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

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.

2021 ◽  
Vol 68 (1) ◽  
pp. 126-136
Author(s):  
U. Chasanah ◽  
N. Mahmintari ◽  
F. Hidayah ◽  
F.A. El Maghfiroh ◽  
D. Rahmasari ◽  
...  

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.


2011 ◽  
Vol 194-196 ◽  
pp. 734-741
Author(s):  
Li Na Yu ◽  
Dong Feng Wang ◽  
Qing Li Yang ◽  
Hai Yan Li ◽  
Bing Jie Liu ◽  
...  

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.


2017 ◽  
Vol 6 (1) ◽  
pp. 32-38 ◽  
Author(s):  
Wara Dyah Pita Rengga ◽  
Arie Yufitasari ◽  
Wismoyo Adi

The synthesis of silver nanoparticles with micro size is highly required in antibacterial fields. The biorefinery material is highly potential as a bioreductor which is applied in the synthesis of nanoparticles. The bioreductor is made from green tea leaves extraction using aquadest to extract its active substance, the catechin which is derived from polyphenol. The polyphenol can reduce the synthesis of silver nanoparticles naturally. The result of FTIR analysis from green tea leaves extract containing polyphenol shown in the uptake functional groups is -OH group located in 3425 cm-1, C=O group located in 1635 cm-1, C=C group located in 1527, and 1442 cm-1 , and C-O group located in 1234 cm-1. The precursors of AgNO3 was used as the main synthetic material. The synthetic condition was resulted from the reaction between the extraction of green tea extract and AgNO3 as the precursors in the variation of synthetizing time. The heating process during synthesizing is done in 50 ?C along with stirring to foster the creation of silver nanoparticles. The analysis result of XRD shows that silver nanoparticles has the diffraction peaks in the angle of 2 theta that are 44.08, 64.40, and 77.51. The types of silver nanoparticles is Ag0 nanoparticles with face-centered cubic crystal structure. Based on TEM analysis, the size and particle size distribution can be determined using image J. The distribution shows that the longer synthesizing time, the bigger nanoparticles produced. With synthesizing times at 24 hours, 6 hours, 3 hours, and 2 hours produce average particle size of 26.4 nm; 9.2 nm; 8.4 nm; and 7.4 nm respectively.


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

Antioxidants ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 362 ◽  
Author(s):  
Xiao-Yu Xu ◽  
Jin-Ming Meng ◽  
Qian-Qian Mao ◽  
Ao Shang ◽  
Bang-Yan Li ◽  
...  

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.


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

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