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

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.

Processes ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1028
Author(s):  
Nguyen Tuan Hiep ◽  
Hoang Thanh Duong ◽  
Dang Tuan Anh ◽  
Nguyen Hoai Nguyen ◽  
Do Quang Thai ◽  
...  

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.


2018 ◽  
Vol 23 (3) ◽  
pp. 124
Author(s):  
Fransiska Lisa Anindya Putri ◽  
Akhmad Kharis Nugroho ◽  
Erna Prawita Setyowati

Green tea (Camellia sinensis L.) is known to have ability to protect skin against free radicals. This is supported by polyphenol compound catechin. This research aims to determine the optimum Hydrophilic-Lipophilic Balance (HLB) value of Tween 60 and Span 80 compositions on the optimum cream formula of ethanol extract of green tea leaves. Tea leaves are extracted by macerating using 70% ethanol. Catechin in extract is known from Thin Layer Chromatography (TLC) test with silica gel 60 F254 as stationary phase and ethyl acetate:aquadest:formic acid (18:1:1 v/v) as mobile phase. Antioxidant activity is determined by 2,2-Diphenyl-1-picryhydrazyl (DPPH) method and value of Inhibition Concentration 50% (IC50) is then calculated. Formula optimization using Design Expert® version 7.1.5 (DX 7) software, Simplex Lattice Design (SLD) method with two components Tween 60 and Span 80. Cream is characterized according to physical properties organoleptic, homogeneity, viscosity, pH, spreadability, adhesiveness, and cream type. The optimum formula obtained is then tested for physical stability for 4 weeks at room temperature (28±2°C) and data are statistically analyzed using one-way ANOVA. The extract contains catechin proved with Retention factor (Rf) value 0.8 and has antioxidant activity with IC50 value 56.35 ppm. 6.4% Tween 60 and 3.6% Span 80 result an optimum HLB value 11.1. It has viscosity 2897.50±35.94 mPa.s, spreadability 18.44±0.06 cm2, adhesiveness 0.85±0.05 seconds, and pH 4.530±0.002. Statistical test shows that the cream is significantly altered at pH, but does not significantly change in viscosity, spreadability, and adhesiveness after being stored for 4 weeks.


2011 ◽  
Vol 6 (3) ◽  
pp. 1934578X1100600
Author(s):  
Toshio Hasegawa ◽  
Kensuke Akutsu ◽  
Yasuhiro Kishi ◽  
Kouji Nakamura

Green tea ( Camellia sinensis) leaves are known to contain active ingredients such as catechins and caffeine, and are widely useful materials. Recently, green tea flowers also have been in the spotlight. However, little attention has been paid to the tea seeds. In this work, the constituents of green tea seeds and green tea leaves were compared. Caffeine was found in the seeds, whereas catechins (usually obtained from green tea leaves) were not observed. Next, we investigated the constituents of hexane extracts and methanol extracts of green tea seeds. We found that the hexane extracts contained high amounts of oleic glyceride (79.9%) in addition to linoleic glyceride (20%). We confirmed the structures of these glycerides by NMR spectroscopy and by synthesis from a fatty acid and glycerol. The methanol extract was found to contain naringenin glucosides by mass spectrometry and NMR spectroscopic analysis.


2019 ◽  
Vol 10 (2) ◽  
pp. 119-128
Author(s):  
Desi Nawangsari

Abstract Green tea (Camellia sinensis L.) has the main efficacy as an antioxidant and contains polyphenol compounds in green tea leaves with the main component of polyphenol fraction namely Epigallocatechin-3-gallate (EGCG) which has strong activity to prevent free radicals that cause premature aging. Research has been carried out on the formulation of maskantioxidant preparations containing green tea leaf extract. The study begins with testing the antioxidant activity of ethanol extract of green tea leaves with a free radical reduction method of 1,1-diphenyl-2-picrylhydrazyl using visible spectrophotometry. Testing of antioxidant activity showed that the ethanol extract of green tea leaves gave an IC50 value of 3.17µg / mL. Formulations of gel masks made were F0 (base without active substances), F1 (base + concentration of ethanol extract of green tea leaves for IC50 (0,000317%)), F2 (base + concentration of ethanol extract of green tea leaves for 50xIC50 (0, 0158%)), F3 (base + concentration of ethanol extract of green tea leaves for 100xIC50 (0.0317%)), F4 (base + concentration of ethanol extract of green tea leaves for IC50), F5 (base + concentration of ethanol extract of green tea leaves worth IC50), F6 (base + concentration of ethanol extract of green tea leaves for IC50. Evaluation of gel mask preparations include, organoleptic examination and homogeneity, pH, viscosity, dry time of preparation and testing of antioxidant stability. F2 provides better and higher free radical reduction activity than products on the market. F4, F5, F6 shows an increase in free radical reduction activity.   Keywords: Green tea leaves (Camellia sinensis L.), DPPh, IC50 gel mask.


2019 ◽  
Vol 10 (2) ◽  
pp. 129-134
Author(s):  
Desi Nawangsari

Abstract   Green tea (Camellia sinensis L.) has the main efficacy as an antioxidant and contains polyphenol compounds in green tea leaves with the main component of polyphenol fraction namely Epigallocatechin-3-gallate (EGCG) which has strong activity to prevent free radicals that cause premature aging. Research has been carried out on the formulation of maskantioxidant preparations containing green tea leaf extract. The study begins with testing the antioxidant activity of ethanol extract of green tea leaves with a free radical reduction method of 1,1-diphenyl-2-picrylhydrazyl using visible spectrophotometry. Testing of antioxidant activity showed that the ethanol extract of green tea leaves gave an IC50 value of 3.17µg / mL. Formulations of gel masks made were F0 (base without active substances), F1 (base + concentration of ethanol extract of green tea leaves for IC50 (0,000317%)), F2 (base + concentration of ethanol extract of green tea leaves for 50xIC50 (0, 0158%)), F3 (base + concentration of ethanol extract of green tea leaves for 100xIC50 (0.0317%)), F4 (base + concentration of ethanol extract of green tea leaves for IC50), F5 (base + concentration of ethanol extract of green tea leaves worth IC50), F6 (base + concentration of ethanol extract of green tea leaves for IC50. Evaluation of gel mask preparations include, organoleptic examination and homogeneity, pH, viscosity, dry time of preparation and testing of antioxidant stability. F2 provides better and higher free radical reduction activity than products on the market. F4, F5, F6 shows an increase in free radical reduction activity.   Keywords: Green tea leaves (Camellia sinensis L.), DPPh, IC50 gel mask.


2017 ◽  
Vol 1 (2) ◽  
pp. 1-5
Author(s):  
Naniek Widyaningrum ◽  
Badie'ah Badie'ah ◽  
Sri Lestari

The dregs of green tea leaves have not been used until today, it is still considered as a waste that is not useful. It is known that the dregs of the green tea leaves contain Epigallocatechin-3-gallate (EGCG), which is quite high. EGCG has benefits as an antibacterial. The long-term goal of this research is the application of cosmetic preparation products from the dregs of green tea leaves that have effectiveness, stability and high economic value. The specific target of this research is to get the dose and concentration of the dregs of green tea leaves in a stable and effective way as anti-acne against Staphylococcus epidermidis (S. epidermidis). The search of the dregs of green tea leaves is by techniques of infundation of liquid fractions with ethyl acetate, identification of EGCG compound by using HPLC, antibiotics test against S. epidermidis was conducted by diffusion method. The results showed that the content of EGCG of the dregs of green tea leaves was 21.325% w/w, and the concentration of 1% of the dregs of green tea leaves can inhibit the growth of S. epidermidis well.


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