pharmacognosy

COFFEECoffee is a brewed beverage with a dark, slightly acidic flavor prepared from the roasted seeds of the coffee plant, colloquially called coffee beans. The beans are found in coffee cherries, which grow on trees.

BOTANICAL NAME: Coffea canephora.

Coffea arabica.

FAMILY: Rubiaceae

COMMON NAME: Coffee

PART USED: Fruit or bean

HABITATE: Southeast Asia, America, Eastern Africa, Tropical

areas.

MORPHOLOGY:

They are evergreen shrubs or small trees that may grow 5 m (15 ft) tall when unpruned.

LEAVES: The leaves are dark green and glossy, usually 10–15 cm (4–6 in) long and 6 cm (2.4 in)

wide.

FLOWERS AND BERRIES: The flowers are axillary, and clusters of fragrant white flowers bloom simultaneously and are followed by oval berries of about 1.5 cm (0.6 in). Green when immature, they ripen to yellow, then crimson, before turning black on drying. Each berry usually contains two seeds, but 5–10% of the berries have only one; these are called peaberries. Berries ripen in seven to nine months.

Cultivation

C. arabica takes about seven years to mature fully, and does best with 1.0–1.5 meters (about 40–59 inches) of rain, evenly distributed throughout the year. It is usually cultivated between 1,300 and 1,500 m altitude, but there are plantations as low as sea level and as high as 2,800 m. The plant can tolerate low temperatures, but not frost, and it does best when the temperature hovers around 20 °C (68 °F). Commercial cultivars mostly only grow to about 5 m, and are frequently trimmed as low as 2 m to facilitate harvesting. Unlike Coffea canephora, C. arabica prefers to be grown in light shade.

PRODUCTION:

ProcessingCoffee berries and their seeds undergo several processes before they become the familiar roasted coffee. Berries have been traditionally selectively picked by hand; a labor intensive method, it involves

the selection of only the berries at the peak of ripeness. More commonly, crops are strip picked, where all berries are harvested simultaneously regardless of ripeness by person or machine. After picking, green coffee is processed by one of two methods—the dry process method, simpler and less labor intensive as the berries can be strip picked, and the wet process method, which incorporates fermentation into the process and yields a mild coffee.

Then they are sorted by ripeness and color and the flesh of the berry is removed, usually by machine, and the seeds—usually called beans—are fermented to remove the slimy layer of mucilage still present on the bean. When the fermentation is finished, the beans are washed with large quantities of fresh water to remove the fermentation residue, which generates massive amounts of coffee wastewater. Finally, the seeds are dried.

Roasting:

The next step in the process is the roasting of the green coffee. Coffee is usually sold in a roasted state, and with rare exceptions all coffee is roasted before it is consumed. It can be sold roasted by the supplier, or it can be home roasted. The roasting process influences the taste of the beverage by changing the coffee bean both physically and chemically. The bean decreases in weight as moisture is lost and increases in volume, causing it to become less dense. The density of the bean also influences the strength of the coffee and requirements for packaging.

Grading the roasted beans

Depending on the color of the roasted beans as perceived by the human eye, they will be labeled as light, medium light, medium, medium dark, dark, or very dark. A more accurate method of discerning the degree of roast involves measuring the reflected light from roasted beans illuminated with a light source in the near infrared spectrum. This elaborate light meter uses a process known as spectroscopy to return a number that consistently indicates the roasted coffee's relative degree of roast or flavor development.

Storage

Once roasted, coffee beans must be stored properly to preserve the fresh taste of the bean. Ideally, the container must be airtight and kept in a cool, dry and dark place. In order of importance: air, moisture, heat, and light are the environmental factors responsible for deteriorating flavor in coffee beans.

CHEMICAL CONSTITUENTS:

Coffee chemistry

Coffee, like all plants, contains thousands of chemical components, all with different characteristics. Although coffee is one of the most studied plants, still many components remain undetected and little is known about the effects on humans of the majority of the substances present in the coffee been and the coffee that we drink.

