الفهرس 
Historical background of teaOnly 14 pages are availabe for public view
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Abstract
Lots of people speak about the major importance of tea. The red and green tea are two types in common use in the Egyptian house. Tea is a very popular drink all over the world as the tea leaves are known from a long time in china. It is also popularly known as a global drink, being served to guests in all places as a sign of the honorable confidence in this medical plant. The antioxidants, caffeine, tannate, polyphenol, flavonols, catechin, vitamins like C, E and B2, manganese, zinc, magnesium, phosphorus, selenium, aluminum, amino acids and essential oil were considered good source in tea.
Tea can be used as a nurshing substance accompanied with curing some of the following diseases:
The heart diseases such as agina pectoris, Caffeine is useful especially in curing headache and hypotension, tea helps in digesting food especially fatty substances. It is also useful in curing diarrhea and preventing dehydration.
Therefore, tea is not harmful as we know, but it is a nurshing substances accompanied with drugs for curing diseases.
1 Kg from each green tea and black tea during in 2007 season from the local market in assuit .
The present investigation included the following topics:-
-Determination of the gross chemical composition of black and green teas including moisture, protein, fat, carbohydrates, crude fiber and ash contents.
-Determination of mineral contents including sodium, potassium, magnesium, phosphours, calcium and iron.
-Determination of antioxidants and active substances (polyphenols, caffeine, zinc, aluminum, selenium and vitamin C).
-Determination of blood glucose and hemoglobin in blood serum of the experimental albino rats after feeding with the twelve studied green and black tea treatments as well as in the control diets.
-Determination of the triglycerides, total cholesterol, HDL-cholesterol, LDL-cholesterol in blood serum of the experimental albino rats after feeding with the twelve studied green and black tea treatments as well as in the control diets.
The experiment included (72) males white albino rats (Sprague dawley strain) weighing between (100 and 120 gm) divided into (14) groups and every group included (5) rats. Rats were housed individually in wire cages under the normal laboratory condition and fed on the basal diet for a week as adaptation period. Daily administrations continued for (4) weeks. In the study one group was used as control and was fed the basal diet, including casein (11.36%), salt mixture (4.0%), vitamins mixture (1.0%), corn oil (5.0%) and corn starch (78.64%). Two groups were used ascontrol and diabetic and were fed the basal diet, while the twelve groups were fed on tea treatments as follows:
Group1: Control group was fed on basal diet.
Group2: Diabetic group was fed on basal diet.
Group3: Diabetic group was fed on powder black tea (0.33%).
Group4: Diabetic group was fed on powder black tea (0.66%).
Group5: Diabetic group was fed on powder black tea (0.99%).
Group6: Diabetic group was fed on powder green tea (0.33%).
Group7: Diabetic group was fed on powder green tea (0.66%).
Group8: Diabetic group was fed on powder green tea (0.99%).
Group9: Diabetic group was fed on infusion black tea (0.33%).
Group10: Diabetic group was fed on normal black tea (0.33%).
Group11: Diabetic group was fed on boiled black tea (0.33%).
Group12: Diabetic group was fed on infusion green tea (0.33%).
Group13: Diabetic group was fed on normal green tea (0.33%).
Group14: Diabetic group was fed on boiled green tea (0.33%).
Moreover, by the end of the feeding experiment, feed intake, body weight gain of experimental rats during the experiment were estimated.
Blood samples were collected from the retro orbital sinus under eye rat in a clean sterile centrifuge tube by the end of feeding experiment. Samples were tightly kept in sealed aliquot tubes at -20 C until biochemical assays.
weighed separately and immersed in (10%) neutral buffered formaline until histopathological tests were carried out.
Results could be summarized as follows:
1- The moisture content of the four studied black tea treatments were (7.00%, 4.10 %, 6.50 % and 5.40 %) for powder, boiled, infusion and normal teas. While green tea treatments were (7.80 %, 4.50 %, 7.10 % and 6.40 %); respectively calculated on dry weight basis.
2- The ash content of the four studied black tea treatments were (7.20 %, 4.90 %, 6.80 % and 6.40 %). While green tea treatments were (6.50 %, 4.80 %, 6.70 % and 4.10 %) for powder, boiled, infusion and normal teas; respectively calculated on dry weight basis.
