• Preventive Nutrition and Food Science
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• 제14권1호
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• pp.49-53
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• 2009

Antioxidative activities of major pentacyclic terpenoids from the semi-fermented tea of Camellia sinensis L. were investigated. The free radical scavenging activities of triterpenoids $1{\sim}3$ were examined with of DPPH and superoxide anion radical scavenging activity. The $IC_{50}$ of compounds 1 and 2 for DPPH radical scavenging activities were 23.1 and $37.2{\mu}g/mL$ respectively, and for superoxide anion radical scavenging activities were 37.2 and $35.2{\mu}g/mL$, respectively. According to this result, compounds 1 or 2 in semi-fermented tea could be the candidates for bioactive material having antioxidant activity.

• 한국식품영양과학회지
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• 제28권1호
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• pp.100-106
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• 1999

Use of chemical preservative for controlling harmful microorganisms in food products has been debated due to public concerns about food quality because of perceived toxic and carcinogenic potential. Thus, use of non toxic natural antimicrobial agents has become essential. This study was investigated to determine the antimicrobial activity of water or ethanol extract of commercially available tea, and of solvent fractionated ethanol extracts obtained from steamed green tea. Both of water and ethanol extracts of green tea(steamed or roasted), oolong tea and black tea exhibited strong antimicrobial activity against gram positive and negative bacteria, but not effective against yeast and mold. Also, antimicrobial activity of ethanol extract of 4 different kinds of tea was stronger than that of water extract. Among 4 different tea, ethanol extract of steamed green tea was further fractionated. One thousand g/disk buthanol extract had the strongest antimicrobial activity against bacteria and mold. The concentration of the antimicrobial activity of buthanol extract in tested microorganisms ranged from 125~1000 g/disk except for Rhizopus javanicus. Antimicrobial activity of buthanol extract of steamed green tea was not destroyed by heating at 100oC for 60 min and at 121oC for 15 min, which is very stable over heat treatment. The inhibitory effect of the buthanol extract on the growth of Listeria monocytogenes and Staphylococcus aureus was investigated. Growth of both strains was started in the presence of 250 and 500 g/ml after 12 and 24 hour respectively, whereas complete inactivation of both strains was occurred in the presence of 1000 g/ml.

• 한국식생활문화학회지
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• 제9권4호
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• pp.411-417
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• 1994

우롱차의 에탄올 추출 특성을 조사하기 위하여 추출농도 및 온도별로 우롱차의 품질에 미치는 유효성분들을 분석, 조사하였다. 우롱차엽의 에탄올 추출물은 추출시 $80{\sim}85^{\circ}C$, 50%이상의 에탄올 농도에서 대체적으로 높은 수율을 나타내었다. 추출물의 유효성분 분석에서 유리당은 sucrose가 $37.2{\sim}55.0\;mg/100\;g$로 가장 함량이 많았으며 반면에 arabinose는 $3.3{\sim}5.6\;mg/100g$로 가장 낮은 함량을 나타내었다. 에탄올 추출물의 유기산 함량은 furmaric acid가 $0.2477{\sim}0.7842\;mg/g$, citric acid가 $0.2047{\sim}0.6204\;mg/g$ malic acid가 $0.1619{\sim}0.4382\;mg/g$로 주요 유기산으로 나타났다. 유리아미노산은 aspartic acid, glutamic acid, serine, histidine 등 15종류가 나타났으며 그 중에서 proline이 $0.693{\sim}1.681\;mg/g$으로 가장 많이 나타났고 tyrosine, glutamic acid, valine, aspartic acid 등도 다른 유리아미노산보다 많은 양을 보였다. 추출조건에 따른 탄닌의 함량은 물과 25% 에탄올농도에서 38.6, $38.5\;{\mu}g/100\;g$을 나타냈고 추출용매의 농도가 높을수록 탄닌의 함량은 낮아져 95% 에탄올 농도에서는 $24.2\;{\mu}g/100\;g$을 나타내었다. 카페인의 함량은 추출용매의 차이에도 뚜렷한 변화를 나타내지 않았고 그 함량은 $12.65{\sim}14.08\;mg/g$이었으며 ascorbic acid의 함량은 물과 25% 에탄올농도에서 $6.95\;{\mu}g/g$과 $6.50\;{\mu}g/g$을 나타냈고 추출용매의 농도가 높아질수록 ascorbic acid의 함량은 낮아져서 95% 에탄올에서는 $2.78\;{\mu}g/g$을 나타내었다. 추출용매의 농도에 따른 관능검사 결과 떫은 맛과 쓴맛이 전체적인 기호도에 가장 높은 상관계를 나타내었으며 에탄올 농도를 25%로 하여 추출한 우롱차의 전체적인 기호도가 가장 높게 나타났다.

