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Dissertations / Theses on the topic 'Polyphenol oxidase'

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Published: 4 June 2021

Last updated: 26 July 2025

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1

Burton, Stephanie Gail. "Biocatalytic and biomimetic studies of polyphenol oxidase." Thesis, Rhodes University, 1994. http://hdl.handle.net/10962/d1004088.

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Mushroom polyphenol oxidase (EC 1.14.18.1) was investigated to determine its potential for application as a biocatalyst in the synthesis of o-quinones, in organic medium. In order to determine the kinetic properties of the biocatalyst, a system was devised which comprised an immobilised polyphenol oxidase extract, functioning in chloroform. The system was hydrated by the addition of buffer. A simple method for the consistent measurement of reaction rates in this heterogenous system was designed and used to obtain detailed enzyme kinetic data relating to optimisation of reaction conditions and

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2

Boshoff, Aileen. "The biotransformation of phenolic pollutants using polyphenol oxidase." Thesis, Rhodes University, 2002. http://hdl.handle.net/10962/d1004035.

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The potential of using mushroom polyphenol oxidase (EC 1.14.18.1) as a biocatalyst for the biotransformation of phenols to produce catechols in an aqueous medium was investigated. Polyphenol oxidase is characterised by two distinct reactions i.e., the ortho-hydroxylation of phenols to catechols (cresolase activity) and the subsequent oxidation of catechols to orthoquinones (catecholase activity). In order to facilitate the development of a process to produce catechols, the accumulation of catechol as a true intermediate product released in the reaction system needed to be investigated, as its

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3

Bao, Haihong. "Biocatalysis of tyrosinase in organic solvent media using phenolic substrate models." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ50716.pdf.

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4

Cho, Byoung-Mi. "Purification and immobilisation of mushroom polyphenol oxidase (E.C. 1.14.18.1.)." Thesis, University of Reading, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.254958.

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5

Barthet, Véronique J. "Polyphenol oxidases from cassava (Manihot esculenta C.) root : extraction, purification and characterization." Thesis, McGill University, 1997. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=34697.

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Polyphenol oxidases are important enzymes because of their role in food spoilage, oxidizing monophenols into o-diphenols and/or diphenols into the corresponding o-quinones. The resulting compounds are unstable and can rapidly form brown colored compounds, called melanins. Polyphenol oxidases, (PPOs) have been purified from several sources, particularly from fruits and vegetables. However, successful purification of PPO to homogeneity from plant sources has always been difficult.<br>The purification procedure of PPOs from cassava tuber consisted of (1) the preparation of cassava acetone powder;

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6

Astarci, Erhan. "Production And Biochemical Characterization Of Polyphenol Oxidase From Thermomyces Lanuginosus." Master's thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/1254861/index.pdf.

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Polyphenol oxidases are enzymes that catalyze the oxidation of certain phenolic substrates to quinones in the presence of molecular oxygen. Polyphenol oxidases are widely used in several applications. In food industry, they are used for enhancement of flavor in coffee, tea and cocoa production, and determination of food quality. In medicine, they have several uses in treatments of Parkinson&rsquo<br>s disease, phenlyketonurea and leukemia. In wastewater treatment, they are used for the removal of phenolic pollutants from wastewaters. In pharmaceutical industry, differentiation of morphine from

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7

Gouzi, Hicham. "Extraction et caractérisation biochimique des polyphénol oxydases de champignons et leur application en biocatalyse supportée." Thesis, Paris 6, 2014. http://www.theses.fr/2014PA066668/document.

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Ce travail concerne l'extraction d'enzymes de la famille des polyphénol oxydases à partir de champignons, leur caractérisation biochimique et leur immobilisation dans des matrices solides. Ces enzymes ont tout d'abord été extraites du champignon de Paris (Agaricus bisporus) puis partiellement purifiées. Une étude de leur activité enzymatique, de leur domaine de stabilité et de leur comportement thermique a été effectuée, ainsi que l'identification d'inhibiteurs. Cette approche a été étendue à la polyphénol oxydase de la truffe de désert (Terfezia leonis Tul.). Ces deux enzymes ont ensuite été

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8

Ekinci, Olcun. "Immobilization Of Glucose Oxidase And Polyphenol Oxidase In Conducting Copolymer Of Pyrrole Functionalized Polystyrene With Pyrrole." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/2/12607373/index.pdf.