Many chemical compounds have been identified in coffee beans and these compounds react and interact at all stages of coffee processing to produce a final product with an even greater diversity and complexity of structures. Coffea arabica and Coffea canephora, Robusta, are qualitatively and quantitatively different in chemical composition as shown in the table below

Main constituents of green coffee (% dry matter) :

Constituent Arabica Robusta

Caffeine and trace of purines 1.2 2.2

Trigonelline 1.0 0.7

Total amino acids 10.3 10.3

of which free 0.5 0.8

Carbohydrates 56.9 60.8

Aliphatic acids 1.7 1.6

Lipids 16.0 10.0

Glycosides 0.2 Traces

Minerals 4.2 4.4

Potassium 1.7 1.8

All the constituents that are present in the coffee bean are transformed during roasting, and a large variety of compounds can be extracted and found in the coffee infusions. Some constituents

of coffee beans can be destroyed during roasting, giving new compounds present in the brews or volatile substances .

Health effects of coffee

The health effects of coffee have been studied to determine how coffee drinking affects humans. Coffee contains several compounds which are known to affect human body chemistry.

Some benefits of coffee are as follows:

1. Reduced risk of Alzheimer's disease and Dementia.

2. Reduced risk of gallstone disease

3. Reduced risk of Parkinson's disease

4. Analgesic enhancement

5. Coffee intake may reduce one's risk of diabetes mellitus type 2 by up to half.

6. Coffee can also reduce the incidence of cirrhosis of the liver and has been linked to a reduced risk of hepatocellular carcinoma.

7. Coffee consumption is also correlated to a reduced risk of oral, esophageal, and pharyngeal cancer.

8. Coffee moderately reduces the incidence of dying from cardiovascular disease.

9. Coffee is also a powerful stimulant for peristalsis and is sometimes considered to prevent constipation.

10. The tannins in coffee may reduce the cariogenic potential of foods.

11. Coffee consumption decreased risk of gout in men over age 40.

HARMFUL EFFECTS OF COFFEE:

1. Over 1,000 chemicals have been reported in roasted coffee, and 19 are known rodent carcinogens.

2. Coffee can damage the lining of the gastrointestinal organs, causing gastritis and ulcers.

3. Many coffee drinkers are familiar with "coffee jitters", a nervous condition that occurs when one has had too much caffeine. It can also cause anxiety and irritability.

4. Caffeine has previously been implicated in increasing the risk of high blood pressure;

5. Caffeine molecules are small enough to penetrate the placenta and slip into the baby's blood circulation. Unlike adults, organs and systems in fetuses are not full-fledged, therefore not capable of fully metabolizing caffeine and excreting it.

6. Coffee consumption can lead to iron deficiency anemia in mothers and infants.

7. A study has shown that cafestol, a substance which is present in boiled coffee drinks, dramatically increases cholesterol levels, especially in women.

TEA

BOTNICAL NAME: Camellia sinensis

COMMON NAME: CHAY OR TEA PLANT

FAMILY: THEACEA

PART USED: DRID LEAVES

Camellia sinensis is the species of plant whose leaves and leaf buds are used to produce Chinese tea. It is of the genus Camellia (Chinese: 茶花; pinyin: Cháhuā), a genus of flowering plants in the family Theaceae. White tea, green tea, oolong, pu-erh tea and black tea are all harvested from this species, but are processed differently to attain different levels of oxidation. Kukicha (twig tea) is also harvested from Camellia sinensis, but uses twigs and stems rather than leaves. Common names include tea plant, tea tree, and tea shrub.

Nomenclature and taxonomy

The name sinensis means Chinese in Latin. Camellia is taken from the Latinized name of Rev. Georg Kamel, S.J. (1661–1706), a Czech-born Jesuit priest who became both a prominent botanist and a missionary to the Philippines. Though Kamel did not discover or name the plant, Carl Linnaeus chose his name for the genus to honor Kamel's contributions to science. Older names for the tea plant include Thea bohea, Thea sinensis and Thea viridis.

