• 한국식품과학회지
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• 제30권2호
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• pp.278-282
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• 1998

편의성과 신선함을 동시에 추구하는 최소가공채소류의 저장 유통중에 품질을 저하시키는 요인중의 하나인 갈변을 억제할 수 있는 적절한 갈변방지제를 선발하기 위하여 ascorbic acid, citric acid 및 allyl isothiocynate (AITC)의 농도를 달리하여 깐마늘, 콩나물, 절단 양파 및 절단 풋고추에 처리하여 저장하면서 이들의 효과를 검토한 결과는 다음과 같았다. 즉 깐마늘은 citric acid 1%, 콩나물은 ascorbic acid 1%, 양파는 citric acid 2%, 풋고추는 ascorbic acid 1% 처리시에 색차가 비교적 낮게 나타나 갈변 억제에 효과가 있는 것으로 나타났다. AITC는 마늘에 있어서 저장 10일까지는 갈변 억제의 효과가 있었으나 다른 품목에 있어서는 오히려 갈변을 촉진하는 것으로 나타났다. 깐마늘은 저장 기간이 경과함에 따라서 시료 표면의 갈변 정도와 polyphenol oxidase의 역가가 증가하였으나 절단 풋고추는 갈변 정도가 커짐에 따라 효소의 역가가 오히려 감소하는 것으로 나타났다.

• 한국균학회지
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• 제14권1호
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• pp.43-47
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• 1986

리그닌과 관련된 대표적인 페놀화합물인 ferulic acid, vanillic acid 및 gallic acid와 단백질합성저해항생제인 cycloheximide와 puromycine 중에서 Lentinus edodes JA01 경우는 gallic acid가 Pleurotus ostreatus는 ferulic acid가 각각 가장 효과적인 inducer였다. gallic acid는 2.0mM에서, ferulic acid는 1.0mM에서 induction이 가장 잘 되었다. Inducer의 처리시기는 접종후 L. edodes는 2일후에, 그리고 P. ostreatus는 3일후에 최고의 활성을 나타내었다. 또한 polyphenol oxidase activity는 균주의 생장곡선에 대체적으로 비례하여 증가하였으나, P. ostreatus 경우는 대수기에서 최고의 활성을 나타내고 그 이후 감소하였다.

• Applied Biological Chemistry
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• 제31권4호
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• pp.331-338
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• 1988

칡뿌리로 부터 칡뿌리 acetone분말을 제조하고 polyphenol oxidase를 추출, 정제하여 정제효소의 효소학적 특성을 검토하였다. 조효소는 DEAE-Cellulose, DEAE-Sephadex A-50, Sephadex G-100 column chromatography에 의하여 정제되었으며, 정제효소의 비활성은 94배, 정제수율은 45.4%이었다. 정제효소는 catechol 및 pyrogallol에 대하여 감한 친화성을 나타내었으며, km 값은 catechel을 기질로 하였을 때 16.67mM이었다. 작용 최적 pH는 7.5, 최적온도는 $50^{\circ}C$에서 가장 잘 작용하였고 1mM L-ascorbic acid, sodium bisulfite, EDTA, KCN 및 $Fe^{3+}$ 이온에 의하여 심한 저해를 나타내었으며, $Zn^{2+}$ 이온을 약 1.7배 정도의 활성을 증가시켰다. 조효소액을 전기영동하여 catechol로 활성염색 하였을 때 5개 isoenzyme이 확인되었으며 그 중 분자량 35,000의 것이 가장 강한 활성을 나타내었다.

• 한국식품조리과학회지
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• 제10권4호
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• pp.339-345
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• 1994

Polyphenol oxidase in Yam was partially purified through ammonium sulfate fractionation, DEAE-cellulose column chromatography. The specific activity of purified PPO was 138.22 unit/mg protein. The optimum pH and temperature of purified PPO were respectively 7.0 and 30$^{\circ}C$. The heat treatment at 80$^{\circ}C$ for 6 min, decreased PPO activity to 50%. The enzyme showed high substrate specificity toward catechol. The Km value for catechol was 5 mM. In the Ames test using S. typhimurium TA98 and TA100 catechol-YEBRP, pyrogallol-YEBRP, chlorogenic-YEBRP showed strong antimutagenicity on sodium azide and MECF excepting hydroquinone-YEBRP showed killing effect on both strains.

• Journal of Ginseng Research
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• 제37권1호
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• pp.117-123
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• 2013

Polyphenol oxidase (PPO) was purified from fresh ginseng roots using acetone precipitation, carboxymethyl (CM)-Sepharose chromatography, and phenyl-Sepharose chromatography. Two isoenzymes (PPO 1 and PPO 2) were separated using an ion-exchange column with CM-Sepharose. PPO 1 was purified up to 13.2-fold with a 22.6% yield. PPO 2 bound to CM-Sepharose, eluted with NaCl, and was purified up to 22.5-fold with a 17.4% yield. PPO 2 was further chromatographed on phenyl-Sepharose. The molecular weight of the purified PPO 2 from fresh ginseng was determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and was about 40 kDa. The optimum temperature and pH were $20^{\circ}C$ and 7.0, respectively, using catechol as a substrate. Pyrogallol showed the highest substrate specificity. The effect of a PPO inhibitor showed that its activity increased slightly in the presence of a low concentration of citric acid. High concentrations of acidic compounds and sulfite agents significantly inhibited purified ginseng PPO 2.