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Electrochemical polymerization of pyrrole functionalized polystyrene (PStPy) with pyrrole was carried out in water-sodium dodecyl sulfate solvent-electrolyte couple. Characterization of the resulting copolymer was performed via Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and four probe conductivity measurements. Glucose oxidase and polyphenol oxidase enzymes were immobilized in polypyrrole (PPy) and conducting copolymer of pyrrole functionalized polystyrene with pyrrole (P(PStPy-co-Py). Resulting enzyme electrodes were characterized by kinetic parameters<

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9

Fang, Caodi. "CHARACTERIZATION OF POLYPHENOL OXIDASE AND ANTIOXIDANTS FROM PAWPAW (ASIMINA TRIBOLA) FRUIT." UKnowledge, 2007. http://uknowledge.uky.edu/gradschool_theses/477.

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The latest generation of fighter aircraft utilizes a 270Vdc power system [1]. Such high voltage DC power systems are difficult to protect with conventional circuit breakers because the current does not automatically go to zero twice per cycle during a fault like it does in an AC power system and thus arcing of the contacts is a problem. Solid state power controllers (SSPCs) are the solid state equivalent of a circuit breaker that do not arc and which can respond more rapidly to a fault than a mechanical breaker [2]. Present SSPCs are limited to lower voltages and currents by the available powe

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10

Utami, Tyas. "Some studies on mushroom polyphenol oxidase in liquid and solid solvents." Thesis, University of Reading, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317147.

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11

Tinello, Federica. "Innovative technologies and bioactive compounds for the control of polyphenol oxidase." Doctoral thesis, Università degli studi di Padova, 2016. http://hdl.handle.net/11577/3424449.

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The enzymatic browning and melanogenesis are associated respectively with the most of qualitative and economical losses during post-harvest processing in agro-food industry and human skin disorders in cosmetic field. The main responsible is tyrosinase or polyphenol oxidase (PPO, EC 1.14.18.1), a copper-containing oxidoreductase that catalyses two different enzymatic reactions involving polyphenolic substrates and oxygen and producing dark pigments. Recently, the research of new eco-friendly systems for controlling PPO activity is focused on innovative non-thermal technologies and bioactive c

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12

Boyukbayram, Ayse Elif. "Immobilization Of Invertase, Polyphenol Oxidase And Glucose Oxidase In Conducting Copolymers Of Thiophene-capped Polytetrahydrofuran And Pyrrole." Phd thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12605935/index.pdf.

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ABSTRACT IMMOBILIZATION OF INVERTASE, POLYPHENOL OXIDASE AND GLUCOSE OXIDASE IN CONDUCTING COPOLYMERS OF THIOPHENE-CAPPED POLYTETRAHYDROFURAN AND PYRROLE B&ouml<br>y&uuml<br>kbayram, AySe Elif Ph.D., Department of Chemistry Supervisor: Prof. Dr. Levent Toppare January 2005, 123 pages Immobilization of invertase, polyphenol oxidase (PPO) and glucose oxidase (GOD) enzymes were performed in electrochemically synthesized two types of conducting copolymers. One end and two end thiophene-capped polytetrahydrofuran (TPTHF-1 and TPTHF-2) were copolymerized with pyrrole under conditions of constan

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13

Sutay, Didem. "Isolation, Characterization And Immobilization Of Polyphenol Oxidases From Mulberry (morus Alba) Leaf Tissues." Master's thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/1262955/index.pdf.

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In this study, the aim was to find an economical plant source for polyphenol oxidase (PPO) production as an alternative to mushroom and possible application areas by characterization and immobilization of the PPOs. For this purpose, tissues of various plants of no commercial value were screened for their PPO activities. Mulberry leaf tissues showed the highest PPO activity against 4-methyl catechol which was comparable to that of mushroom. Average Km and Vmax values of free mulberry leaf PPOs were found as 7 mM and 218 U/ml, respectively. Mulberry leaf PPOs were immobilized in a polypyrole mat

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14

Miyawaki, Miyuki. "Control of polyphenol oxidase and pectin methylesterase activities by ultra high pressure." Online access for everyone, 2006. http://www.dissertations.wsu.edu/Dissertations/Spring2006/M%5FMiyawaki%5F033106.pdf.

