scholarly journals Bioavailability and antioxidant activity of tea flavanols after consumption of green tea, black tea, or a green tea extract supplement

2004 ◽  
Vol 80 (6) ◽  
pp. 1558-1564 ◽  
Author(s):  
Susanne M Henning ◽  
Yantao Niu ◽  
Nicolas H Lee ◽  
Gail D Thames ◽  
Rosario R Minutti ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Green Tea ◽  
Black Tea ◽  
Green Tea Extract ◽  
Tea Extract

scholarly journals Thin-layer hydration method to prepare a green tea extract niosomal gel and its antioxidant performance

2021 ◽  
Vol 68 (1) ◽  
pp. 126-136
Author(s):  
U. Chasanah ◽  
N. Mahmintari ◽  
F. Hidayah ◽  
F.A. El Maghfiroh ◽  
D. Rahmasari ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Thin Layer ◽  
Green Tea ◽  
Chorioallantoic Membrane ◽  
Entrapment Efficiency ◽  
Physical Characteristics ◽  
Green Tea Extract ◽  
Gelling Agent ◽  
Niosomal Gel ◽  
Tea Extract

Abstract This study aimed to prepare a niosomal gel of green tea (Camellia sinensis) extract containing catechins, mostly epigallocatechin-3-gallate (ECGC), as a potent antioxidant. Niosomes can increase EGCG's stability and penetration into the skin for a better therapeutic effect. Niosomes were prepared by a thin-layer hydration method, were evaluated for their vesicle shape, particle size, polydispersity index, zeta potential and entrapment efficiency, and then incorporated into gels using sodium alginate as a gelling agent. Three niosomal gel formulations were prepared with different concentrations of niosomes green tea extract. Afterwards, organoleptic properties, chemical and physical characteristics, antioxidant activity, and stability and irritability of the niosomal gels were investigated. The different concentrations of green tea extract had a significant effect on the physical characteristics, but not on the chemical ones. Its antioxidant activity was determined using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging method. The 50% extract green tea niosomes gel showed the highest inhibition value (25.13%). The stability was determined by freeze–thaw and real-time methods; they showed a decrease in pH, but still within the pH range of skin. The irritability test used was the Hen's Egg Test-Chorioallantoic Membrane (HET-CAM) method, which showed no irritation for all formulas. In conclusion, 50% green tea extract niosomes gel results showed it to be the best formulation with optimal antioxidant results.

Synthesis and Antioxidant Activity of Resin of Chitosan Cerium Encapsulated Green Tea Extract Microspheres

2011 ◽  
Vol 194-196 ◽  
pp. 734-741
Author(s):  
Li Na Yu ◽  
Dong Feng Wang ◽  
Qing Li Yang ◽  
Hai Yan Li ◽  
Bing Jie Liu ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Free Radical ◽  
Green Tea ◽  
Polyphenolic Compounds ◽  
Green Tea Extract ◽  
Emission Spectrometry ◽  
Narrow Particle Size Distribution ◽  
Human Beings ◽  
Free Radical Damage ◽  
Tea Extract

The purpose of this paper is to investigate a new type of resin of chitosan cerium encapsulated green tea extract microspheres (RCCM-GTE) prepared by the reversed-phase suspension cross-linking polymerization and study the scavenging activity against DPPH free radical. The results showed that RCCM-GTE was a type of deep brown-yellow spherical resin with smooth surface and it presented uniform and narrow particle size distribution as determined by the Laser Particles Sizer. The Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES), Fourier Transform Infrared Spectroscopy (FT-IR) and differential scanning calorimetry (DSC) study demonstrated that there was cerium existing in RCCM-GTE. The polyphenolic compounds existed in RCCM-GTE and the total content of polyphenolic compounds encapsulated in RCCM-GTE was found to be 92.550±1.145 μg/g. It is considered that the good antioxidant activity of RCCM-GTE was the comprehensive results of the action of tea polysaccharide-protein conjugate, polyphenolic compounds, cerium and Schiff base chitosan. Investigation showed that a lot of extracts coming from agriculture and food industry contain reactive components of polyphenolic compounds and polysaccharides. It can be effective in protection of human beings from free radical damage if these extracts are directly or after the extraction and purification added to food as natural food antioxidant or they are prepared micospheres reacted with some biopolymers through coordination as a health food. Then the emerging area of research on encapsulating GTE in chitosan cerium resin must have a broad developing prospect.

