• 한국토양비료학회지
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• 제6권1호
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• pp.27-28
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• 1973

적고(赤枯) 및 호마엽고리병엽(胡麻葉枯罹病葉)(엽신상반부위(葉身上半部位)) 중(中)의 Peroxidase와 Polyphenol oxidase의 활성(活性)을 검압법(檢壓法)으로 측정(測定)하였다. 건전엽(健全葉)에서는 Polyphenoloxidase의 활성(活性)이 Peroxidase의 활성(活性)보다 약간 낮지만 라병엽에서는 Polyphenoloxidase의 활성(活性)이 56% 증가(增加)하는데 반(反)하여 Peroxidase의 활성(活性)은 35% 감소(減少)하였다. 이러한 사실에서 리병엽중(罹病葉中)의 Polyphenol류(類)의 산화(酸化)에 Polyphenol oxidase가 주역(主役)을 담당하며 Peroxidase 활성(活性)의 감소(減少)로 $H_2O_2$가 유독수준(有毒水準)까지 집적(集積)하여 Polyphenol류(類)의 비산소적(非酸素的) 산화(酸化)가 예상된다.

• 약학회지
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• 제46권4호
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• pp.237-241
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• 2002

Polyphenoloxidase activity (PPO) in the leaves of Erechitites hieracifolia was estimated by Warburg's manometric method. The emzyme was most reactive toward chlorogenic acid followed by caffeic acid. Diethyldithiocarbamate and potassium cyanide were shown powerful inhibition rate to the polyphenoloxidase from the leaves of Erechitites hieracifolia. We confirmed antioxidant activity of the leaves of Erechitites hieracifolia by DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging method. Electrophorectic isoenzyme banding patterns of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) were observed by native PAGE. The correlation of PPO and antioxidant enzymes is not investigated yet. That is need to further study.

• 한국식품과학회지
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• 제34권3호
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• pp.454-458
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• 2002

과실가공품에서의 갈변을 억제하기 위하여 사과농축액에 갈변억제제 즉, PVPP (polyvinylpolypyrrolidone), bentonite, gelatin, celite 545, tannic acid, sodium sulfite를 첨가하여 여과한 후 갈변억제효과를 측정하였다. 색도의 변화는 PVPP를 첨가한 농축액에서 L값(lightness)이 8.16으로 대조구와 다른 농축액에 비해 갈변억제에 효과가 있음을 알 수 있었으며, 탁도(660 nm에서의 흡광도)는 대조구 0.05인데 비해, PVPP, gelatin celite 545, tannic acid, sodium sulfite를 함유한 사과농축액은 각각 0.003, 0.038, 0.038, 0.018, 0.022로 다소 낮은 수치를 보여 부유물 등의 제거효과가 나타났으며 특히 PVPP의 효과가 뚜렷하였다. 또한, PVPP 처리된 사과농축액 중의 PPO(polyphenoloxidase)활성과 폴리페놀화합물(catechol, catechin, chlorogenic acid, epicatechin 등) 함량에서도 현저하게 감소하여 효소적 갈변이 억제되었음을 알 수 있었다. 따라서, PVPP가 사과농축액의 색상, 탁도, PPO활성 및 폴리페놀화합물 함량 등 효소적 갈변특성을 개선시키는 우수한 갈변억제제임을 확인하였다.

• Food Science and Biotechnology
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• 제18권4호
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• pp.878-883
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• 2009

In Brazil canned 'Biuti' peach is a very popular form of this sub-tropical fruit. This production represents an important economic agro-activity in Minas Gerais, Brazil during the summer period, in preparation for the Christmas celebrations. The aim of this work was to characterize the 'Biuti' peach polyphenoloxidase (PPO), since peach products show enzymatic oxidation of the polyphenols by oxidative enzymes, which affects the products during their shelf life. Two different hypothesis for the browning problem in processed peaches were studied: the inadequacy of the blanching treatment and the presence of a latent phenolase in the peaches. The PPO was characterized: pH optimum (5.5) and stability (5.5-6.5); optimum temperature at $20^{\circ}C$ and 80% of the activity retained after 30 min at $15-40^{\circ}C$. The test for the presence of latent PPO in the processed and canned peaches was negative. Ascorbic acid, ${\beta}$-mercaptoethanol, sodium metabisulfite, and cysteine were efficient in inhibiting the PPO.

• Food Science and Biotechnology
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• 제14권1호
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• pp.117-122
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• 2005

Polyphenoloxidase (PPO) was extracted from Solanum tuberosum Jasim by various chromatographic methods and was subsequently purified and characterized. PPO was purified upto 78-fold from the crude extract. SDS-PAGE profile of the enzyme showed a major subunit of PPO with molecular weight of 40 kDa. The optimum pH and temperature for the maximum activity of PPO was 6.5 and $25^{\circ}C$, respectively. The enzyme was found to be quite stable between 10 and $40^{\circ}C$, whereas it was almost inactivated at $70^{\circ}C$ when incubated for 30 min. Substrate specificity study indicated that catechol was the most suitable substrate for PPO isolated from purple-fleshed potato with a $K_m$ value of 21.1 mM. The most effective inhibitor was ascorbic acid, followed by L-cysteine, citric acid, EDTA, and boric acid. Studies on the effect of metal ion on PPO activity showed that magnesium and copper were inhibitory, while iron and zinc ions increased the activity of PPO.

