Optimization of Subcritical Water Extraction of Flavanols from Green Tea Leaves

2014 ◽  
Vol 62 (28) ◽  
pp. 6828-6833 ◽  
Author(s):  
Min-Jung Ko ◽  
Chan-Ick Cheigh ◽  
Myong-Soo Chung
Keyword(s):  
Green Tea ◽  
Subcritical Water ◽  
Water Extraction ◽  
Tea Leaves ◽  
Subcritical Water Extraction ◽  
Green Tea Leaves

scholarly journals Improving the Extraction of Catechins of Green Tea (Camellia sinensis) by Subcritical Water Extraction (SWE) Combined with Pulsed Electric Field (PEF) or Intense Pulsed Light (IPL) Pretreatment

Foods ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3092
Author(s):  
Hee-Jeong Hwang ◽  
Yu-Gyeong Kim ◽  
Myong-Soo Chung
Keyword(s):  
Electric Field ◽  
Green Tea ◽  
Camellia Sinensis ◽  
Subcritical Water ◽  
Intense Pulsed Light ◽  
Water Extraction ◽  
Tea Leaves ◽  
Subcritical Water Extraction ◽  
Tea Catechins ◽  
Green Tea Leaves

The aim of this study was to find the optimum condition of pulsed electric field (PEF) and intense pulsed light (IPL) for the enhancement of subcritical water extraction (SWE), which is an eco-friendly extraction method, for extracting tea catechins from green tea leaves (Camellia sinensis). The leaves were treated with PEF under conditions of electric field strength (1, 2 and 3 kV/cm) during 60 s. Moreover, IPL was applied at various voltages (800, 1000, and 1200 V) for 60 s. The SWE was performed for 5 min at varying temperatures (110, 130, 150, 170, and 190 °C). The maximum yield of total catechin was 44.35 ± 2.00 mg/g dry green tea leaves at PEF treatment conditions of 2 kV/cm during 60 s, as well as the SWE temperature of 130 °C. In the case of IPL treatment, the largest amount of total catechin was 48.06 ± 5.03 mg/g dry green tea leaves at 800 V during 60 s when the extraction temperature was 130 °C. The total catechin content was increased by 15.43% for PEF and 25.09% for IPL compared to the value of untreated leaves. This study verified that PEF and IPL had a positive effect on the enhancement of tea catechins extraction from green tea leaves using SWE.

scholarly journals Subcritical Water Extraction of Epigallocatechin Gallate from Camellia sinensis and Optimization Study Using Response Surface Methodology

Processes ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1028
Author(s):  
Nguyen Tuan Hiep ◽  
Hoang Thanh Duong ◽  
Dang Tuan Anh ◽  
Nguyen Hoai Nguyen ◽  
Do Quang Thai ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Green Tea ◽  
Camellia Sinensis ◽  
Subcritical Water ◽  
Epigallocatechin Gallate ◽  
Water Extraction ◽  
Fast Method ◽  
Subcritical Water Extraction ◽  
Extraction Processes

Background: Camellia sinensis is a plant whose leaves and buds are used to produce tea. With many medicinal activities already found, green tea has been consumed widely in the world. Methods: The subcritical water extraction (SWE) of epigallocatechin gallate (EGCG) from green tea leaves and the effect of the different extraction conditions are investigated by response surface methodology (RSM). Furthermore, the model of the extraction processes is reviewed for application at the industrial scale. Results: Based on the RSM data, the maximum yield of extraction is determined via optimizing different parameters of the extraction processes. Optimal conditions are as follows: extraction time of 6 min, extraction temperature at 120 °C, and a sample/solvent ratio of 1:40 g/mL. Under such conditions, the best yield of EGCG is 4.665%. Moreover, the model of the extraction processes, which can be utilized for industry scale purpose, indicates a good correlation with the experimental data. Conclusions: Overall, SWE is competent and environmental-friendly, and it is also a highly selective and fast method. SWE is a promising method to take the place of organic solvents used in the extraction of weak polar and even non-polar natural compounds. Further studies on the scale-up of the extraction processes are ongoing.

