• Journal of the Society of Cosmetic Scientists of Korea
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• v.47 no.4
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• pp.281-287
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• 2021

In this study, we analyzed the cosmetic applicability of extract from snow tea, native to Lijiang, Yunnan-province, China. After confirming the species as N. grossedentata through DNA analysis of Lijiang snow tea, experiments were conducted using representative tea, green tea, and a representative control group for each efficacy analysis. Both teas were extracted using 70% (v/v) ethanol aqueous solution. The polyphenol content in the Lijiang snow tea extract (gallic acid equivalent, 23.9 ± 3.2 mg/mL) was higher than that in green tea extract (16.4 ± 2.3 mg/mL). In contrast, the antioxidant (Radical scavenging, IC₅₀ 104 ㎍/mL), tyrosinase enzyme inhibitory (whitening agent, IC₅₀ 40.7 ㎍/mL), and Escherichia coli growth inhibitory (preservative) activities (IC₅₀ 2.85 mg/mL) were analyzed based on the solid content in the extract, and it was confirmed that the activities of Lijiang snow tea extract were superior to those of green tea extract (radical scavenging, IC₅₀ 234 ㎍/mL. It also showed similar efficacy to previously used active substances such as antioxidants (vitamin C, IC₅₀ 108 ㎍/mL), whitening agents (vitamin C, IC₅₀ 80㎍/mL), and preservatives (methylparaben, IC₅₀ 4.35 mg/mL). However, green tea was found to be better in collagenase inhibition activity (anti-wrinkle). Through this study, the cosmetic application potential of Lijiang snow tea is high.

• Korean Journal of Pharmacognosy
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• v.49 no.4
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• pp.328-335
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• 2018

'EGCG(epigallocatechin gallate) rich Green Tea extract(EGTE)' was prepared by a convenient chromatographical manner using water and alcohol which was regarded as the most suitable and appropriate process for food manufacturing. The EGCG content in EGTE was estimated above 97%. Analysis of polyphenol components in green tea, i.e., catechin(C), epigallocatechin(EGC), epicatechin(EC), epigallocatechin gallate(EGCG), epicatechin gallate(ECG) and caffeine was performed by HPLC. The optimized HPLC method exhibited a good linearity of calibration curve, accuracy and precision. The long-term stability evaluation of EGTE was carried out with a powdered formulation and solution formulation by estimating the color change and measuring the EGCG content by HPLC analysis for one year. The EGCG content of the powdered EGTE stored in a transparent bottle at room temperature was retained over 97% at the end of the experimental period. The EGCG content of 0.1% water solution of EGTE stored in a transparent bottle at RT were observed to decrease below 30%, whereas that stored at $2^{\circ}C$ retained over 70%, respectively. These results suggested that a powdered formulation could be recommended for the commercialized nutraceutical product of EGTE rather than a solution formulation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.8
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• pp.1025-1029
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• 2008

Fresh green tea leaf extracts were prepared by different enzyme treatment conditions, such as concentration, treating time and treating temperature using complex enzyme, Rapidase TF, and then extracted for 30 min at $80^{\circ}C$ to investigate their physicochemical properties. The results showed that free sugar content in every sample tended to increase, especially glucose content was increased up to 7.25 times compared to the control. Total amino acid was barely affected by the enzyme treatment and caffeine content was increased with reaction temperature. Total polyphenol and total catechin content was increased according to the amount of enzyme added and reaction temperature. Regardless of enzyme treatment conditions, composition of catechins were epigallocatechin, epicatechin, epicatechin gallate and epigallocatechin gallate by descending order of the content. Gallic acid content increased up to 0.04% and $45^{\circ}C$ with no further significant changes thereafter. From the results above, we could conclude that a simple and new method to extract green tea materials directly from fresh green tea leaves with improved extract ratio may be introduced by adding $0.08{\sim}0.1%$ of Rapidase TF to heat treated fresh green tea leaves and keeping temperature at $37{\sim}45^{\circ}C$ for $180{\sim}240\;min$ in order to skip existing complicated procedures.

• The Korean Journal of Food And Nutrition
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• v.33 no.5
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• pp.570-575
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• 2020

In this study, to develop balloon flower (Platycodon grandiflorum) leaves, which are not used as tea, a method of making green tea was referred to, and several physiological activities were analyzed using the balloon flower leaf tea with different times of roasting and rubbing. The highest total polyphenol and tannin contents were 33.02 mg GAE/g and 5.03 mg/g at two times of roasting and one time of rubbing, respectively. In the case of the total flavonoids, the RO3 + RU2, subjected to three times of roasting and two times of rubbing, showed the highest value, whereas there was no significant difference between the control and the other samples. Except for the green tea as a control, the RO2 + RU1 samples reported the highest antioxidant activity whereas it decreased with increasing number of times of roasting and rubbing. The color, lightness, and yellowness tended to decrease slightly as the number of increasing roasting and rubbing among the samples with no significant difference. All of these things together, to develop tea using the balloon flower leaves would be suitable with two times of roasting and one time of rubbing.