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15

Falguera, Pascual Víctor. "Polyphenol oxidase: Activity, properties of its products and inactivation by innovative technologies." Doctoral thesis, Universitat de Lleida, 2012. http://hdl.handle.net/10803/107819.

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Polyphenol oxidase (PPO) affects both kinds of matters that are nowadays at the forefront of the quality concept: those aspects related to health and those regarding organoleptic perception of food. In this Thesis, PPO activity has been characterized in different fruits and situations, and mathematical models to describe melanin formation from monophenolic and o diphenolic substrates have been developed. In addition, potential toxicity of these melanins on the pancreatic proteases carboxypeptidase A, carboxypeptidase B and trypsin has been studied. The second part of the Thesis covers PPO inac

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16

Edwards, Wade. "Capillary membrane-immobilised polyphenol oxidase and the bioremediation of industrial phenolic effluent." Thesis, Rhodes University, 1999. http://hdl.handle.net/10962/d1008458.

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Waste-generating industrialisation is intrinsically associated with population and economic proliferation. This places considerable emphasis on South Africa's water shortage due to the integral relationship between population growth rate and infrastructure development. Of the various types of industry-generated effluents, those containing organic pollutants such as phenols are generally difficult to remediate. Much work has been reported in the literature on the use of enzymes for the removal of phenols from these waste-streams but little application of this bioremediation approach has reached

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17

Kelly, Katrina E. "Synthesis, Oxidation, and Distribution of Polyphenols in Strawberry Fruit During Cold Storage." Scholar Commons, 2018. https://scholarcommons.usf.edu/etd/7314.

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Plants inherently produce polyphenols (i.e., antioxidants) as a response to reduce oxidative stress caused by abusive environmental pre- and postharvest conditions. These antioxidants, as well as vitamin C, are present in considerable levels in strawberries; however, excessive oxidative stress brought on by improper postharvest handling conditions can reduce the levels of antioxidants in the fruit and shorten the shelf-life of strawberries. Nevertheless, it may be possible to utilize strawberry’s naturally occurring polyphenols to reduce postharvest stress and extend their shelf life. The poly

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18

Hossain, Abzal. "Immobilization of selected enriched polyphenol oxidases and their biocatalysis in organic solvent media." Thesis, McGill University, 2004. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=85557.

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Polyphenol oxidase (PPO) enzymatic extracts were recovered from apple fruit and potato tubers and enriched by an acetone precipitation. The enriched PPO extracts were immobilized by adsorption onto a wide range of inorganic supports, including chitin, alumina oxide, glass beads, Celite, Dowex and Silica gel using selected media, including water, sodium phosphate buffer and a ternary micellar system. The highest immobilization efficiencies and specific activities were obtained when the PPO extracts were suspended in sodium phosphate buffer and adsorbed onto alumina oxide. Biocatalysis of

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19

Cil, Mahmut. "Immobilization Of Glucose Oxidase And Polyphenol Oxidase In Poly(n-(4-(3-thienyl Methylene)-oxycarbonylphenyl) Maleimide)-co-pyrrole) Matrice." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/2/12607372/index.pdf.

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In this study, glucose oxidase and polyphenol oxidase were immobilized in conducting copolymer poly(N-(4-(3-thienyl methylene)-oxycarbonylphenyl)maleimide)-co-pyrrole(P(MBThi-co-Py)). A copolymer was electrochemically synthesized by using sodium dodecyl sulfate (SDS) as supporting electrolyte and characterized by FTIR, scanning electron microscopy (SEM) and conductivity measurements. Immobilization of glucose oxidase (GOD) and polyphenol oxidase (PPO) enzymes were performed in conducting PPy and P(MBThi-co-Py) matrices by electropolymerization. Kinetic parameters, maximum reaction rate (Vmax)

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20

Şimşek, Şebnem Yemenicioğlu Ahmet. "Production of commercially suitable pectin methylesterase and polyphenol oxidase from agro-industrial wastes/." [s.l.]: [s.n.], 2004. http://library.iyte.edu.tr/tezler/master/gidamuh/T000508.doc.

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21

Taylor, Rosannah. "Time-dependent appearance of polyphenol oxidase: a possible mechanism explaining the bimodal growth response of the wood-decay fungus coriolus versicolor to polyphenol in culture." DigitalCommons@Robert W. Woodruff Library, Atlanta University Center, 1986. http://digitalcommons.auctr.edu/dissertations/1610.

