• 한국자원식물학회지
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• 제28권6호
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• pp.734-742
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• 2015

The purpose of this research was to find the most appropriate process for making yacon leaf tea. We applied both green tea and black tea brewing and fermenting methods for producing yacon leaf tea. This research included consumer test and descriptive analysis of professional trained panel on yacon tea tastes and flavors. Both consumer test and descriptive evaluation preferred yacon tea produced by black tea brewing and fermenting methods because it tasted less bitter and had a sweet, delicate taste. According to orthogonal transformation resulting from varimax rotation, first principal component was positively affected by black tea brewing and fermenting methods, while it was negatively affected by green tea brewing and fermenting methods. As a result, the study concluded black tea brewing and fermenting methods were appropriate for producing yacon leaf tea.

• 한국식품조리과학회지
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• 제26권5호
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• pp.567-574
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• 2010

Pork patties were formulated with either steam-dried green tea power or freeze-dried raw tea leaf powder, and the quality characteristics of these products were monitored. Proximate analysis of tea powder contained 17.80~19.85%, 4.70~5.73%, and 5.60~5.77% (as is) crude protein, crude fat, and crude ash, respectively. There were no significance differences in pH among the samples. Chromaticity tended to decrease brightness ($L^*$) and redness ($a^*$), and there were significant differences in yellowness ($b^*$) as the added amount of tea power was increased. For texture, hardness increased as more green tea powder was added. Thiobarbituric acid reactive substances (TBARS) and volatile basic nitrogen (VBN) values increased after storage for 12 days, whereas samples formulated with green tea powder showed lower TBARS and VBN values compared to control groups. Sensory panelists showed preference for samples with green tea powder added compared to the control group.

• 한국가구학회지
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• 제21권4호
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• pp.284-292
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• 2010

This research was carried out to examine the properties of fancy cherry veneer overlaid on the PF resin bonded Meranti plywood floor, which 2.5% green tea leaf powder was applied in the UV varnishes and the adhesives for scavenging the volatile organic compounds. The results were as follows: 1. The various properties of the treated samples, such as density, moisture content, thickness swelling, bending strength(MOR), adhesion shear strength, surface abrasion, curling, cyclic delamination test with boiling water, boiling property, cold-resistance and heat resistance, acid resistance and alkali resistance, and anti-contamination property showed no significant difference between the properties of the control samples. 2.5% green tea leaf powder treated floor gave a little better results than the control for surface scratch test. 2. In case of QUV and weathering test, no difference between the treated sample and control was found. 3. The floor was discolored by adding 10% green tea leaf powder to UV coating, and the floor was also discolored to light green during by the soaking test. The color of floor was not changed up to 5% addition level.

• Journal of Ginseng Research
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• 제16권1호
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• pp.1-6
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• 1992

Chemical composition was determined to evaluate the quality of Panel ginseng-leaf tea over green teas. Ginseng-leaf tea was shown to contain higher contents of soluble matter, ascorbic acid and lower contents of tannins, as compared to tea leaves. The profiles of ginsenoside and sugar of ginseng-leaf tea were noticeably different from those of ginseng roots and the sample maintained high levels of these components under the manufacturing process. Total unsaturated fatty acids and free amino acids were estimated to be decreased in ginseng-leaf tea as compared to those of ginseng leaves. The compositions of amino acids and minerals in ginseng-leaf tea were similar to those of tea leaves and glutamic acid, aspartic acid, leucine, calcium, potassium, sodium, and copper were found to be major components.

• 생물환경조절학회지
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• 제15권1호
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• pp.107-113
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• 2006