scholarly journals Controlling the Antioxidant Activity of Green Tea Extract through Encapsulation in Chitosan-Citrate Nanogel

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
F. Piran ◽  
Z. Khoshkhoo ◽  
S. E. Hosseini ◽  
M. H. Azizi
Keyword(s):  
Antioxidant Activity ◽  
Particle Size ◽  
Zeta Potential ◽  
Green Tea ◽  
Chitosan Nanoparticles ◽  
Green Tea Extract ◽  
X Ray Diffraction ◽  
Bioactive Ingredients ◽  
Ft Ir ◽  
Tea Extract

Applying bioactive ingredients in the formulation of foods instead of artificial preservatives is problematic because bioactive ingredients are unstable and sensitive to environmental conditions. The present study aimed to control the antioxidant activity of green tea extract (GT) through encapsulating in chitosan nanoparticles (CS-NP). The synthesized nanoparticles were analyzed by using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction (XRD). The encapsulation efficiency (EE), particle size, zeta potential, and polydispersity index (PDI) of GT-loaded CS-nanoparticles (CS-NP-GT) were assessed. Based on the results, the particle size and zeta potential related to the ratio of CS to GT of 1 : 0.5 were obtained as 135.43 ± 2.52 nm and 40.40 ± 0.2 mV, respectively. Furthermore, the results of FT-IR and XRD confirmed the validity of encapsulating GT in CS-NP. In addition, the antioxidant activity of GT increased after nanoencapsulation since the IC50 value of CS-NP-GT decreased to 6.13 ± 0.12 μg/ml. Finally, applying these particles for delivering GT polyphenols in foods is regarded as promising.

Effect of different doses of un-fractionated green and black tea extracts on thyroid physiology

2010 ◽  
Vol 30 (8) ◽  
pp. 884-896 ◽  
Author(s):  
Amar K Chandra ◽  
Neela De ◽  
Shyamosree Roy Choudhury
Keyword(s):  
Thyroid Gland ◽  
Green Tea ◽  
Harmful Effect ◽  
Black Tea ◽  
Green Tea Extract ◽  
Male Rats ◽  
Thyroid Peroxidase ◽  
Black Tea Extract ◽  
Green And Black Tea ◽  
Tea Extract

Tea is a rich source of polyphenolic flavonoids including catechins, which are thought to contribute to the health benefits of it. Flavonoids have been reported to have antithyroid and goitrogenic effect. The purpose of this study was to evaluate whether high doses of green and black tea have a harmful effect on thyroid physiology. Un-fractionated green and black tea extracts were administered orally to male rats for 30 days at doses of 1.25 g%, 2.5 g% and 5.0 g%. The results showed that green tea extract at 2.5 g% and 5.0 g% doses and black tea extract only at 5.0 g% dose have the potential to alter the thyroid gland physiology and architecture, that is, enlargement of thyroid gland as well as hypertrophy and/or hyperplasia of the thyroid follicles and inhibition of the activity of thyroid peroxidase and 5′-deiodinase I with elevated thyroidal Na+, K+-ATPase activity along with significant decrease in serum T3 and T4, and a parallel increase in serum thyroid stimulating hormone (TSH). This study concludes that goitrogenic/antithyroidal potential of un-fractionated green tea extract is much more than black tea extract because of the differences in catechin contents in the tea extracts.

Black tea increases hypertonic stress resistance in C. elegans

2018 ◽  
Vol 9 (7) ◽  
pp. 3798-3806 ◽  
Author(s):  
Pei Yuan ◽  
Lian-yun Pan ◽  
Li-gui Xiong ◽  
Jie-wen Tong ◽  
Juan Li ◽  
...  
Keyword(s):  
Green Tea ◽  
Stress Resistance ◽  
Black Tea ◽  
Green Tea Extract ◽  
Hypertonic Stress ◽  
C Elegans ◽  
Black Tea Extract ◽  
Tea Extract

Black tea extract is more effective than green tea extract in protecting C. elegans against hypertonic stress, within the studied concentration range.

