scholarly journals SEASONAL VARIATIONS IN ANTIOXIDANT CAPACITIES AND PHENOLIC CONTENTS OF TEA LEAF EXTRACTS

2020 ◽  
pp. 108-112
Author(s):  
TEMSURENLA JAMIR ◽  
AJUNGLA T
Keyword(s):  
Seasonal Variations ◽  
Health Benefit ◽  
Dpph Assay ◽  
Tea Leaves ◽  
Leaf Extracts ◽  
Total Polyphenol ◽  
Phenolic Contents ◽  
Antioxidant Capacities ◽  
Reducing Ability ◽  
Tea Leaf

Objectives: The objective of the study was to estimate the seasonal variations in the antioxidant capacities, total polyphenol content (TPC), total flavonoid content (TFC), and tannin content (TC) of tea leaf extracts from two different plantation sites. Methods: Samples were collected from two tea gardens in Tuli and Ungma situated at N 26°39’19.3 E 094°39’22.7 and N 26°17’30.6 E 094°28’29.2, respectively, under the Mokokchung district of Nagaland, India. TPC, TFC, and TC from sample extracts were determined using Folin–Ciocalteu reagent, aluminum chloride colorimetric, and Folin–Ciocalteu assay. Apart from these, antioxidant capacities were analyzed using ferric reducing ability of plasma (FRAP) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. Results: The concentrations of total polyphenol, flavonoid, and tannin varied from 552.029±8.079 to 305.647±1.744 mg gallic acid equivalent/g, 238.770±0.508–148.457±1.653 mg catechin equivalent/g, and 26.453±0.485–20.173±0.173 mg tannic acid equivalent/g, respectively. FRAP and DPPH assay displayed value ranging from 2.564±0.023 to 1.074±0.023 mmol Fe(II) equivalent/g and 3.612±0.053–2.076±0.028 mmol Trolox equivalent/g. Significant seasonal variations in concentrations of these compounds were observed and a positive correlation between antioxidant capacities and phenolics of tea leaf extracts was established. Conclusion: Tea (Camellia sinensis (L.) O. Kuntze) has been regarded as a plant of immense medicinal and therapeutic value since time immemorial. The tea leaf extracts analyzed in this study gave high TPC, TFC, and TC, as well as high antioxidant activity in terms of DPPH and FRAP value. Studying such properties in tea leaves contributes more to our understandings of health benefit potentials in tea leaves and the quality of tea leaves on the basis of seasons and sites where they are planted.

scholarly journals Antioxidant Activity of Aqueous Extracts of Different Caffeine Products

2011 ◽  
Vol 39 (2) ◽  
pp. 117 ◽  
Author(s):  
Abd El-Moneim M.R. AFIFY ◽  
Emad A. SHALABY ◽  
Hossam Saad EL-BELTAGI
Keyword(s):  
Antioxidant Activity ◽  
Reducing Power ◽  
Hot Water ◽  
Total Phenolic ◽  
Aqueous Extracts ◽  
Power Method ◽  
Tea Leaves ◽  
Total Polyphenol ◽  
Water Extracts ◽  
Phenolic Contents

The antioxidant activity of water extracts (cold and hot) of six caffeine products were carried out. The extracts were screened for total polyphenol contents and antioxidant activity using DPPH, ABTS methods and reducing power method at 50 and 100 μg/ml after 15 min and 30 min using DPPH, ABTS BHA and Caffeine as standard compounds. The results indicated that, the hot water extracts for different caffeine products showed higher antioxidant activity than those of cold extracts and this activity was time and concentration dependent. In addition, the activity was higher against ABTS radical more than DPPH and reducing power methods. Also, there is a positive correlation between the antioxidant and reducing compounds presented in water extracts of different caffeine products. The results of HPLC showed that fresh tea leaves are rich in flavanol monomers known as catechins. The most abundant catechin derivatives in green tea are EGC, EGCG and GC. On the other hand EGCG and GC are major catechin derivative in different caffeine product except El-Fakher tea and Cacao. Generally, these beverages had high antioxidant capacities and total phenolic contents, and could be important dietary sources of antioxidant phenolic for prevention of diseases caused by oxidative stress.