These studies were carried out to investigate the quality of green tea processed by different pan-firing hand rolling and to select the best conditions during the procedure of green tea processing the results were as follows. At harvestion tea plant leaf, tea plants had 4 leaves. each leaf size was 7.5 cm'$\square$2.6 cm, and weight of 100 buds 46.6 g. The increase of pan-fired time decreased in the moisture content and yield of green tea. After processing green tea, 5 times pan-fired one had much more contents of total nitrogen (T-N:5.31%), caffeine (2.00%) and total amino acid (T.A.A. : 3,046 mg%) and less content of tannin (13.41%) than the other treatments. but 3 times pan-fired one had the highest contents of vitamin C (204.3 mg%) and chlorophyll (365.0 mg%) among three kinds pan-firing method. Sixteen kinds of free amino acid including theanine as a good taste component of pan-fired green tea were isolated and measured by HPLC. Free amino acid (FAA) contents were in the range of $2,683{\sim}2,925$ mg% and among various pan-firing methods, 5 tims pan-fired one had the highest content of F.A.A. Among these free amino acids, theanine occupied as much as $56.4{\sim}61.3%$ of F.A.A. Lightness, yellowness and redness of 5 times pan-fired green tea were middle value among three different treatments. Besides, it gained the highest score of sensory evaluation among them. These above results suggested that 5 times pan-fired green tea was considered to be the best level as pan-firing times of green tea processing.

• 한국식품과학회지
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• 제31권2호
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• pp.273-279
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• 1999

국내외에서 재배, 유통되고 있는 다류소재 식물류 40종에 대하여 총 페놀성 물질과 비타민 C 함량은 비색법으로, ${\alpha}-tocopherol$과 ${\beta}-carotene$ 함량은 HPLC에 의해, 셀레늄 함량은 원자흡광법을 이용하여 분석하였다. 시료 100 g당(건량) 들어있는 총 페놀성 물질 함량은 녹차잎, 홍차잎, 우롱차잎, 인스탄트커피 등이 약 7g으로 가장 높았고 셀레늄 함량은 산수유와 칡이 약 $4{\mu}g$으로 가장 높았다. ${\beta}-carotene$ 함량은 두충$(8587{\mu}g)$, 감잎$(6222{\mu}g)$, 녹차잎$(3652{\mu}g)$ 등이 매우 높았다. ${\alpha}-tocopherol$ 함량은 감잎(33 mg), 두충(26 mg), 녹차잎(16 mg), 홍차잎(13 mg) 순으로 높았으며, 비타민 C 함량은 녹차잎(199 mg)과 홍차잎(117 mg)이 가장 높았다.

• 한국식품저장유통학회지
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• 제21권4호
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• pp.549-559
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• 2014

뽕잎, 녹차 및 뽕잎과 녹차혼합물이 sterptozotocin 유발 당뇨 쥐의 혈당 조절효과에 대해 살펴보았다. 실험군은 정상군(N), 당뇨 대조군(STZ), 5% 뽕잎 분말 첨가 당뇨군(STZ-M), 5% 녹차 분말 첨가 당뇨군(STZ-G) 및 2.5% 뽕잎과 2.5% 녹차혼합분말 첨가 당뇨군(STZ-MG)으로 5군으로 나누어 4주간 실시하였다. 체중증가량은 뽕잎, 녹차 및 뽕잎과 녹차혼합물 첨가 당뇨군(STZ-M, STG-G, STZ-MG)들이 당뇨 대조군(STZ)에 비하여 유의적 차이는 없었으나 다소 증가하였다. 뇨 중 포도당 함량은 뽕잎, 녹차 및 뽕잎과 녹차혼합물 첨가 당뇨군(STG-G, STZ-MG)들이 당뇨 대조군(STZ)에 비하여 감소효과를 보였다. 4주간 혈당의 변화는 뽕잎, 녹차 및 뽕잎과 녹차혼합물(STZ-M, STG-G, STZ-MG)의 급여로 혈당 수준이 감소하는 경향이었고, 뽕잎과 녹차혼합물 첨가 당뇨군(STZ-MG)이 혈당 강하효과가 가장 높았다. 시험 종료 후 혈청 포도당 함량은 뽕잎, 녹차 및 뽕잎과 녹차혼합물 첨가(STZ-M, STG-G, STZ-MG)로 당뇨 대조군(STZ)에 비하여 모두 유의적으로 낮게 나타나 정상군(N)과 비슷한 경향을 보였다. 혈청 인슐린 함량은 녹차 및 뽕잎과 녹차혼합물 첨가(STG-G, STZ-MG)로 당뇨 대조군(STZ)에 비하여 유의적으로 증가하였고, 혈청 fructosamine 함량은 유의적으로 감소하였다. 이상의 결과 뽕잎, 녹차 및 뽕잎과 녹차혼합물의 급여는 STZ로 유발된 당뇨 쥐의 혈당 강하효과를 확인하여, 당뇨성 질환의 예방 및 개선에 효과가 있을 것으로 사료된다.