Uji Aktivitas Antioksidan Teh Daun Sirsak (Annona Muricata Linn) Berdasarkan Teknik Pengolahan

2019 ◽  
Vol 4 (2) ◽  
pp. 84
Author(s):  
Mega Yulia ◽  
Riki Ranova
Keyword(s):  
Antioxidant Activity ◽  
Green Tea ◽  
Black Tea ◽  
Annona Muricata ◽  
Oolong Tea ◽  
Activity Test ◽  
The People ◽  
Expected Benefits ◽  
Tea Extract ◽  
Processing Techniques

<p><em>Teh merupakan salah satu minuman yang banyak dikonsumsi oleh masyarakat setelah air.   Berbagai macam jenis daun telah diolah menjadi teh oleh masyarakat seperti daun sirsak. Manfaat yang diharapkan dari mengkonsumsi teh daun sirsak adalah sebagai sumber antioksidan yang dapat menangkal berbagai jenis penyakit karena adanya kandungan acetogenin. Untuk menghasilkan teh yang bermutu tinggi, penanganan pucuk pasca panen perlu dilakukan dengan teknik sebaik mungkin. Penelitian ini bertujuan untuk mengetahui aktivitas antioksidan ekstrak teh daun sirsak berdasarkan variasi teknik pengolahan teh. Pengolahan dilakukan dengan 3 (tiga) variasi teknik pengolahan teh yaitu teh hijau, teh hitam dan teh oolong. Uji aktivitas antioksidan dilakukan dengan metoda penangkapan radikal bebas menggunakan DPPH (1,1-Difenil-2-pikrihidrazil).  Hasil penelitian menunjukan bahwa persentase inhibisi teh hijau sebesar 42,776%, teh oolong 39,962%, dan teh hitam 43,902%.  Aktivitas antioksidan tertinggi didapatkan pada pengolahan teh hitam daun sirsak.  Dari hasil penelitian dapat disimpulkan bahwa perbedaan teknik pengolahan teh tidak memberikan pengaruh terhadap aktivitas antioksidan.</em></p><p><em><br /></em></p><p><em><em>Tea is one drink that is widely consumed by people after water. Various types of leaves have been processed into tea by the people such as soursop leaves. The expected benefits of consuming soursop leaf tea is as a source of antioxidants that can ward off various types of diseases due to the presence of acetogenin. To produce high quality tea, handling after harvest needs to be done with the best possible technique. This study aims to determine the antioxidant activity of soursop leaf tea extract based on variations in tea processing techniques. Processing is done with 3 (three) variations of tea processing techniques, there are green tea, black tea and oolong tea. The antioxidant activity test was carried out by the method of capturing free radicals using DPPH (1,1-Diphenyl-2-pikrihidrazil). The results showed that the percentage of inhibition of green tea was 42.777%, oolong tea was 39.962%, and black tea was 43.902%. The highest antioxidant activity was found in the processing of soursop leaf is a black tea. From the results of this study can concluded there are differences in tea processing techniques do not affect the antioxidant activity</em></em></p>

scholarly journals Effects of Tannase and Ultrasound Treatment on the Bioactive Compounds and Antioxidant Activity of Green Tea Extract

Antioxidants ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 362 ◽  
Author(s):  
Xiao-Yu Xu ◽  
Jin-Ming Meng ◽  
Qian-Qian Mao ◽  
Ao Shang ◽  
Bang-Yan Li ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Green Tea ◽  
Bioactive Compounds ◽  
Ph Value ◽  
Enzymatic Reaction ◽  
Green Tea Extract ◽  
Ultrasound Treatment ◽  
Ultrasonic Power ◽  
Ultrasonic Time ◽  
Tea Extract

The present study investigated the effects of tannase and ultrasound treatment on the bioactive compounds and antioxidant activity of green tea extract. The single-factor experiments and the response surface methodology were conducted to study the effects of parameters on antioxidant activity of green tea extract. The highest antioxidant activity was found under the optimal condition with the buffer solution pH value of 4.62, ultrasonic temperature of 44.12 °C, ultrasonic time of 12.17 min, tannase concentration of 1 mg/mL, and ultrasonic power of 360 W. Furthermore, phenolic profiles of the extracts were identified and quantified by high-performance liquid chromatography. Overall, it was found that tannase led to an increase in gallic acid and a decrease in epigallocatechin gallate, and ultrasounds could also enhance the efficiency of enzymatic reaction.

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