• Title, Summary, Keyword: polyphenoloxidase

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Diversity in Activities of Peroxidase and Polyphenoloxidase in the Akagare or Helminthosporium-infected Rice Leaves (적고(赤枯) 및 호마엽고(胡麻葉枯) 수도엽중(水稻葉中) Peroxidase와 Polyphenoloxidase의 활성(活性))

  • Park, Hoon;Chun, Jae Kun
    • Korean Journal of Soil Science and Fertilizer
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    • v.6 no.1
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    • pp.27-28
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    • 1973
  • The activities of peroxidase and polyphenoloxidase were investigated in the rice leaves(the upper halves) diseased with Akagare or Helminthosporium oryzae. The activity of polyphenoloxidase was slightly lower than that of peroxidase in the healthy leaves but it increased 56% in the diseased leaves while peroxidase decreased 35%. It was expected that polyphenoloxidase is dominant in the oxidation of polyphenols, and hydrogen peroxide may accumulate to harmful level due to the decrease of peroxidase activity resulting in non-enzymatic oxidation of polyphenols in the diseased leaves.

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Properties of Polyphenoloxidase and Antioxidant Enzymes in the Leaves of Erechitites hieracifolia (붉은 서나물 잎 (Erechitites hieracifolia Raf.)에서의 Polyphenoloxidase 활성측정 및 항산화효소 특성분석)

  • 김안근;이상은;김국환;권영이
    • YAKHAK HOEJI
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    • v.46 no.4
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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.

The Effect of Antibrowning Agents on Enzymatic Reaction in Apple Concentrate (사과농축액에 대한 갈변억제제 처리효과)

  • Kim, Hyeon-Wee;Bae, Soo-Kyung
    • Korean Journal of Food Science and Technology
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    • v.34 no.3
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    • pp.454-458
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    • 2002
  • The effect of antibrowning agents such as PVPP (polyvinylpolypyrrolidone), bentonite, gelatin, celite 545, tannic acid and sodium sulfite in apple concentrate was investigated for the control of enzymatic browning by comparing physicochemical properties (pH, color, turbidity), polyphenoloxidase activity and contents of polyphenol compounds. In color value, apple concentrate containing PVPP showed higher L value (lightness) than control and other antibrowning agents. The turbidity (absorbance at 660 nm) of apple concentrate added PVPP, gelatin celite 545, tannic acid and sodim sulfite were 0.003, 0.038, 0.018 and 0.022, respectively. PVPP was regarded to remove suspended solids effectively. Polyphenoloxidase activity and polyphenolics(catechol, catechin, chlorogenic acid, epicatechin) content of apple concentrate used PVPP significantly reduced. Therefore PVPP was proved to be effective for enzymatic antibrowning agent considering to color, turbidity, polyphenoloxidase activity and polyphenol compounds in apple concentrate.

Characterization of 'Biuti' Peach Polyphenoloxidase

  • Belluzzo, Ana Silvia Fidelis;Fleuri, Luciana Francisco;Macedo, Juliana Alves;Macedo, Gabriela Alves
    • Food Science and Biotechnology
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    • v.18 no.4
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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.

Characterization of Polyphenoloxidase extracted from Solanum tuberosum Jasim

  • Jang, Jae-Won;Ma, Yu-Hyun;Shin, Ju-Mi;Song, Kyung-Bin
    • Food Science and Biotechnology
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    • v.14 no.1
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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.

Influence of Vacuum Cooling on Browning, PPO activity and Free Amino Acid of Shiitake Mushroom (진공 예냉처리가 포장 저장중 표고버섯의 품질에 미치는 영향)

  • Kim, Byeong-Sam;Kim, Oui-Woung;Chung, Jin-Woung;Kim, Dong-Chul;Nahmgung, Bae
    • Applied Biological Chemistry
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    • v.38 no.4
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    • pp.345-352
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    • 1995
  • The influence of vacuum cooling and modified atmospheric packaging was investigated about browning degree, polyphenoloxidase(PPO) activity and free amino acid of shiitake mushroom. During storage, surface browning was inhibited by precooling. PPO activities of shiitake mushroom was increased during storage. Especially, PPO activity was rapidly increased as surface browning was proceeded. And PVC-wrapped mushroom was lower than carton box-packed mushroom in the changes of surface browning and PPO activity. Total free amino acid contents of shiitake mushroom was 2,510 mg% at harvest, but free amino acid content of shiitake mushroom decreased consistantly during storage. Precooled mushroom had more free amino acid content than non-precooled and their contents were fluctuated by storage temperature, packaging methods and storage periods.

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Effect of Aqueous Chlorine Dioxide and Citric Acid Treatment on Microbial Safety and Quality Control of Minimally Processed and Refrigerated (MPR) Salad (이산화염소 및 citric acid 처리가 minimally processed and refrigerated (MPR) salad의 미생물학적 안전성 및 품질에 미치는 영향)

  • Youm, Hyoung-Jun;Ko, Jong-Kwan;Kim, Mee-Ree;Cho, Yong-Sik;Chun, Hye-Kyung;Song, Kyung-Bin
    • Korean Journal of Food Science and Technology
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    • v.37 no.1
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    • pp.129-133
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    • 2005
  • Aqueous chlorine dioxide and citric acid treatment was introduced to insure microbial safety of minimally processed and refrigerated (MPR) salad. Salad samples were treated with 50 ppm chlorine dioxide and 1% citric acid. Chemical treatment decreased total aerobic bacteria, yeast and molds, E. coli, and Listeria by 3.75, 3.47, 3.41, and 3.38 log cycles, respectively, and polyphenoloxidase activity of MPR salad by 49.73%. Plain water washing of salads did not effectively decrease microbial growth. These results indicate appropriate chemical treatment provides microbial safety and quality control in MPR salad during marketing.

Enhanced Onion Resistance against Stemphylium Leaf Blight Disease, Caused by Stemphylium vesicarium, by Di-potassium Phosphate and Benzothiadiazole Treatments

  • Kamal, Abo-Elyousr A.M.;Mohamed, Hussein M.A.;Aly, Allam A.D.;Mohamed, Hassan A.H.
    • The Plant Pathology Journal
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    • v.24 no.2
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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.

Effect of Chemical Treatment with Citric Acid or Ozonated Water on Microbial Growth and Polyphenoloxidase Activity in Lettuce and Cabbage

  • Youm, Hyoung-Jun;Jang, Jae-Won;Kim, Kyu-Ri;Kim, Hyo--Jjung;Jeon, Eun-Hee;Park, Eun-Kyoung;Kim, Mee-Ree;Song, Kyung-Bin
    • Preventive Nutrition and Food Science
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    • v.9 no.2
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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.