Phytochemicals and Quality of Green and Black Teas from Different Clones of Tea Plant

Abstract

Tea is a popular drink with refreshing and functional properties. Bud, 1st leaf, and 2nd leaf of five varieties of tea clones (Gumti Takda-78, Ambari, Chiniya, and Tinali, which are popular in tea plantation area of Nepal) were collected and used for preparing green and orthodox black tea to study antioxidant activity, phytochemicals profile, chemical content, and sensory parameters. One or two leaves were hand-plucked from each bush to get a sample of about 100 leaves and processed for green and orthodox black tea for different clones of tea plants. Phytochemicals, antioxidant activity, and caffeine content were found higher in bud followed by 1st leaf and 2nd leaf for all clones of tea plants. Both types of tea (green and black) from Gumti were significantly (p<0.05) higher having tannin content, flavonoid content, total polyphenol content, caffeine content, and IC50 value of 49.15 and 36.23 (mg GAE/g dry extract), 358.9 and 350.4 (mg QE/g dry extract), 590.5 and 570 (mg GAE/g dry extract), 2.85 and 2.94%, and 45.15 & 51.88 μg/mL, respectively. Green and orthodox tea from Takda-78 was found higher in caffeine content and the least in Tinali for both types of tea. Moisture, water extract, total ash, acid-insoluble ash, and crude fiber content in tea (green and black) from Gumti were found to be 5.4% & 5.37%, 65.89% & 71.46%, 5.524% & 6.52%, 0.46% & 0.57%, and 7.96% & 10.27%, respectively. The ratio of theaflavin and thearubigin (TF : TR) was found 1 : 8.61, 1 : 9.36, 1 : 9.70, 1 : 12.87, and 1 : 6.36 in Takda-78, Ambari, Gumti, Chiniya, and Tinali respectively. The total quality score in green tea (85.13%) and black tea (85.78%) from Gumti was significantly higher than others. Phytochemicals and antioxidant properties of green tea were significantly (p<0.05) higher than those of orthodox black tea for all clones of tea plant. This study suggests Gumti variety to be used in green and orthodox black tea processing for higher phytochemical, chemical, sensory quality, and antioxidant activity.

Gallic Acid Based Black Tea Extract as a Stabilizing Agent in ZnO Particles Green Synthesis

“…It was reported that it consists of about four thousand bioactive compounds like polyphenols, phenols, phenolic acids, alkaloids, amino acids, carbohydrates, proteins, chlorophyll, and volatile organic compounds. The composition is not constant and depends on various factors, with the most important being the origin and age of the plant, and the method of preparation [ 47 , 48 , 49 ]. For these reasons, the exact composition always has to be confirmed.…”

“…These were associated with different functional groups: –OH (~3400 cm −1 ), –CH (~2920 cm −1 ), COOH (1697 cm −1 ), COO − (1697, 1403 cm −1 ), –CH 2 and CH 3 (1448, 1372 cm −1 ), C–O–C (1231, 1030 cm −1 ), –C–O (1145 cm −1 ), aromatic ring (823, 758, 708 cm −1 ), and –OH in phenols (612 cm −1 ) ( Figure S2 ). These attributions were made thanks to the literature data [ 47 , 48 , 49 ], however, due to the occurrence of similar functional groups in the mentioned compounds, it is very difficult to distinguish and name them only on the basis of these results.…”

Periodontal Ligament Fibroblast Cell Viability Following Treatment with Different Concentrations of Green Tea, Aloe Vera and a Mixture of their Extracts

“…Cells were cultured at a density of 5×10 3 in 96-well plates and incubated for 24 hours at 37 0 C before being exposed to the test extracts for 24 hours. MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay was performed as described previously [ 6 , 12 ]. In brief, the culture medium was removed and 10μL MTT solution was added to each well and incubated for 4 hours.…”

“…Past studies have shown that green tea has significant anti-inflammatory, antioxidant and anti-cancer properties [ 9 , 10 ]. The natural com-pounds found in green tea extract exceeds 400 phytochemicals, mainly poly-phenols, which are proven to be active against P. nigrescens , P. intermedia , and P. gingivalis [ 11 , 12 ] . Moreover, EGCG (epigallocatechin-3-gallate), a component of the extract, is known to inhibit bone resorption in periodontal diseases by blocking the expression of matrix metalloproteinase-9 in osteoblasts and pre-venting osteoclast formation [ 13 ].…”

Tea Polyphenols and Their Preventive Measures against Cancer: Current Trends and Directions

“…Fermentation in tea is defined as the oxidation of catechins in the presence of polyphenol oxidase enzymes with the end products being theaflavin, thearubigins, theasinensins, and theabrownins [ 7 ]. Although the fermentation products in black tea demonstrate several biological activities, the antioxidant activity is higher in green tea than that of black tea [ 8 ]. Green tea contains several beneficial compounds.…”