• Korean Journal of Medicinal Crop Science
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• v.7 no.2
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• pp.101-106
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• 1999

These studies were carried out to investigate the quality of green tea processed by different 1st-pan-firing time and to select the best conditions of green tea processing. The results were as follows. At harvesting tea plant leaf, tea plants had 4 leaves, each leaf size was $6.4cm\;{\times}\;2.4cm$, and weight of 100 buds was 40.2g. The content of moisture of green tea was decreased with the prolongation of 1st-pan-firing time, and the yield of green tea at 10 min. pan-firing time was the highest value of 20.12%. After processing green tea, 1st 10 min. pan-fired one had much more contents of total nitrogen(TN 5.41%) and total amino acid(T.A.A; 3,282mg/100g) and less content of tannin(13.22%) and caffeine(1.64%) than the other treatments. The content of chlorophyll and vitamin C went down with the extension of 1st pan-firing period. Sixteen kinds of free amino acid including theanine as a good taste component of green tea were isolated and measured by HPLC. T.A.A contents were in the range of $2,447{\sim}3,192mg/100g$ and among various pan-firing methods, 10 min. 1st pan-fired one had the highest content of T.A.A. The taste-determinants such as theanine, aspartic acid, serine, glutamic acid and arginine in green tea liquor, occupied as much as $89.4{\sim}90.0%$ of T.A.A.s. Among these, theanine was more than 50%, Lightness and yellowness of green tea were increased with delay of pan-firing time, while green color appeared to be more distinct at 10 min. 1st pan -firing time than other treatments. Besides, it gained the highest score of sensory evaluation among them. These above results suggested that 10 min. pan-fired green tea was considered to be the best level as pan-firing time of green tea processing.

• 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.

• Proceedings of the Korean Society of Crop Science Conference
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• 2002.05a
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• pp.77-81
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• 2002

The scope of the research is investigation of immune-modulating activities of A. rugosa (Baechohyang) extract was preformed through the screening active constituents using in vitro assays and evaluating anti-inflammatory activity and anti-atherosclerotic activity of the extract and active compound (tilianin) in vivo. In addition, various functional foods using the extract and whole plant was developed. The extract showed strong anti-inflammatory activity in carrageenan-induced acute edema mouse model and anti-atherogenic lesion activity in LDLR (low density lipoprotein receptor) deficient mouse model. These activities were thought to be resulted from modulation activity of several pathways of inflammation process. Among the main constituents of Baechohyang, polyunsaturated fatty acids (PUFA), Phytosterols, oleanolic acid and rosmarinic acid showed anticomplement activity, and PUFA, acacetin and tilianin newly showed potent ICAM-1 expression inhibition activity. The processes of extraction, mixing ratio of additives and storage conditions were established for drinks, granule tea, leaf tea, mixed tea and furigake.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2007.11a
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• pp.366.1-366.1
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• 2007

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.7
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• pp.1079-1084
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• 2004