Description

Chinese Camellia sinensis is native to mainland China, South and Southeast Asia, but it is today cultivated across the world in tropical and subtropical regions. It is an evergreen shrub or small tree that is usually trimmed to below two metres (six feet) when cultivated for its leaves. It has a strong taproot. The flowers are yellow-white, 2.5–4 cm in diameter, with 7 to 8 petals.

The seeds of Camellia sinensis and Camellia oleifera can be pressed to yield tea oil, a sweetish seasoning and cooking oil that should not be confused with tea tree oil, an essential oil that is used for medical and cosmetic purposes, and originates from the leaves of a different plant.

Camellia sinensis plant, with cross-section of the flower (lower left) and seeds (lower right).

MORPHOLOGY

The leaves are 4–15 cm long and 2–5 cm broad. Fresh leaves contain about 4% caffeine. The young, light green leaves are preferably harvested for tea production; they have short white hairs on the underside. Older leaves are deeper green. Different leaf ages produce differing tea qualities, since their chemical compositions are different. Usually, the tip (bud) and the first two

to three leaves are harvested for processing. This hand picking is repeated every one to two

weeks.

Cultivation

Camellia sinensis is mainly cultivated in tropical and subtropical climates, in areas with at least 127 cm. (50 inches) of rainfall a year. However, the clonal one is commercially cultivated from the equator to as far north as Cornwall on the UK mainland .Many high quality teas are grown at high elevations, up to 1500 meters (5,000 ft), as the plants grow more slowly and acquire a better flavour

Tea plants will grow into a tree if left undisturbed, but cultivated plants are pruned to waist height for ease of plucking. Two principal varieties are used, the small-leaved Chinese variety plant (C. sinensis sinensis) and the large-leaved Assamese plant (C. sinensis assamica), used mainly for black tea.

CHEMICAL CONSTITUENTS:

Tea contains the following constituents:

1. Catechins 2. Theanine

3. Caffeine 4. Theophylline

5. Theobromine 6. Phenolic acids.

7. Gallic acids 8. Theanine

9. catechins 10. Theaflavins

Medical uses

HEALTH EFFECTS OF TEA:

1. Green tea catechins have also been shown to possess antibiotic properties due to their role in disrupting a specific stage of the bacterial DNA replication process.

2. Green tea protects against a range of cancers, including lung, prostate and breast cancer.

3. Green tea raises metabolic rates, speeds up fat oxidation and improves insulin sensitivity and glucose tolerance.

4.There is also epidemiological evidence that drinking green tea and black tea may help prevent diabetes.

5. The amino acid L-theanine, found almost exclusively in the tea plant, and in the highest doses in green tea, actively alters the attention networks of the brain.

6. Theanine may help the body's immune system response when fighting infection, by boosting the disease-fighting capacity of gamma delta T cells.

7. 2 cups of green tea a day had a 50 percent lower chance of having cognitive impairment, in comparison to those who drank fewer than 2 cups a day, or who consumed other tested beverages.

8. Drinking black tea can lead to lower levels of the stress hormone cortisol after a stressful event.

9. Epigallocatechin gallate (EGCG) found in green tea can lead to the inhibition of HIV binding and may be used as a complementary therapy for HIV patients.

10. Green tea and its extract have been shown to fight obesity and lower LDL "bad" cholesterol—two risk factors for heart disease and diabetes.

HARMFUL EFFECTS OF TEA:

1. All tea leaves contain fluoride; High fluoride intake (daily intakes over 2 mg for children, 4 mg adults) increases the risk of osteofluorosis and fractures.

2. Caffeine is an addictive drug and overuse of tea may result in harmful side effects, such as an increased likelihood of certain sleep disorders.

3. Tea contains oxalate, overconsumption of which can cause kidney stones, as well as binding with free calcium in the body; other minerals may be bound as well.

4. It has been suggested that chemicals known as tannins present in tea may increase one's risk of esophageal cancer.

5. Hot tea consumption has been linked to a higher risk for esophageal cancer.

6. Consumption of some forms of tea has the potential to result in acute liver damage in some individuals.