3- The carbohydrate content of the four studied black tea treatments were (45.00 %, 54.70 %, 53.90 % and 52.20 %). While green tea treatments were (44.20 %, 53.30%, 52.40% and 48.90%) for powder, boiled, infusion and normal teas; respectively calculated on dry weight basis.
4- The crude fiber content of the four studied black tea treatments were (17.00%, 14.50%, 14.80% and 14.60%). While green tea treatments were (19.80%, 14.90%, 17.20% and 15.80%) for powder, boiled, infusion and normal teas; respectively calculated on dry weight basis.
5- The crude fat content of the four studied black tea treatments were (2.00%, 1.20%, 1.40% and 1.50%). While green tea treatments were (3.50%, 1.40%, 2.10% and 1.30%) for powder, boiled, infusion and normal teas; respectively calculated on dry weight basis.
6- The protein content of the four black tea treatments was (28.80%, 24.70%, 23.10% and 25.30%). While green treatments were (26.00%, 25.60%, 21.60% and 29.90%) for powder, boiled, infusion and normal teas; respectively calculated on dry weight basis.
7- The mineral content (calcium, magnesium, sodium) of the four studied black tea treatments were ( 2.67 mg/100g, 0.00, 0.60 mg /100g and1.70 mg /100g ), ( 1.16 mg /100g, 0.50 mg /100g, 0.90 mg /100g and 0.60 mg /100g) and ( 0.15 mg /100g, 0.05 mg /100g, 0.08 mg /100g and 0.07 mg /100g) for powder, boiled, infusion and normal teas; respectively on dry weight basis. While green treatments values were (1.90 mg/100g, 0.50 mg /100g, 0.80 mg /100g and 1.30 mg /100g), (1.30 mg /100g, 0.70 mg/100g, 1.10 mg /100g and 1.00 mg /100g) and (0.13 mg /100g, 0.06 mg /100g, 0.08 mg /100g and 0.09 mg /100g).
8- The mineral content (phosphorus, potasium and iron) of the four studied black tea treatments were (0.18 mg /100g, 0.06 mg/100g, 0.06 mg /100g and 0.08 mg/100g), ( 3.16 mg /100g, 0.60 mg /100g, 1.00 mg /100g and 2.60 mg /100g) and ( 0.10 mg /100g, 0.01 mg /100g, 0.03 mg /100g and 0.04 mg /100g) for powder, boiled, infusion and normal teas; respectively. While green treatments values were (0.79 mg /100g, 0.05 mg /100g, 0.50 mg /100g and 0.60 mg /100g), (3.40 mg/100g, 2.60 mg/100g, 3.50 mg/100g and 1.90 mg/100g) and (0.20 mg/100g, 0.02 mg /100g, 0.08 mg /100g and 0.02 mg /100g) for powder, boiled, infusion and normal; respectively calculated on dry weight basis.
9- The antioxidants content (caffeine, total polyphenols and vitamin C) of the four black tea treatments were (2.20%, 1.50%, 1.20% and 1.70 %), (11.49%, 2.30%, 12.00% and 10.00 %) and ( 7.50%, 0.50%, 5.00% and 3.00 %). While green treatments values were (1.46%, 1.30%, 1.00% and 0.90%), (10.57%, 4.00%, 13.50% and 12.30%) and (2.80%, 0.70%, 1.90% and 1.20%) for powder, boiled, infusion and normal teas; respectively calculated on dry weight basis.
10- The antioxidants minerals content (aluminum, selinum and zinc) of the four black tea treatments were (0.37 mg /100g, 0.02 mg /100g, 0.15 mg /100g and 0.30 mg /100g), (0.40 mg /100g, 0.12 mg /100g, 0.50 mg /100g and 0.25 mg/100g) and (3.10 mg /100g, 1.00 mg /100g, 1.50 mg /100g and 2.20 mg/100g). While green treatments values were (0.32 mg /100g, 0.31 mg /100g, 0.10 mg /100g and 0.21 mg /100g), (0.50 mg /100g, 0.21 mg /100g, 0.70 mg /100g and 0.10 mg /100g) and ( 3.43 mg /100g, 1.20 mg /100g, 2.90 mg /100g and 1.80 mg /100g) for powder, boiled, infusion and normal teas; respectively calculated on dry weight basis.
1-Groups of tea treatments:
1- There were no significant differences among all (14) studied groups of the experimental rats in feed intake.