• 약학회지
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• 제40권1호
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• pp.65-71
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• 1996

Characterization of Polyphenol oxidase (PPO) in Perillae Folium, particullarly inhibitor studies were investigated. This enzyme was stable at pH 5.0 and the residual activity of PPO at ${\geq}$ ph 5.5 was estimated to be very low. PPO activity was decreased slightly by adding amino acid with catechol as a substrate, particullary PPO activity was inhibited markedly by cystein, histidine, lysine and arginine. In the absorption spectra of the product formed when catechol was oxidized by PPO, with a ${\lambda}_{max}$ at 410nm, the peak shifted toward ${\lambda}_{max}$ 520nm by addition of L-proline. At relatively low concentrations($10^{-3}M$), sulfite and dithiothreithol completely inhibited PPO activity. Inhibition of PPO activity by amino acids and inhibitors increased or decreased depending on the pH used to measure it.

• 약학회지
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• 제45권4호
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• pp.387-396
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• 2001

The effects of ascorbic acid, thiols such as cysteine, n-acetyl-ι-cyteine, glutathione, thiourea, 2-mercaptoethanol and dithiotreithol and organic acids such as magic acid, citric acid, glycolic acid, taurine and kojic acid on polyphenol oxidate (PPO) activity were studied in order to establish if it reacts with oxidized product and/or directly inhibits the enzyme. To investigate the mechanism, the quantification of t-butylcatechol and 4-methylcatechol (phenolic compounds) as substates, their oxidized product and sulphydryl colorless additional compounds were determined by high performance liquid chromatograph (HPLC) method. Chromatographic results indicate that ascorbic acid, organic acids and lower level of cysteine reduced oxidized product of substrates back to their respective positions uf ο-diphenols. On the other hand, other thiols and high level of cysteine reacted with oxidative product of ο-diphenols and then produced sulphydryl colorless compounds. Cysteine apperars to have two types of mechanism of actions in the formation of oxidative products of substrates depending on its concentration; ascorbic acid-type and other thiols-types. The effect of ascorbic acid with thiols on polyphenol oxidase was determined by same method. Chromatographic results indicate that ascorbic acid was more reactive with oxidized product of substrates than thiols.

• 한국식품영양과학회지
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• 제35권7호
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• pp.955-959
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• 2006

양송이버섯을 5, 10, 50 ppm 이산화염소 용액 처리하여 실온과 $4^{\circ}C$ 각 저장기간 중 중량변화, polyphenol oxidase 활성, 미생물에 대한 살균효과를 측정하였다. 중량감모율의 경우 저장기간이 경과할수록, 이산화염소 처리농도가 증가함에 ‘따라 대조구에 비하여 중량감모율이 감소하였다. polyphenol oxidase 활성은 실온의 경우 이산화염소 처리에 의해 저장 2일까지 일시적으로 증가하다 다시 감소하였는데, $4^{\circ}C$의 경우 이산화염소의 농도가 증가할수록 polyphenol oxidase 활성이 감소하는 것을 확인할 수 있었다. 호기성균수는 이산화염소 처리농도에 따른 큰 차이는 없었으나 $4^{\circ}C$의 경우 10일째 대조구는 $3.72{\times}10^8\;CFU/g$, 50 ppm의 경우 $1.66{\times}10^7\;CFU/g$으로 차이를 보였다. 효모 및 곰팡이의 경우, 이상화염소 처리농도가 증가할수록 대조구에 비해 효모 및 곰팡이수가 감소하는 것을 확인할 수 있었다. 따라서 이산화염소 처리는 양송이버섯의 미생물학적 안전성을 증가시켜, 품질을 유지함으로써 shelf life 증대에 도움을 준다고 판단된다.

• 생약학회지
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• 제15권2호
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• pp.78-84
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• 1984

Polyphenol oxidase was purified from acetone powder extract of the root of Ixeris sonchifolia. The enzyme obtained by ammonium sulfate fractionation and sephadex G-200 gelfiltration gave 51-fold purification over the crude extract. The purified enzyme showed activity toward chlorogenic acid, caffeic acid and pyrocatechol. The kinetics of thermal inactivation of the enzyme followed first-order reaction. Potassium cyanide and cysteine were potent inhibitors.

• 생약학회지
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• 제22권2호
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• pp.101-111
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• 1991

Polyphenol oxidase(PPO) was purified from an extract of Puerariae Radix by ammonium sulfate fractionation followed by Sephadex G-150 column chromatography, which resulted in a 56-fold increase in specific activity. The enzyme was optimum of pH 6.5. The optimum temperature of enzymic reaction was about $40^{\circ}$. The enzyme was thermostable with a half-life equal to 32 min at $70^{\circ}$. Km values of the PPO for catechol and pyrogallol from Lineweaver Burk plots were $1.3{\times}10^{-2}M$, $1.16{\times}10^{-2}M$, respectively. The substrate specificity of the Puerariae Radix PPO showed high affinity toward pyrogallol. Reducing reagents such as cysteine, potassium metabisulfite, ascorbic acid, 2-mercaptoethanol completely inhibited the PPO activity at $10^{-2}M$ level. Linewear-Burk analysis of inhibition data revealed that the inhibition by cysteine, 2-mercaptoethanol, 4-nitrocatechol, potassium cyanide was competitive with Ki values of $4.3{\times10^{-2}M,\;0.73{\times}10^{-6}M,\;6.9{\times}10^{-6}M,\;6.4{\times}10^{-7}M$, respectively. The browning reaction by PPO was observed to decrease temporarily with the addition of sodium diethyl dithiocarbamate, a well known copper chelating agent. Among the divalent cations, $Cu^{2+}$ ion was strong activator on PPO and $Mn^{2+},\;Co^{2+}$ ions was effect on PPO activity. $Zn^{2+},\;Mg^{2+}$ ions was inhibitor on PPO.