On-site estimation of total polyphenol in fresh tea leaf using near-infrared spectroscopy

NIR news ◽  
2018 ◽  
Vol 29 (1) ◽  
pp. 9-14 ◽  
Author(s):  
Ajanto K Hazarika ◽  
Somdeb Chanda ◽  
Santanu Sabhapondit ◽  
Sandip Sanyal ◽  
Pradip Tamuly ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Heating System ◽  
Inspection System ◽  
Tea Leaves ◽  
Total Polyphenol ◽  
Set Up ◽  
Tea Leaf

The quality of tea liquor primarily depends on the quality of inbound fresh leaves to a tea factory. We report here the development of an industrial set-up using diffuse reflectance near-infrared spectroscopy for quick and on-spot estimation of total polyphenol content, which is one of the major quality indicators of tea. In the inspection system, freshly plucked tea leaves are dried with a heating system designed in such a way that the moisture content is reduced to around 3–4%. The dried leaves are then ground and sieved through a 250 µm mesh. Samples thus produced are placed automatically before the near-infrared beam and assessment of total polyphenol is done instantaneously.

Search for Substances That Inhibit Histamine Production Using Used Tea Leaves

2020 ◽  
Vol 83 (10) ◽  
pp. 1789-1795
Author(s):  
NOBUYUKI TANAHASHI ◽  
MAKOTO AZAMA ◽  
MAI OTSUKA ◽  
FUMIYA OGINO ◽  
RYUHEI MAEDA ◽  
...  
Keyword(s):  
Green Tea ◽  
Detection Method ◽  
Histidine Decarboxylase ◽  
Tea Leaves ◽  
High Concentration ◽  
Leaf Extracts ◽  
Simple Method ◽  
Food Loss ◽  
Histamine Production ◽  
Tea Leaf

ABSTRACT As food waste has become a major problem in recent years, measures against food loss have become an urgent issue. When manufacturing or making green tea beverages, large quantities of tea leaves are subsequently disposed of, which results in potential food loss. Moreover, because many of the tea components remain in the used tea leaves, these continue to have value, as these leaves exhibit antibacterial action. Furthermore, histamine is produced from histidine via histidine decarboxylase that is produced by microorganisms, with histamine accumulation potentially causing histamine food poisoning. Although we have been trying to develop a simple method for detecting histamine, there has yet to be a quick detection method established. We examined whether a method using a low concentration of bromocresol indicator in the culture medium was capable of rapidly detecting histamine. Our results demonstrated that when using lower indicator concentrations, there was a faster detection of histamine production, within 4 h. Using this method, we also investigated whether used tea leaf components, which have antibacterial effects, could suppress histamine production. In this study, used leaves from green, oolong, and black teas were analyzed according to different extraction processes. Compared with green tea, oolong and black teas were able to suppress histamine production using lower concentrations, 25 and 12.5% extracts, respectively. In contrast, the inhibitory effect on histamine production by used green tea leaves required a high concentration of 50% used tea leaf extracts. Furthermore, our results suggested that used tea leaves suppress histamine production and that the inhibitory effects vary according to different extracts. Based on these findings, we propose that (i) a more rapid detection method for histamine should be established and (ii) used tea leaf extracts may have applications in the storage and processing of foods associated with an undesirable production of histamine. HIGHLIGHTS

scholarly journals Further investigation of the biosynthesis of caffeine in tea plants (Camellia sinensis L.). Methylation of transfer ribonucleic acid by tea leaf extracts

1976 ◽  
Vol 160 (2) ◽  
pp. 181-184 ◽  
Author(s):  
T Suzuki ◽  
E Takahashi
Keyword(s):  
Nucleic Acids ◽  
Ammonium Acetate ◽  
Tea Leaves ◽  
Leaf Extracts ◽  
Thiol Compounds ◽  
Caffeine Biosynthesis ◽  
Trna Methyltransferase ◽  
Tea Plants ◽  
Tea Leaf

1. The tRNA methyltransferase activity in vitro of leaves, cotyledons and roots of 85-day-old tea seedlings was studied. 2. The activity of extracts prepared from tea leaves with Polycar AT (insoluble polyvinylpyrrolidine) had optimum pH7.7 and was greatly influenced by thiol compounds, but only slightly by metal ions and ammonium acetate. 3. The activities of extracts, expressed per mg of protein, were as follows: roots greater than leaves greater than cotyledons. The only methylated base isolated after incubation with these preparations was 1-methyladenine. 4. The results did not support the view of involvement of methylation of nucleic acids in caffeine biosynthesis in tea plants. In contrast, it is suggested that theophylline is synthesized from the specific methylated precursor in nucleic acids, namely 1-methyladenylic acid, via 1-methylxanthine.