• Journal of Biosystems Engineering
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• 제41권2호
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• pp.85-92
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• 2016

Background: The same plant, Camellia sinensis, is used to produce all types of tea, and the differences among the various types arise from the different processing steps that are used. Based on the degree of fermentation, tea can be classified as black, green, white, or oolong tea. Of these, black tea is the most or fully fermented tea. The oxidized polyphenolic compounds such as theaflavins (TF) and thearubigins (TR) formed during fermentation are responsible for the color, taste, flavor, and aroma of black tea. Results: Research indicates that an optimum ratio of TF and TR (1:10) is required to ensure a quality cup of tea. The concentrations of TF and TR as well as desirable quality characteristics increase as fermentation time increases, reaching optimum levels and then degrading if the fermentation time is prolonged. It is also necessary to control the environment for oxidation. There are no established environment conditions that must be maintained during the fermentation of the ruptured tea leaves. However, in most cases, the process is performed at a temperature of $24-29^{\circ}C$ for 2-4 h or 55-110 min for orthodox tea or crush, tear, and curl (CTC) black tea, respectively, under a high relative humidity of 95-98% with an adequate amount of oxygen. Conclusion: The polyphenolic compounds in black tea such as TF and TR as well as un-oxidized catechins are responsible for the health benefits of tea consumption. Tea is rich in natural antioxidant activities and is reported to have great potential for the management of various types of cancers, oral health problems, heart disease and stroke, and diabetes and to have other health benefits such as the ability to detoxify, improve urine and blood flow, stimulate, and improve the immune system.

• Food Science and Biotechnology
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• 제15권1호
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• pp.1-4
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• 2006

The biological qualities of green, black, and oolong teas were monitored by observing their microbial decontamination and insect disinfestation following gamma irradiation (0-10 kGy) and fumigation (MeBr or $PH_3$) during 6-month storage at room temperature. Plodia interpunctella Hubner was found as an important quarantine pest in teas used. In a comparative study, both treatments were found to be effective in disinfecting the stored samples. An irradiation dose of 5 kGy was sufficient to control all microorganisms related to the quality of teas, while fumigation with methyl bromide and phosphine showed no appreciable decontamination effect on the microorganisms. As a result, irradiation was found an effective alternative to fumigants for the improvement of biological tea qualities during storage.

• Journal of Nutrition and Health
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• 제31권8호
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• pp.1355-1364
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• 1998

This study was planned to investigate the effect of 40 plant ethanolic extracts on antioxidant activities in vitro. The total phenolics, $\beta$-carotene, $\alpha$-tocopherol and selenium contents were also determined . Antioxidant activities fo the ethanolic extracts(0.02%, w/w) in the soybean oil were measured both by determining the peroxide value (POV) during 35 days of storage at 4$0^{\circ}C$ in a forced draft air-incubator and by determining changes in conductivity at 11$0^{\circ}C$(Rancimat method.). Soybean oil without any additives was used as a control and that treated with 0.02% BHT was used as a positive control. Based on the POV determination, green tea extract was found to be the most effective in stabilizing soybean oil, then followed by long tea, which both of them showed higher antioxidant activities compared to the BHT treatment. The antioxidant activities of them showed higher antioxidant activities compared to the BHT treatment. the antioxidant activities of coffee, cinnamomi cortex, acanthopanacis cortex, black tea, orange peel , instant coffee, peony and crni fructus extracts were stronger compared to the control .By the Rancimat method, green tea leaf and oolong tea leaf, foxglove, acanthopanacis cortex and peony extracts. Compared to other extracts, green tea leaf, black tea leaf, foxglove, acanthopanacis cortex and peony extracts had stronger antioxidative effects in both the POV and Rancimat methods used in this study. ethanolic extracts which showed the stronger antioxidative effect also has the higher contents of total phenolics, $\beta$-carotene, and/or $\alpha$-tocopherol. The antioxidative effect of ethanolic extracts was found to be due to the combined effect of various antioxidants.