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22

Madani, Wigdan. "Characterization of a polyphenol esterase from Aspergillus niger and its role in the inhibition of tyrosinase." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0035/NQ64612.pdf.

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23

Bannister, Magdalien. "Comparison of free and immobilized polyphenol oxidase enzymes for the biocatalytic conversion of catechins into theaflavins." Diss., University of Pretoria, 2013. http://hdl.handle.net/2263/30922.

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The reusability of active enzyme is important in industrial bio-catalysis applications. This is not readily accomplished with free enzymes. The project investigated a new enzyme immobilization matrix, ReSynTM, and compared it to three widely used matrixes, Eugergit C, Eupergit C 250 L and DEAE Sephadex A-25. Initial comparative immobilization performed with BSA, determined ReSynTM (covalent immobilization) to have an approximate 8 fold higher protein loading efficiency than the other support. The enzymes selected for immobilization were polyphenol oxidase (PPO) (first reported purificati

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24

Ferreira, Elys Raquel Andrade. "Filmes de polipirrol como matrizes para a imobilização da polifenol oxidase e aplicação como biossensores amperométricos na análise de compostos fenólicos." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/88/88131/tde-01122014-112608/.

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Nesta dissertação, a polifenol oxidase (PFO) como extrato bruto de abacate (Persea americana) foi imobilizada em filmes de polipirrol (PPI) sintetizados eletroquimicamente utilizando o glutaraldeído (GA) como um agente de ligação entrecruzada. Os filmes PPI e PPI/PFO-GA foram caracterizados por eletroquímica, principalmente voltametria cíclica, sendo avaliadas a eletroatividade e a reversibilidade eletroquímica. A detecção de compostos fenólicos em soluções padrão foi feita por cronoamperometria, tendo um controle sobre a concentração dos compostos. O processo de transferência de massa foi mon

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25

Scherman, Patricia Ann (neé Goetch). "The microbial production of polyphenol oxidase enzyme systems and their application in the treatment of phenolic wastewaters." Thesis, Rhodes University, 1992. http://hdl.handle.net/10962/d1004108.

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Phenolic compounds are a group of organic chemicals present in the wastewaters of many synthetic industrial processes. Due to their extreme toxicity to man and animals, and deleterious impact on the environment, a range of techniques exist for the effective treatment and disposal of these pollutants. Biological degradation using microbial enzymes presents a valuable alternative to conventional wastewater treatment systems. This research was therefore initiated to investigate the polyphenol oxidase enzyme system and the feasibility of its application for effluent treatment and studies in organi

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26

Kyei, Mary Abena. "Digestive proteases from the stomachless cunner fish (Tautogolabrus adspersus) : preparation and use as food processing aid." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0015/MQ37309.pdf.

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27

Hossain, Abzal. "Inhibition of tyrosinase activity by metallothionein from Aspergillus niger." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0015/MQ55068.pdf.

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28

Kiralp, Senem. "Synthesis Of Conducting Block Copolymers And Their Use In The Immobilization Of Invertase And Polyphenol Oxidase Enzymes." Phd thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/12604912/index.pdf.

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A new thiophene derivative containing menthyl group (MM) was synthesized and polymerized via chemical and electrochemical methods. Polymers obtained and MM itself were used to synthesize copolymers with pyrrole under conditions of constant potential electrolysis. Cyclic Voltammetry, thermal analysis and scanning electron microscopy analyses were performed for the characterization of samples. Immobilization of invertase and polyphenol oxidase enzymes was performed in the matrices obtained via copolymerization of MM with pyrrole. Immobilization was carried out via entrapment of enzyme in matric

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29

Vázquez, Daniel. "Effects of genotype and environment on polyphenol oxidase activity and related properties of red and white wheats." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0021/MQ56149.pdf.

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30

Goetsch, Patricia-Ann. "The microbial production of polyphenol oxidase enzyme systems and their application in the treatment of phenolic wastewaters." Thesis, Rhodes University, 1993. http://hdl.handle.net/10962/6190.