GROWTH AND DEVELOPMENT OF PRAIRIE GRAIN WIREWORM CTENICERA DESTRUCTOR BROWN (COLEOPTERA:ELATERIDAE), ON SYNTHETIC DIETS

1966 ◽  
Vol 44 (6) ◽  
pp. 995-1001 ◽  
Author(s):  
G. R. F. Davis
Keyword(s):  
Growth And Development ◽  
Water Extract ◽  
Ethanol Extract ◽  
Hot Water ◽  
Tea Leaves ◽  
Leaf Extracts ◽  
Hot Water Extract ◽  
Growth Promoting ◽  
Tea Leaf ◽  
Ctenicera Destructor

Larvae of Ctenicera destructor were fed nine synthetic diets for 6 months at 68 ± 2 °F and 75% relative humidity. Seven of the nine diets were based on a diet developed for larvae of Heliothis sp. It was modified by adding putrescine or spermidine, or both; hot-water or 70% ethanol extract of tea leaves; residue from hot-water extraction of tea leaves; or hot-water extract of germinating rye seed. Two chemically defined diets based on a previously reported amino acid analysis of this wireworm were also formulated: one contained hot-water extract of germinating rye seed.More larvae survived on a diet supplemented with putrescine and spermidine, on one supplemented with hot-water or with ethanol extract of tea leaves, and on the unsupplemented chemically defined diet than on the other diets. They more than doubled their weight on a diet supplemented with putrescine and spermidine. Growth factors for C. destructor present in tea-leaf extracts and residue probably differ from those for Adoxophyes orana. Inhibitory and growth-promoting factors for C. destructor are apparently present in hot-water extract of germinating rye seed. Putrescine or spermidine, or both, or some related metabolic product, may be necessary for growth and development of C. destructor. Frequency of molting was not always indicative of dietary efficiency.

scholarly journals Comparison of Phenolic Contents and Scavenging Activities of Miang Extracts Derived from Filamentous and Non-Filamentous Fungi-Based Fermentation Processes

Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1144
Author(s):  
Aliyu Dantani Abdullahi ◽  
Pratthana Kodchasee ◽  
Kridsada Unban ◽  
Thanawat Pattananandecha ◽  
Chalermpong Saenjum ◽  
...  
Keyword(s):  
Filamentous Fungi ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Protective Effects ◽  
Tea Leaves ◽  
Antioxidant Power ◽  
Phenolic Contents ◽  
Ic50 Values ◽  
Ferric Reducing Antioxidant Power ◽  
The Impact

The study investigated the impact of the fermentation process on the phenolic contents and antioxidant and anti-inflammatory activities in extracts of Miang, an ethnic fermented tea product of northern Thailand. The acetone (80%) extraction of Miang samples fermented by a non-filamentous fungi-based process (NFP) and filamentous fungi-based process (FFP) had elevated levels of total polyphenols, total tannins, and condensed tannins compared to young and mature tea leaves. The antioxidant studies also showed better the half-maximal inhibitory concentration (IC50) values for fermented leaves in both 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity assays as well as improved ferric reducing antioxidant power (FRAP) compared to young and mature tea leaves. Extracts of NFP and FFP samples at concentrations of 50 and 100 ppm showed better protective effects against hydrogen peroxide (H2O2)-induced intracellular reactive oxygen species (ROS) production in HT-29 colorectal cells without exerting cytotoxicity. Additionally, lipopolysaccharide (LPS)-induced production of nitric oxide (a proinflammatory mediator as well as a reactive nitrogen species) was also inhibited by these fermented Miang extracts with an IC50 values of 17.15 μg/mL (NFP), 20.17 μg/mL (FFP), 33.96 μg/mL (young tea leaves), and 31.33 μg/mL (mature tea leaves). Therefore, both NFP-Miang and FFP-Miang showed the potential to be targeted as natural bioactive functional ingredients with preventive properties against free radical and inflammatory-mediated diseases.

scholarly journals Use of a Highly Antioxidant Diet in the Regulation of Adipose Tissue Secretion in Patients after the BIB Procedure

Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1108
Author(s):  
Edyta Balejko ◽  
Jerzy Balejko
Keyword(s):  
Adipose Tissue ◽  
Immune Modulation ◽  
Energy Homeostasis ◽  
Secretory Activity ◽  
Diet Therapy ◽  
Total Polyphenol ◽  
Reducing Ability ◽  
Bariatric Patients ◽  
Antioxidant Diet

Obesity is a global problem. The secretory activity of adipose tissue causes inflammation and disturbs metabolic parameters. Low-invasive bariatric procedures are an alternative to surgical treatment, especially in individuals who do not qualify for surgery or in whom conservative treatment does not bring the expected results. The diets designed for bariatric patients contained an increased proportion of bioflavonoids. The dietary components were carefully selected to provide anti-inflammatory effects. The experimental diets showed an antioxidant capacity (TEAC) of 433–969 µM TE/100 g or 100 mL, reducing ability (FRAP) of 13–58 µM TE/100 g or 100 mL, and total polyphenol content of 80–250 mg catechins/100 g or 100 mL. Lower levels of adipocytokines were obtained in the blood of patients following the diet. The results of the present study showed the participation of some adipocytokines in the regulation of energy homeostasis, lipid metabolism, glucose level, blood pressure and inflammation. Diet therapy should yield positive results in the long term, with the possibility of using immune modulation in personalized therapy for metabolic syndrome.