• 농약과학회지
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• 제15권1호
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• pp.28-35
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• 2011

안산 및 수원시에서 유통 중인 다류 19품목(감잎차, 국화차, 녹차, 라벤더차, 로즈마리차, 민들레차, 보이차, 뽕잎차, 수국차, 자스민차, 나미향차(찹쌀차), 메밀차, 쑥차, 연화차, 오룡차, 용정차, 장미차, 철관음차, 화과차)을 대상으로 218종의 농약 잔류실태를 조사하였다. 조사대상 65건 중 19건에서 15종(bifenthrin, bromopropylate, chlorpyrifos, cyhalothrin, cypermethrin, chlorfenapyr, dicofol, endosulfan, fenpropathrin, fludioxonil, fenvalerate, iprobenfos, isoprothiolane, tetradifon, triazophos)의 농약이 검출돼 23.1%의 검출률을 나타냈다. 검출된 농약의 잔류량은 0.01~1.24 mg/kg으로 대부분 잔류허용기준 이하로 나타났으나 보이차(2006 년산) 1건에서 bifenthrin이 기준치(0.3 mg/kg)를 초과한 것으로 나타났다. 검출된 농약 15종에 대한 위해도를 평가한 결과 EDI/ADI 값은 0.0001~0.0844%로 나타나 다류에 존재하는 잔류농약은 안전한 수준인 것으로 평가되었다.

• 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.

• 한국식품영양과학회지
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• 제40권2호
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• pp.177-182
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• 2011

본 연구는 녹차가루가 포함된 유과의 섭취가 실험동물의 체중 및 혈중 지질변화에 미치는 영향에 관하여 평가하였다. 원산지가 다른 총 5종의 녹차(부초차, 옥로차, 용정차, 우롱차, 홍차)를 첨가하여 유과를 제조한 후 사료와 혼합하여 마우스에 섭취시킨 결과 유과 단독 섭취군에 비하여 녹차가 첨가된 유과를 섭취한 실험동물에서 체중 및 혈중 콜레스테롤 수치가 유의적으로 감소하는 경향을 나타내었으며, 간 조직 및 복부지방의 조직의 검경결과 간세포의 염증 억제, 복부 지방세포의 무게 및 크기 감소 등의 효과가 관찰되었다. 따라서 유과의 제조 시 녹차가루의 첨가는 기존 유과가 지닌 단점을 개선시킬 수 있는 효과적인 방법이라 사료된다.

• 한국식품저장유통학회지
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• 제10권3호
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• pp.421-426
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• 2003

도체표면에서 분리한 E. coli O157;H7 CDF1, A. sobria CDF3, S. aureus CDF2의 성장을 억제하기 위한 방안을 검토하였다. E. coli O157:H7 CDF1와 A. sobria CDF3는 NaCl 4% 이상 농도에서 성장이 억제된 반면 lactic acid 0.1%는 성장에 영향을 미치지 않았다. S. aureus CDF2은 NaCl 농도 4%에 의해 성장이 뚜렷하게 억제되지 않았으나 lactic acid 0.1% 첨가에 의해 뚜렷히 억제되었다. E. coli O157:H7 CDF1은 분쇄육에서 4$^{\circ}C$와 1$0^{\circ}C$에서 10일간 저장하는 동안 저장온도별 약 1 log 차이를 나타내었고,1. sobria CDF3의 성장은 저장온도에 따른 차이는 나타나지 않았다. 6$0^{\circ}C$에서 10분 열처리 후 E. coli O157:H7 CDF1, A. sobria CDF3가 거의 사멸하였으나 S. aureu CDF2는 대조구에 비해 1 log cycle 이하의 감소현상을 나타내었다. 감잎, 뽕잎, 녹차, 우롱차의 추출물중 E. coli O157:H7 CDF1, A. sobria CDF3와 S. auren CDF2에 대한 항균활성을 나타낸 우롱차 추출물 0.1%와 0.3% 첨가에 의해 표. coli O157:H7 CDF1는 성장 억제되지 않았으나 0.5% 첨가구의 경우 약 2 log 감소하였다. A. sobria CDF3와 S. aureus CDF2는 추출물 0.1%와 0.3% 첨가에 의해 성장이 억제되었으며 0.5%첨가에 의해 배양 12 시간이후 생균수는 검출되지 않았다. 우롱차 추출물을 분쇄육에 0.3%와 0.5%를 첨가하여 2$0^{\circ}C$에서 24시간 저장한 결과는 E. coli O157:H7 CDF1, A. sobria CDF3와 S. aureus CDF2은 우롱차 추출물을 0.5%첨가한 경우 성장이 억제되는 경향을 나타내었다.