Epicatechin gallate: R 1 = H, R 2 = X (-)-Epigallocatechin gallate: R 1 = OH, R 2 = X

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Technology of tea products

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Plucking of T-leaves and flushes

Courtesy: http://tea-plucking.blogspot.com/

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Categories of tea

 Based on fermentation level

Unfermented tea (Green tea) Full fermented tea (Black tea) Partly fermented tea (Oolong tea, Pouchong tea)

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Courtesy: http://greentealovers.com/greenteatypeschina.htm

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Courtesy: http://www.cookscorner.net/Tea/Antioxidants.html

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Green tea processing

Tea leaves and flushes

Green tea product

Steaming/Panning

Rolling Packaging

Classification Drying

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Oolong tea processing

Tea leaves and flushes Oolong tea product

Sunned withering Indoor withering Drying

Special rolling Panning

Packaging

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OTD - Black tea processing

Tea leaves and flushes Black tea products

Packaging Withering

Rolling Classification

Drying Fermentation

Flower mixing Flower screening

‘Fresh flower scented tea’

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Soluble powder tea processing

Tea leaves and flushes Rolling/Grinding

Extraction Drying/steaming

Aroma stripping Filtration

Freeze drying Concentration

Spray drying Soluble tea powder

Packaging

Blingding Commercial T-refine

Products from T-catechins

Study on human beings

mechanism, toxic, digest,

dose,…

Trends in studying and developing new products from tea

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T-preservation

Table 2 The effect of packaging vs MC of tea

Types of packaging MC of tea (%)

Glass flask with head-pin 7,5 7,5

Wrap by hands, 2 layers of paper 7,5 12,8

Carton box with T-paper wrapping 7,5 13,8

Control (T without-package) 7,5 14,0

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T-packaging

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End of lecture, continuing slides for reference

Free glutamate in foods

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O

O H

O H H

O H

O H

H O

(-)-Catechin

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O

O H

O H H

O

(-)-Catechin gallate

(-)-Gallocatechin gallate

X =

Các dạng (-)-Catechin

(-)-Catechin: R 1 = R 2 = H (-)-Gallocatechin: R 1 = OH, R 2 = H (-)-Catechin gallate: R 1 = H, R 2 = X (-)-Gallocatechin gallate: R 1 = OH, R 2 = X

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Aroma bamboo rotationer

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Flavonoids in tea

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Jan 28, 2024 Department of Food Engineering, FST, NLU 50