The present study was conducted to compare antioxidant activity of green teas, fermented teas and other related common teas by examining radical scavenging activity using DPPH (2,2 diphenyl l-picryl hydrazyl). Scavenging activity ($SC_{50}$/) of epigallocatechin gallate (EGCG) for 0.1 mM DPPH radical was 5.5 $\mu$M or 4.2 mg/L by weight, then catechin, 14 $\mu$M or 2.5 mg/L and vitamin C, 22 $\mu$M or 3.9 mg/L, respectively. Kyokuro tea (okro) powder of 24.2 mg/L or green tea powder of 25.2 mg/L was used to reach $SC_{50}$/ for 0.1 mM DPPH. One serving of 2 g green tea provides antioxidant activity equivalent to 109∼147 mg EGCG, 145∼185 mg catechin or 131∼168 mg vitamin C. Teas from the first harvest had the highest radical scavenging activity when compared with later harvest green teas grown in the same region, but there is virtually no difference by the harvest time. A Chinese green tea, Dragon well had the highest antioxidant activity among other green teas tested providing antioxidant capacity equivalent to 168 mg EGCG or 188 mg vitamin C per 2 g serving, but partially fermented Chinese teas had much lower antioxidant activity than any green tea tested. Black tea which is fully fermented showed as strong antioxidant activity as green teas (76.3 mg vs 86.7∼67.6 mg per tea bag). One tea bag of green teas from market provided antioxidant capacity equivalent to 52∼86 mg EGCG, 70∼105 mg catechin or 63-96 mg vitamin C. Teas made of persimmon leaf, pine needle, mulberry leaf had comparatively low anti-oxidant activity equivalent to 2.5∼4.8 mg EGCG or 15∼21 mg vitamin C per teabag. The third brewed green tea still had enough antioxidant activity, while tea from tea bag brewed for 3 min or 5 min did not have any difference in their antioxidant activity. More systemic studies are needed to clarify the relationship between tea catechins and antioxidant capacity focusing on how growing, harvest time, fermentation and other processes can influence on this.

• Korean Journal of Food Science and Technology
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• v.9 no.1
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• pp.10-12
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• 1977

Chemical constituents and amino acid contents of tea leaves which were harvested three times (May, July and August) from the tree at two different locations were studied. The contents of total nitrogen, ascorbic acid and amino acid decreased, while those of fiber and tannin increased in the order of May, July and August crops. No differences were observed in the contents of reducing sugar, caffeine and ash among tea leaves harvested at different times. There were no effects of locations on the contents of chemical constituents of tea leaves.

• Journal of Sericultural and Entomological Science
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• v.53 no.2
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• pp.71-77
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• 2015

Much attention has been focused on the activity of the natural antioxidants present in fruits and vegetables, because potentially these components may reduce the level of oxidative stress. Especially, mulberry leaves containing many natural components are considerable resource for natural antioxidants. The antioxidant capacity of mulberry leaves was investigated with minilum L-100 device and ARAW-KIT (anti-radical ability of water-soluble substance), in comparison to the ascorbic acid. The antioxidant capacity of 16 varieties was 3303.4 nmol at opening stage of five leaves in spring. The highest stage of antioxidant capacity (3708.0 nmol) and yield rate was just before the coloration stage with anthocyanin in fruits, whereas the lowest stage was middle of June (2231.6 nmol) and about two months growing stage after summer pruning (2064.6 nmol). But after summer pruning, the antioxidant capacity of mulberry leaves increased gradually until just before fallen leaves stage. Even if samples were same variety, antioxidant effect of those showed different results according to collected regions. Also, antioxidant effect of mulberry leaves were higher than that of branches. The antioxidant capacity of yield-type mulberry leaves and fruits (Morus alba L., M. bombycis Koidz, and M. Lhou (Ser.) Koidz) collected from In-je, Won-ju and Yang-yang regions, Kang-won province, Korea, was investigated. The results indicated that total antioxidant capacity of yield-type mulberry leaves was 2711.2 nmol. In the antioxidant capacity analysis of Jeollabuk-Do genetic resources, autumn's mulberry leaves showed higher antioxidant capacity than that of spring's it. To investigate the effect of tea on antioxidative capacity, five kinds of tea(coffee mix, green tea added brown rice, mulberry leaf tea, Polygonatum odoratum tea and black tea added lemon) were selected and analyzed. Their's anti-oxidative capacity were 2,531.01 nmol, 1,867.42 nmol, 1,053.72 nmol, 292.71 nmol and 188.91 nmol, respectively. The antioxidative capacity of drinking water soaked with mulberry leaf showed 891.96 nmol.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.6
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• pp.1053-1059
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• 2001