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Phenolic compounds are a group of organic chemicals present in the wastewaters of many synthetic industrial processes. Due to their extreme toxicity to man and animals, and deleterious impact on the environment, a range of techniques exist for the effective treatment and disposal of these pollutants. Biological degradation using microbial enzymes presents a valuable alternative to conventional wastewater treatment systems. This research was therefore initiated to investigate the polyphenol oxidase enzyme system and the feasibility of its application for effluent treatment and studies in organi

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31

Yildiz, Huseyin Bekir. "Synthesis And Characterization Of Conducting Copolymers Of Thiophene Ended Poly(ethyleneoxide): Their Electrochromic Properties And Use In Enzyme Immobilization." Phd thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/12608123/index.pdf.

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Thiophene ended poly(ethylene oxide) (ThPEO) and random copolymer (RPEO) of 3-methylthienyl methacrylate and p-vinylbenzyloxy poly (ethyleneoxide) units were synthesized chemically. Further graft copolymerization of RPEO and ThPEO with pyrrole (Py) and thiophene (Th) were achieved in H2O - sodium dodecylsulfate (SDS), H2O - p-toluenesulphonic acid (PTSA) and acetonitrile (AN) - tetrabutylammonium tetrafluoroborate (TBAFB) solvent electrolyte couples via constant potential electrolyses. Characterizations were performed by cyclic voltammetry (CV), nuclear magnetic resonance spectroscopy (NMR), a

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32

Crumière, Fabienne. "Inhibition of enzymatic browning in food products using bio-ingredients." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0034/MQ64338.pdf.

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33

Gouzi, Hicham. "Extraction et caractérisation biochimique des polyphénol oxydases de champignons et leur application en biocatalyse supportée." Electronic Thesis or Diss., Paris 6, 2014. http://www.theses.fr/2014PA066668.

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Ce travail concerne l'extraction d'enzymes de la famille des polyphénol oxydases à partir de champignons, leur caractérisation biochimique et leur immobilisation dans des matrices solides. Ces enzymes ont tout d'abord été extraites du champignon de Paris (Agaricus bisporus) puis partiellement purifiées. Une étude de leur activité enzymatique, de leur domaine de stabilité et de leur comportement thermique a été effectuée, ainsi que l'identification d'inhibiteurs. Cette approche a été étendue à la polyphénol oxydase de la truffe de désert (Terfezia leonis Tul.). Ces deux enzymes ont ensuite été

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34

WANG, GAI. "Effect of Frozen Storage on Antioxidant Capacity, Polyphenol Oxidase Activity, and Phenolic and Flavonoid Content and Color of Pawpaw Pulp." Ohio University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1373373703.

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35

Moore, Nina L. "Distribution of polyphenol oxidase in cultured hyphae of coriolus versicolor. A wood decay fungus and partial purification of the enzyme." DigitalCommons@Robert W. Woodruff Library, Atlanta University Center, 1992. http://digitalcommons.auctr.edu/dissertations/3589.

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Coriolus versicolor, a white-rot Basidiomycete, secretes lignocellulolytic enzymes and polyphenol oxidase (PPO). While the former degrade wood polymers, the latter converts diphenols to diquinones. Because C. versicolor can be ‘batch-cultured’, overproduction and enhanced secretion of agriculturally/commercially useful enzymes are feasible. Reported are attempts to: define the timed-appearances of intra- and extracellular PPO, achieve possible PPO substrate induction, ascertain its secretion route and partially purify extracellular PPO. Whereas two protein peaks (6 and 12 days in a 16 day time

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Barioto, Valquiria da Cruz Rodrigues. "Influência do contra-íon usado na eletrossíntese do polipirrol em sua resposta como biossensor eletroquímico após a imobilização da polifenol oxidase." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/88/88131/tde-24092009-144106/.

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Neste trabalho, foram fabricados biossensores amperométricos a partir do uso da polifenol oxidase (PFO), obtida do abacate como fonte enzimática, imobilizada em filmes de polipirrol (PPI) e que foram eletrossintetizados em meio de três diferentes eletrólitos de suporte (NaCl e NaClO4 e NaDDS). O método de imobilização enzimática foi o da adsorção, sendo a solução de enzima adicionada à solução com o pirrol e o eletrólito durante o processo de eletropolimerização. Os filmes de PPI/PFO foram caracterizados por técnicas eletroquímicas, principalmente por voltametria cíclica. A detecção de compost

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Arruda, Izabela Gutierrez de. "Biossensores amperométricos fabricados a partir de eletrodos enzimáticos de polifenol oxidase para a detecção de pesticidas." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/18/18158/tde-06102016-172656/.