• KSBB Journal
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• 제16권2호
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• pp.163-169
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• 2001

This study was undertaken to evaluate the effects of green and taste teas on the in-vitro antimicrobial activity and vacuolating toxin titer of Helicobacter pylori. Crude aqueous extracts prepared by adding 2 g of tea leaf or powder to 100 ml of boiling distilled water, and sterilized by passing through a 0.22 $mutextrm{m}$ membrane filter. Green tea, coffee, and ginger tea showed bactericidal activity on H. pylori within 3 hours. Black tea and ssangwha tea also showed bactericidal activity on H. pylori in 24 hours. Arrowroot tea show no bactericidal effect on H. pylori after 48 hours. Two fold diluted green tea and coffee decreased(1/10,000cfu) the growth of H. pylori in 24 hours, but the two fold diluted black tea, ssangwha tea, and ginger tea showed suppression effect upon of(1/10cfu) H. pylori in 24 hours. The two-fold and 10-fold diluted green tea, coffee and two-fold diluted black tea abrogated the vacuolating toxin titer of H. pylori, but the two-fold and 10-fold diluted ginger, ssangwha, ginseng, and arrowroot tea only reduced the vacuolating toxin titer of H.pylori from 1/2 to 1/8. These result suggest that green tea and coffee have effective antibacterial or bactericidal effects on H.pylori, and that they also have a neutralization effect upon the vacuolating toxin of H.pylori.

• 동아시아식생활학회지
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• 제21권3호
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• pp.367-374
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• 2011

The purpose of this study was to determine the optimum condition for producing tea leaf Jeung-pyun that does not contain added parched tea leafs (0, 0.5, 1, 1.5, and 2%) while producing Jeung-pyun that has a variety of functional ingredients and to investigate the possibility of making practical application of tea leafs. Moisture contents were 56 ~66% and there were no significant differences among the samples. The pH of Jeung-pyun samples was 5.65~5.74. The L-value decreased as the amount of added tea leaf increased, and the a-value was low in the group made with added tea leafs. The b-value was high in the 1% added group and had a tendency to increase vs the control group as amount of added tea leaf increased. In the groups with added tea leaf the volume was evaluated as being higher in the order of 1>1.5>2%. The specific volume of the group with added tea leaf was evaluated as being higher in the order of 1>1.5>2%. Sensory characteristics of the group with added tea leaf were evaluated as being high. For characteristics of cell uniformity, rice wine flavor, and sweetness, the control group was evaluated as being high, and for characteristics of color, moistness, and softness the 1% added group was evaluated as high. Astringency was evaluated as being high in the 2% added group. Texture profile analysis was conducted after samples were maintained in an incubator at $20^{\circ}C$ for 0, 1, 3, 5, and 7 days. Characteristics for hardness, gumminess, chewiness tended to increase with longer periods of storage. Characteristics for cohesiveness, springiness tended to decrease as the storage period increased. As determined by this study, addition of 1% tea leaf was the most favorable method for making use of tea leafs the production of Jeung-pyun and a potentiality for the use of tea leafs in food was discorvered.

• Food Science and Biotechnology
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• 제17권2호
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• pp.349-356
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• 2008

The green tea market is rapidly growing and identifying the driving factors of consumers' liking for the green tea is important in the tea industries. The objectives of this study were to investigate the effects of manufacturing conditions of the green tea on its sensory characteristics, to elucidate its relationship with the consumer liking. A descriptive analysis and consumer acceptability test were conducted for various green tea samples. The samples differed with regard to the source of the tea, the amino acid content, and the processing methods including the roasting temperature. Partial least square regressions (PLS-R) were performed to establish the relationship between the descriptive data and the consumer acceptability data. The PLS-R results showed that the majority of the consumers liked a green tea which has a stronger 'sweet taste' and roasting-related flavors such as 'roasted barley' and 'burnt leaf'. Such sensory characteristics were produced when a sample made of tea leaves mixed with the tea stem was roasted at a high temperature ($250^{\circ}C$) in this study.