Effects of Soil Selenium Supplementation Level on Selenium Contents of Green Tea Leaves and Milk Vetch

2007 ◽  
Vol 12 (1) ◽  
pp. 35-39 ◽  
Author(s):  
Dae-Jin Kim ◽  
Dae-Soo Chung ◽  
Sung-Chul C. Bai ◽  
Hyeong-Soo Kim ◽  
Yu-Bang Lee
Keyword(s):  
Green Tea ◽  
Selenium Supplementation ◽  
Tea Leaves ◽  
Green Tea Leaves

The potential role of tea in periodontal therapy: An updated review

2020 ◽  
Vol 17 ◽  
Author(s):  
Ali Forouzanfar ◽  
Hamideh Sadat Mohammadipour ◽  
Fatemeh Forouzanfar
Keyword(s):  
Green Tea ◽  
Potential Role ◽  
Wide Spectrum ◽  
Periodontal Diseases ◽  
Herbal Remedies ◽  
World Population ◽  
Tea Leaves ◽  
The World ◽  
Green Tea Leaves

: Periodontal diseases are highly prevalent and can affect high percentage of the world population. Oxidative stress and inflammation plays an important role in the pathogenesis of periodontal diseases. Nowadays, more attention has been focused on the herbal remedies in the field of drug discovery. Green tea is an important source of polyphenol antioxidants, it has long been used as a beverage worldwide. The most interesting polyphenol components of green tea leaves that are related with health benefits are the catechins. Taken together this review suggested that green tea with its wide spectrum of activities could be a healthy alternative for controlling the damaging reactions seen in periodontal diseases.

scholarly journals Green synthesis of reduce graphene oxide by green tea leaves

2021 ◽  
Vol 1795 (1) ◽  
pp. 012070
Author(s):  
Hamsa A. Abdulmageed ◽  
Abdulhadi. K. Judran ◽  
Farah T. M. Noori
Keyword(s):  
Graphene Oxide ◽  
Green Synthesis ◽  
Green Tea ◽  
Reduce Graphene Oxide ◽  
Tea Leaves ◽  
Green Tea Leaves

scholarly journals Development of antibacterial and UV protective cotton fabrics using plant food waste and alien invasive plant extracts as reducing agents for the in-situ synthesis of silver nanoparticles

Cellulose ◽  
2021 ◽  
Author(s):  
Nina Čuk ◽  
Martin Šala ◽  
Marija Gorjanc
Keyword(s):  
Silver Nanoparticles ◽  
Green Tea ◽  
Food Waste ◽  
Cotton Fabrics ◽  
Reducing Agent ◽  
Plant Food ◽  
Japanese Knotweed ◽  
Tea Leaves ◽  
Green Tea Leaves

Abstract The development of cellulose-based textiles that are functionalised with silver nanoparticles (AgNP), synthesised according to a green approach, and offer protection against ultraviolet (UV) radiation and pathogenic bacteria is very important today. In the present work we demonstrate the environmentally friendly approach to obtain such textile material by AgNP synthesis directly (in-situ) on cotton fabrics, using water extracts of plant food waste (green tea leaves, avocado seed and pomegranate peel) and alien invasive plants (Japanese knotweed rhizome, goldenrod flowers and staghorn sumac fruit) as reducing agents. The extracts were analysed for their total content of phenols and flavonoids and their antioxidant activity. The synthesised AgNP on cotton were round, of different size and amount depending on the reducing agent used. The highest amount of AgNP was found for samples where Japanese knotweed rhizome extract was used as reducing agent and the lowest where extracts of goldenrod flowers and green tea leaves were used. Regardless of the reducing agent used to form AgNP, all cotton samples showed excellent protection against E. coli and S. aureus bacteria and against UV radiation with UV protection factor values above 50. The best results for UV protection even after the twelve repetitive washing cycles were found for the sample functionalized with AgNP synthesised with an extract of the Japanese knotweed rhizome. Due to the presence of AgNP on cotton, the air permeability and thermal conductivity decreased. AgNP had no effect on the change in breaking strength or elongation of fabrics. Graphic abstract

Epigallocatechin-3-gallate attenuates acute pancreatitis induced lung injury by targeting mitochondrial reactive oxygen species triggered NLRP3 inflammasome activation

2021 ◽  
Author(s):  
Zhu-Lin Luo ◽  
Hongyu Sun ◽  
Xiao-Bo Wu ◽  
Long Cheng ◽  
Jian-Dong Ren
Keyword(s):  
Reactive Oxygen Species ◽  
Acute Pancreatitis ◽  
Green Tea ◽  
Inflammasome Activation ◽  
Oxygen Species ◽  
Mitochondrial Reactive Oxygen Species ◽  
Tea Leaves ◽  
Nlrp3 Inflammasome Activation ◽  
Health Promoting ◽  
Green Tea Leaves

Green tea has been considered as a health-promoting beverage and is widely consumed worldwide. Epigallocatechin-3-gallate (EGCG), the most abundant polyphenol derived from green tea leaves with potent antioxidative and chemopreventive...

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