Biogenic synthesis of Au and Ag nanoparticles using aqueous solutions of Black Tea leaf extracts

2009 ◽  
Vol 71 (1) ◽  
pp. 113-118 ◽  
Author(s):  
Naznin Ara Begum ◽  
Samiran Mondal ◽  
Saswati Basu ◽  
Rajibul A. Laskar ◽  
Debabrata Mandal
Keyword(s):  
Aqueous Solutions ◽  
Ag Nanoparticles ◽  
Black Tea ◽  
Leaf Extracts ◽  
Biogenic Synthesis ◽  
Tea Leaf

scholarly journals Phytotoxic Activity of Parthenium Against Wheat and Canola Differ With Plant Parts and Bioassays Techniques

2016 ◽  
Vol 34 (1) ◽  
pp. 11-24 ◽  
Author(s):  
A. KHALIQ ◽  
F ASLAM ◽  
A MATLOOB ◽  
A JAVAID ◽  
A TANVEER ◽  
...  
Keyword(s):  
Seedling Growth ◽  
Filter Paper ◽  
Leaf Extracts ◽  
Invasive Weed ◽  
Test Species ◽  
Chlorophyll Contents ◽  
Phenolic Contents ◽  
Plant Parts ◽  
Phytotoxic Activity ◽  
Whole Plant

Phytotoxic effects of invasive weed Parthenium hysterophorus were studied by using whole plant, leaf and root aqueous extracts at 0, 2.5, 5.0, 7.5 and 10% (w/v) concentrations against germination and early seedling growth of wheat and canola. Studies were carried out both in Petri plates with filter paper as substratum placed in controlled conditions and soil-filled plastic pots placed in open environments. Pronounced variation was noted for phytotoxic activity of different plant parts of parthenium, aqueous extract concentrations, test species, and bioassay techniques. Aqueous parthenium extracts either inhibited or delayed the germination and suppressed seedling growth of test species over control. For both test species, all the germination attributes were suppressed to a greater extent in Petri plates than in plastic pots. Leaf extracts were more suppressive to germination of test species than whole plant and root extracts. Increasing extract concentration beyond 2.5% caused significant reduction in seedling dry biomass of both test species. Aqueous parthenium extract diminished chlorophyll contents of wheat and canola by 32-63% and 29 69%, respectively. Nevertheless, an increase of 9-172% and 22-60% in phenolic contents of wheat and canola was recorded. Canola appeared to be more susceptible than wheat at all extract concentrations. Present study concluded that bioassays conducted under controlled condition using filter paper as substratum may be misleading due to over estimation of allelopathic response and variation in potential of receiver and donor species. Furthermore, it implies that threshold concentrations of allelochemicals for test species in Petri plates are rarely reached under field conditions.

scholarly journals Phytochemical Screening and in vitro Antioxidant Properties of Methanol and Aqueous Leaf Extracts of Geophila obvallata

2018 ◽  
pp. 1-11
Author(s):  
Iserhienrhien Lucky Osafanme ◽  
Okolie Paulinus Ngozi
Keyword(s):  
Aqueous Extract ◽  
Methanol Extract ◽  
Radical Scavenging Activity ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Scientific Basis ◽  
Phytochemical Analysis ◽  
Leaf Extracts ◽  
Reducing Ability

Aim: This study investigated the phytochemical constituents and in vitro antioxidant properties of methanol and aqueous leaf extracts of Geophila obvallata using standard methods. Materials and Methods: The in vitro antioxidant assays carried out were 1, 1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical scavenging ability, Nitric oxide (NO•) radical scavenging activity assay, 2, 2'-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS•+) radical cation scavenging assay, ferric reducing properties and hydroxyl radical scavenging assays. Results: Phytochemical analysis revealed the presence of alkaloids, flavonoids, phenolic compounds, steroids, saponins, terpernoids and cardiac glycosides in both extracts. Relative to the aqueous extract, the methanol extract contained a higher amount of the secondary metabolites. However, both extracts exhibited appreciable and dose-dependent capacities for quenching DPPH, ABTS•+ and NO• free radicals, and potent ferric reducing ability to levels comparable to those of ascorbic acid. The crude methanol extract showed significantly increased (P<0.05) antioxidant activity than the aqueous extract. Conclusion: It was concluded that the extract possesses strong antioxidant properties due to its content of phytochemicals, and provides scientific basis for its ethno medicinal applications.

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