• International Journal of Oral Biology
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• v.45 no.4
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• pp.179-189
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• 2020

Green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) is a potent antioxidant with protective effects against neurotoxicity. However, it is currently unclear whether EGCG protects neuronal cells against radiation-induced damage. Therefore, the objective of this study was to investigate the effects of EGCG on ultraviolet (UV)-induced oxidative stress and apoptosis in PC12 cells. The effects of UV irradiation included apoptotic cell death, which was associated with DNA fragmentation, reactive oxygen species (ROS) production, enhanced caspase-3 and caspase-9 activity, and poly (ADP-ribose) polymerase cleavage. UV irradiation also increased the Bax/Bcl-2 ratio and mitochondrial pathway-associated cytochrome c expression. However, pretreatment with EGCG before UV exposure markedly decreased UV-induced DNA fragmentation and ROS production. Furthermore, the UV irradiation-induced increase in Bax/Bcl-2 ratio, cytochrome c upregulation, and caspase-3 and caspase-9 activation were each ameliorated by EGCG pretreatment. Additionally, EGCG suppressed UV-induced phosphorylation of p38 and rescued UV-downregulated phosphorylation of ERK. Taken together, these results suggest that EGCG prevents UV irradiation-induced apoptosis in PC12 cells by scavenging ROS and inhibiting the mitochondrial pathways known to play a crucial role in apoptosis. In addition, EGCG inhibits UV-induced apoptosis via JNK inactivation and ERK activation in PC12 cells. Thus, EGCG represents a potential neuroprotective agent that could be applied to prevent neuronal cell death induced by UV irradiation.

• Korean Journal of Food Science and Technology
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• v.46 no.4
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• pp.410-417
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• 2014

Berries and green tea are underutilized in the food industry despite their great potential as a functional food ingredients. The purpose of this study was to determine the extraction conditions under which total phenolic contents and antioxidant activities of berry and green tea extracts are maximized. Extracts produced using 0-80% ethanol and temperatures ranging from $5-65^{\circ}C$ were evaluated for total phenolic content (TP), as well as for DPPH and ABTS radical-scavenging activities by using response surface methodology. Both ethanol and temperature had significant effects (p<0.05). Ogaja extract produced at $67^{\circ}C$ by using 33% ethanol yielded maximum TP, ABTS, and DPPH values of 23.74 mg GAE/g, 19.77, and 25.04 mg VCE/g, respectively. Optimum conditions for mulberry and raspberry extraction were found to be $65^{\circ}C$ by using 69% and 40% ethanol, respectively. Mulberry and raspberry extracts had TP, DPPH, and ABTS values of 20.74 mg GAE/g, 23.55, and 35.44 mg VCE/g, and 26.08 mg GAE/g, 39.93, and 55.60 mg VCE/g, respectively. Green tea extraction at $57^{\circ}C$ by using 43% ethanol was found to be optimal, yielding TP, ABTS, and DPPH values of 101.15 mg GAE/g, 171.38, and 177.56 mg VCE/g, respectively.

• Food Science and Biotechnology
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• v.15 no.5
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• pp.672-676
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• 2006

The aim of this study is to evaluate the antioxidant, antimicrobial, and antitumor activities of various concentrations of partially purified substance(s) from green tea seed (Camellia sinensis L.). The total polyphenol contents of each fraction (non-adsorption fraction: F-1, fraction eluted with 40% methanol: F-2, and fraction eluted with 100% methanol: F-3) purified by Diaion HP-20 column chromatography were, in the increasing order: F-1 (3.7 mg tannic acid equivalents, TAB/g) < F-3 (23.2 mg TAB/g) < seed extracts (26.2 mg TAB/g) < F-2 (42.7 mg TAB/g). The scavenging activities toward the 1,1-diphenyl-2-picyrylhydrazyl (DPPH) radical were, in decreasing order: F-2 (93.3%) > butylated hydroxytoluene (BHT; 89.8%) > ascorbic acid (89.3%) > leaf extracts (70.3%) > F-3 (15.9%) > seed extracts (15.8%) > F-1 (14.8%) at a 0.1% concentration. In studies on antimicrobial activities, the results indicate that the growth of yeast (Candida albicans KCCM 11282 and Cryptococcus neoformans KCCM 50544) was inhibited more so than that of other fungi (Alternaria alternate KCTC 6005 and Rhizoctonia solani). In addition, it appears that the antitumor activities of the F-1, F-2, and F-3 fractions at a concentration of $50\;{\mu}g/mL$ showed 6, 7, and 23% growth inhibition of the HEC-1B cell line, 14, 11, 82% inhibition of the HEP-2 cell line, and 8, 16, and 81% inhibition of the SK-OV-3 cell line, respectively. Overall these results indicate that the antioxidant activity is greatest in the F-2 fraction, and the antimicrobial and antitumor activities are greatest in the F-3 fraction.

