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.

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.

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

Immobilization of green tea extract on polypropylene films to control the antioxidant activity in food packaging

2013 ◽  
Vol 53 (1) ◽  
pp. 522-528 ◽  
Author(s):  
Carol López de Dicastillo ◽  
María del Mar Castro-López ◽  
José Manuel López-Vilariño ◽  
María Victoria González-Rodríguez
Keyword(s):  
Antioxidant Activity ◽  
Green Tea ◽  
Food Packaging ◽  
Green Tea Extract ◽  
Polypropylene Films ◽  
Tea Extract

Evaluation of Antioxidant Activity of Green Tea Extract and Its Effect on the Biscuits Lipid Fraction Oxidative Stability

2009 ◽  
Vol 74 (8) ◽  
pp. S362-S370 ◽  
Author(s):  
S. Mildner-Szkudlarz ◽  
R. Zawirska-Wojtasiak ◽  
W. Obuchowski ◽  
M. Gośliński
Keyword(s):  
Antioxidant Activity ◽  
Oxidative Stability ◽  
Green Tea ◽  
Lipid Fraction ◽  
Green Tea Extract ◽  
Tea Extract

scholarly journals Study and evaluation antioxidant activity of dietary supplements with green tea extract

2021 ◽  
Vol 14 (2) ◽  
pp. 215-219
Author(s):  
O. Yu. Maslov ◽  
S. V. Kolisnyk ◽  
M. A. Komisarenko ◽  
A. A. Altukhov ◽  
K. V. Dynnyk ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Dietary Supplements ◽  
Green Tea ◽  
Platinum Electrode ◽  
Green Tea Extract ◽  
Natural Sources ◽  
Low Level ◽  
A Value ◽  
Potentiometric Measurements ◽  
Tea Extract

The aim of the work is to determine and evaluate the antioxidant activity of dietary supplements with green tea extract, as well as to introduce conditional terms of the level of AOA. Materials and methods. The object of the study was dietary supplements of different manufactures: “Green Tea Extract” of Natural Sources, USA (DS1), “Extract of green tea” of Elit-Pharm, Ukraine (DS2) and “Green tea” of Pharmakom, Ukraine (DS3). Potentiometric measurements were conducted by pH meter Hanna 2550 (Germany) with a combined platinum electrode EZDO 5010. Epigallocatechin-3-O-gallate ˃98.0 % (Sigma Aldrich), K3[Fe(CN)6], K4[Fe(CN)6], NaHPO4, KH2PO4 were analytical grade. Results. It was established that a value of the antioxidant activity of DS1 was 36.51 mmol/tab, DS2 – 29.78 mmol/tab, and DS3 – 16.67 mmol/tab. DS1 had the highest value of the antioxidant activity, which correlated with the content of catechins (r2 = 0.9314). According to the proposed conditional terms of antioxidant activity dietary supplements, DS1 and DS2 possessed a low level of antioxidant activity, whereas DS3 corresponded to very low level of antioxidant activity. Conclusions. It was found that the studied dietary supplements with green tea extract have antioxidant activity, which correlates with the content of catechins.

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