2- There were significant differences among all (14) studied groups of the experimental rats in body weight gain at (p<0.05). However, the most effective group in decreasing body weight gain was diabetic group fed on normal green tea recording (150.0± 2.89) gm /rat. While the highest increment value was observed for group diabetic group fed on infusion black tea recording (190.30± 2.45 gm/rat).
3- There were significant differences among all (14) studied groups in the blood serum glucose at (p<0.05). The most effective group in decreasing blood serum glucose in the experimental animals was infusion green tea recording (91.40±1.89) mg /dl decrement by the end of feeding experimental. However, the least decrement value was observed in diabetic group fed on powder black tea 0.99% was recording (95.50+_0.84) mg / dl.
4- There were significant differences among all (14) studied groups in serum triglycerides at (p<0.05). The least decrement value was observed in diabetic group fed on infusion green tea recording (122.50±1.44mg/dl) and in diabetic group fed on normal black tea recording (122.60±0.26 mg/dl). However, the highest triglyceride value was recorded for diabetic group fed on the normal green tea (143.50±0.98mg/dl).
5- There were significant difference among all (14) studied groups in serum total cholesterol at (p<0.05).The most effective group in decreasing blood serum total cholesterol in the experimental animals was infusion green tea recording (95.1±0.49 mg /dl) decrement by the end of feeding experimental. However, the least decrement value was observed in diabetic group fed on powder black tea 0.99% recorded (121.00±4.01).
6- There were significant differences among all (14) studied groups in serum HDL-cholesterol. Diabetic group fed on infusion green tea recorded an increase in blood serum HDL of the experimental animals (95.50±0.64mg /dl) by the end of feeding experiment. However, the least increment value was observed for diabetic group fed on powder black tea 0.99% recorded (60.15±0.26mg/dl).
7- There were significant differences between (14) studied groups in serum LDL-cholesterol. Diabetic group fed on basal diet recorded 21.71± 0.74 mg /dl in blood serum LDL of the experimental animals. However, the highest rate of decrement was observed for diabetic group fed on normal black tea recording 1.82±0.67 mg /dl. Besides, the worest group was recorded for diabetic group fed on powder green tea 0.33% which had the value (28.94± 0.69mg/dl).
8- There were significant differences between (14) studied groups in serum hemoglobin at (p<0.05). Diabetic group fed on powder black tea 0.33% recorded (1.44±0.218 g/dl) having the least rate of decrement in blood serum hemoglobin of the experimental animals. However, the highest rate of increment was observed for diabetic group fed on infusion green tea recording 13.50±1.56 g / dl .
9- There were significant differences among groups at (p<0.01) in the relative weight of liver. However, the means of group (2) diabetic fed on basal diet and group(5) diabetic group fed on powder black tea 0.99% (2.40±0.50g); respectively. However, diabetic group fed on infusion green tea recorded highest values 3.75± 0.09 gm in the relative weight of liver.
10-There were significant differences among groups at (p<0.01) in the relative weight of kidney. However, the means of diabetic fed on powder black tea 0.99% recorded lowest values in relative weight of kidney compared with the normal rats (0.71±0.02 gm). However diabetic fed on normal and infusion green tea recorded highest values (0.85± 0.23 gm and (0.85±0.13); respectively.
11-There were significant differences among groups at (p<0.01) in the relative weight of pancreas.However, the means of diabetic fed on basal diet recorded lowest values in relative weight of pancreas compared with the normal rats 0.36±0.02 gm. However diabetic fed on infusion green tea recorded highest values (0.58± 0.08 gm) in the relative weight of pancreas.
In Conculation it Could be recommended that
1- Water quality affects tea taste aroma, as well as health conditions.Using purified water rather than tap water or natural water, could improve the quality of tea infusion owing to different elements and minerals matter contents.
2-Tea polyphenols, amino acids, saccharides, vitamins, caffeine and minerals are the main factors which influence the quality of tea infusion. So there may be certain relationships between water quality and the extractions of tea polyphenols, amino acids, saccharides, caffeine and other components.
3- Green tea is rich in quality components and therefore is considered the best kind of teas for cardiovascular, diabetic, hypertensive and atheroclrosis patients.
4- It is not recommended to drink both boiled green and black teas due to their negative beneficials effect of the above-mentioned patients.
5- Tea should not be stored for long periods because the decrease in the quality parameters with the long storage period.