• Applied Biological Chemistry
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• 제38권4호
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• pp.345-352
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• 1995

진공예냉처리에 의한 표고버섯의 변색, PPO활성 및 유리아미노산 함량 변화에 미치는 영향을 조사 하였다. 저장중 예냉처리한 버섯의 경우 예냉처리하지 않은 버섯에 비하여 표면색택의 변화가 억제되어짐을 알 수 있었다. 한편 저장중 Polyphenoloxidase(PPO) 의 활성은 증가하였는데 예냉처리한 버섯의 경우 예냉처리하지 않은 버섯에 비하여 PPO 활성이 낮게 나타났고 갈변이 진행되면서 그 활성이 상대적으로 더 증가한 것으로 나타났다. 그리고 포장방법에 있어서는 PVC 랩포장한 경우가 골판지 포장한 표고버섯에 비하여 변색이 억제됨을 알 수 있었고 아울러 PPO 활성도 더 낮게 나타났다. 표고버섯의 유리아미노산 함량은 수확 직후에는 2,501 mg%였으며 그 중 glutamic acid가 가장 많았고, 저장중 유리아미노산 함량은 계속 감소하는 경향을 나타내었다. 처리구별 차이를 보면 예냉처리한 버섯의 유리아미노산 함량이 예냉처리하지 않은 버섯에 비하여 전반적으로 높게 나타났으며, 저장온도와 포장방법 그리고 기간에 따라서 상당한 변화를 보였다.

• 한국식품과학회지
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• 제37권1호
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• pp.129-133
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• 2005

Minimally processed and refrigerated(MPR) 셀러드의 미생물학적 안전성 및 저장성 증대를 위하여 이산화염소와 citric acid 처리를 이용하여 실험한 결과 총 호기성 세균을 3.75 log cycle, 효모와 곰팡이는 3.47 log cycle, 대장균은 3.41 log cycle, Listeria 속은 3.38 log cycle 감소시켰다. 물로 세척한 경우는 샐러드의 미생물을 효과적으로 제거하지 못한 반면 화학적 처리구는 생육 미생물을 3.3-3.7 log cycle 감소시킴으로써 식품의 미생물학적 안전성을 보장해 주었다. 또한 샐러드 저장 중 효소적 갈변 원인인 polyphenoloxidase의 활성을 감소시켜 대구조에 비해서 49.73%의 감소를 보였다. 따라서 이산화염소와 citric acid를 이용한 화학적 처리는 MPR 샐러드의 위생학적 안전성을 보장해 주고 또한 갈변 효소의 활성을 억제함으로써 저장성을 증대시키고 유통기간 연장에 도움이 된다고 판단된다.

• 대한약학회:학술대회논문집
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• 대한약학회 2001년도 Proceedings of International Convention of the Pharmaceutical Society of Korea
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• pp.203.1-203.1
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• 2001

• The Plant Pathology Journal
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• 제24권2호
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• pp.171-177
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• 2008

In this study, we investigated the induced defense response and protective effects against Stemphylium vesicarium by application of benzothiadiazole ($Bion^{(R)}$) and di-potassium phosphate salt $(K_2HPO_4)$ to onion. Onion leaves were sprayed with $Bion^{(R)}$ and $K_2HPO_4$, then inoculated 2 days later with a virulent strain of S. vesicarium under greenhouse conditions. Disease severity and activities of peroxidase (PO), polyphenoloxidase, phenylalanine ammonia-lyase (PAL) and phenol contents were evaluated in the treated leaf tissues. Reduction in the disease severity was observed in plants treated with $Bion^{(R)}$ and $K_2HPO_4$. Onion plants treated with $Bion^{(R)}$ and $K_2HPO_4$ and inoculated with the pathogen showed significantly higher PAL activity, PO activity, and phenol contents than inoculated water-treated plants 2 days after the treatment. In conclusion, the results of this study provide evidence that application of simple non-toxic chemical solutions as di-potassium phosphate and $Bion^{(R)}$ can control Stemphylium leaf blight of onion.

• Preventive Nutrition and Food Science
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• 제9권2호
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• pp.121-125
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• 2004

Effects of chemical treatment with a citric acid solution or ozonated water on microbiological changes in lettuce and cabbage during storage were studied. Fresh lettuce and cabbage samples were cut into small pieces and treated by soaking in either ozonated water or a citric acid solution. After treatment, populations of total bacteria, yeast and mold, and E. coli were determined. Numbers of microorganisms increased during storage, but ozonated water and citric acid treatments retarded the increase in microbial growth. Among treatments, 1 % citric acid treatment was the most effective in terms of microbiological change and inhibition of polyphenoloxidase (PPO). For lettuce, citric acid treatment decreased the microbial growth overall by 1.5 log CFU/g and inhibited the PPO activity by 80%. These results indicate that chemical-treated lettuce and cabbage retained a better quality than those of the control during storage.