This study was conducted to estimate the content of antioxidant components and investigate the antioxidative activity of mustard leaf kimchi added pumpkin powder (P) and green tea powder (G). Mustard leaf kimchi added different ratios of P and G were prepared and fermented for 30 days at 5$^{\circ}C$ (properly fermented time). The contents of chlorophyll, total phenol, carotenoids and ascorbic acid in mustard leaf kimchi samples were estimated. The 30 day fermented mustard leaf kimchi added 0.3% P and 0.2% G had relatively higher content of antioxidant components than the other kimchi samples. Based on this result, antioxidative activities of mustard leaf kimchi added 0.3% P and 0.2% G and control kimchi were investigated, that is, methanol extracts of the mustard leaf kimchi samples were prepared and investigated the antioxidative activities. The antioxidative activity of mustard leaf kimchi added 0.3% P and 0.2% G was significantly (p<0,05) higher than control kimchi, and that of the 30 day fermented mustard leaf kimchi at 5$^{\circ}C$ was also significantly higher (p<0.05) than the fresh mustard leaf kimchi. Therefore, it is suggested that antioxidative activity of the 30 day fermented mustard leaf kimchi added 0.3% P and 0.2% G at 5$^{\circ}C$ was the best compared to the other kimchi samples.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.44 no.1
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• pp.67-72
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• 2018

Green tea (Camellia sinensis L.) has been widely explored for its medicinal applications. However, most of the studies had targeted the green tea leaf, while other parts remained unexplored. In this study, protective effect of green tea root extract on Normal Human Epidermal Keratinocytes (NHEKs) against the damage induced by an external stimulant (PM2.5) was confirmed. Thirty-year-old green tea root samples were collected from Amorepacific's Dolsongi tea field and green tea root extract was prepared with 70% ethanol. Total crude saponin content in green tea root extract was 54%, which is much higher than that in ginseng extract. Our results suggest that green tea root extract can be used as a natural surfactant in cosmetics. For evaluating its protective effect against the damage induced by PM2.5, IL-36G was used as a biomarker. IL-36G mRNA expression level increased remarkable upon PM2.5 treatment in NHEKs. Moreover, IL-36G was recently reported to be expressed in psoriasis lesions. Results showed significant decrease of IL-36G expression by treatment of green tea root extract. In conclusion, thirty-year-old green tea root extract can be used as a natural surfactant with a high saponin content and may have protective effect against the damage induced by PM2.5.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.2
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• pp.232-239
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• 1996

돌연변이 유발 물질인 mitomycin C(MMC)를 처리하여 배양한 Chinese hamster ovary(CHO) cell에 대한 감잎차 추출액의 항돌연변이 효과를 자매 염색 분체 교환(sister chromatid exchange, SCE) 시험법을 사용하여 측정하여 보았다. 감잎차 추출액 자체는 CHO 세포의 SCE 빈도수를 변화시키지 않았으며, 세포의 분열 주기중 S phase에 S9 mixture 없이 감잎차 추출액이 처리되었을 경우 MMC로 유도된 SCE 빈도수를 감소시키지 않았다. 그러나 S9 mixture 존재하에 $G_{1}$ phase에서 MMC 처리 후 감잎차를 처리하는 후처리 방식으로 감잎차 추출액을 처리하였을 때, 저농도($\leq$40$\mu\textrm{g}$/ml)에서 MMC로 인해 유발된 SCE 빈도수가 낮아지는 것을 볼 수 있었다. 이에 비해 고농도(>40$\mu\textrm{g}$/ml)에서는 SCE 빈도수의 감소 효과가 없었다. 본 연구결과, MMC 처리된 CHO 세포에 대한 감잎차 추출액의 항돌연변이 효과를 볼 수 있었고, 이 효과는 S9 mixture 존재하에서 저농도의 감잎차 추출액이 $G_{1}$ phase에 처리되었을 때 나타났다. 감잎차 추출액의 이러한 항돌연변이의 효과의 기전은 감잎차 추출액의 대사산물이 MMC 처리된 CHO 세포에 대한 DNA-excision repair activity를 촉진시키기 때문인 것으로 생각된다.