• Korean Journal of Food Science and Technology
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• v.48 no.4
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• pp.354-360
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• 2016

We investigated the quality and antioxidant activities of sponge cake prepared containing 1-5% of green tea powder (GT). The water content in the cake increased with an increase in the amount of GT added. Although the hardness and springiness of the rice sponge cake increased, the adhesiveness decreased with increasing the level of GT. The cohesiveness, chewiness, and resilience of the rice sponge cake with GT were similar to those of the control. Chromaticity determination revealed that lightness, redness, and yellowness of the crust decreased with increasing GT content. Total polyphenol and flavonoid contents increased proportionally with increasing GT level. Antioxidant activity, measured by DPPH and ABTS radical scavenging as well as reducing power activities, was significantly higher in the rice sponge cake with GT than in the control. Sensory evaluation determined that addition of 1-3% GT to the rice sponge cake maintained the color, taste, texture, flavor, and overall acceptance similar to that of the control.

• Food Science and Preservation
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• v.10 no.3
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• pp.354-359
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• 2003

This study was conducted to investigate the fermentation characteristics of kimchi treated with different methods of water extracts of powdered green tea(GT). Four different kimchis, the SB-kimchi(control) which was not treatment of the extracts, SG-kimchi prepared with Chinese cabbage(CC) salted in 1％ GT containing 10％ brine, DG-kimchi prepared with CC dipped in 1％ GT for 30 min after salting, MS-kimchi prepared with the salted CC mixed with 1％ GT containing seasonings. All kimchis was fermented at 10$^{\circ}C$. The pH of treated-kimchis were maintained higher than those of control products during fermentation, but it showed no big difference between each treated groups. Total microbe of SB-kimchi(6.27-9.37 cfu/mL) was higher than those of GT-treated kimchi(5.17-9.20) during fermentation. The ratio of lactic acid bacteria against total microbe was higher than the treated kimchis. Total polyphenol content of kimchi was 52.75 mg％ in DG-kimchi, 47.71 mg％ in MS-kimchi, 44.89 mg％ in SG-kimchi, 30.70 mg％ in SB-kimchi on the 5th days of fermentation. Scores of crispy taste of SG- and DG-kimchi on the 5th days of fermentation was 4.03 and 4.01 points, respectively which was higher than control products. Scores of fishy and hot taste of GT-treated kimchi were lower than those of control products during all fermentation periods.

• Food Science and Preservation
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• v.10 no.3
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• pp.345-359
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• 2003

This study was conducted to investigate the fermentation characteristics of kimchi treated with different methods of water extracts of powdered green tea(GT). Four different kimchis, the SB-kimchi(control) which was not treatment of the extracts, SG-kimchi prepared with Chinese cabbage(CC) salted in 1％ GT containing 10％ brine, DG-kimchi prepared with CC dipped in 1％ GT for 30 min after salting, MS-kimchi prepared with the salted CC mixed with 1％ GT containing seasonings. All kimchis was fermented at 10$^{\circ}C$. The pH of treated-kimchis were maintained higher than those of control products during fermentation, but it showed no big difference between each treated groups. Total microbe of SB-kimchi(6.27-9.37 cfu/mL) was higher than those of GT-treated kimchi(5.17-9.20) during fermentation. The ratio of lactic acid bacteria against total microbe was higher than the treated kimchis. Total polyphenol content of kimchi was 52.75 mg％ in DG-kimchi, 47.71 mg％ in MS-kimchi, 44.89 mg％ in SG-kimchi, 30.70 mg％ in SB-kimchi on the 5th days of fermentation. Scores of crispy taste of SG- and DG-kimchi on the 5th days of fermentation was 4.03 and 4.01 points, respectively which was higher than control products. Scores of fishy and hot taste of GT-treated kimchi were lower than those of control products during all fermentation periods.