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A utilização descontrolada de pesticidas tem provocado no decorrer dos anos a intoxicação de milhares de pessoas no mundo, uma vez que, seus resíduos têm sido depositados em alimentos, em solos e em ambientes aquáticos. Assim, a construção de duas novas plataformas sensoras para a detecção de pesticidas é o objetivo desse trabalho. Na primeira plataforma foi utilizado o polieletrólito catiônico polietilenoimina (PEI) em conjunto com o polissacarídeo extracelular algal (PSE) produzido pela microalga criptofícea Cryptomonas tetrapirenoidosa preparados através da técnica de deposição \"spin-coati

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Barioto, Valquiria da Cruz Rodrigues. "Filmes de polipirrol como matrizes para a imobilização das enzimas fitase e polifenol oxidase e aplicados como biossensores." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/18/18158/tde-13012015-104218/.

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Este trabalho teve como objetivo o desenvolvimento de biossensores eletroquímicos baseados na imobilização de duas enzimas diferentes em filmes de polipirrol (PPI) eletrodepositados, a fitase e a polifenol oxidase (PFO), esta última na forma de extrato bruto do fruto de abacate. Como a fitase hidrolisa cataliticamente ácido fítico (AF) em íons fosfatos, foram preparados biossensores por imobilização da enzima sobre filmes de PPI para a detecção indireta de ácido fítico via íons fosfatos. Foram utilizados dois métodos de imobilização; no primeiro, a enzima, fitase, foi imobilizada ao filme de P

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Golveia, Jhéssica Cavalcante de Souza. "Indução de lacase de Pycnoporus sanguineus CCT 4518 induzida por resíduos agroindustriais e ensaio de biorremediação de estrogênio sintético (EE2)." Universidade Federal de Goiás, 2016. http://repositorio.bc.ufg.br/tede/handle/tede/6107.

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Button, Kimberly. "Processing sweet potatoes into french fries." Kansas State University, 2015. http://hdl.handle.net/2097/20496.

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Master of Science<br>Food Science Institute - Animal Sciences & Industry<br>Fadi M. Aramouni<br>Sweet potatoes are a significant crop and are popular among consumers, particularly as french fries. Because the processing steps of making white potato french fries may be detrimental to the quality of a sweet potato fry, it is important to understand the impact of processing on quality and consumer acceptability. The variety of sweet potatoes can affect the texture, appearance, and consumer preference. Peeling processes have evolved from harsh lye treatments to more quick and efficient methods suc

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Stojanovic, Jelena. "Determination of polyphenol oxidase (PPO) activity, anthocyanin contents and the phytonutrient changes in blueberry juice as influenced by different processing methods." Diss., Mississippi State : Mississippi State University, 2008. http://library.msstate.edu/etd/show.asp?etd=etd-05292008-172900.

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Azevedo, Andreia Cristiane Souza. "Estudo das enzimas oxidativas e presença de compostos bioativos em mangas (Mangifera indica L.) produzidas no Brasil." [s.n.], 2006. http://repositorio.unicamp.br/jspui/handle/REPOSIP/256708.

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Orientador: Glaucia Maria Pastore<br>Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos<br>Made available in DSpace on 2018-08-05T16:35:23Z (GMT). No. of bitstreams: 1 Azevedo_AndreiaCristianeSouza_D.pdf: 1028995 bytes, checksum: 6758be8c224c65879df45396853361cf (MD5) Previous issue date: 2006<br>Resumo: Diversos estudos epidemiológicos têm mostrado que o consumo regular de frutas e vegetais reduz a incidência de doenças crônico-degenerativas. A manga (Mangifera indica L.) é amplamente encontrada em regiões tropicais e subtropicais, é uma fruta popular

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Guimarães, Daniela Paiva. "Estudo bioquimico de algumas caracteristicas da peroxidase, polifenoloxidase e pectinametillesterase de amora preta (Rubus spp)." [s.n.], 2006. http://repositorio.unicamp.br/jspui/handle/REPOSIP/322519.

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Orientador: Helia Harumi Sato<br>Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos<br>Made available in DSpace on 2018-08-05T16:51:34Z (GMT). No. of bitstreams: 1 Guimaraes_DanielaPaiva_M.pdf: 17454686 bytes, checksum: 95c3e2eb551f853fabd105f2d0d03911 (MD5) Previous issue date: 2006<br>Mestrado<br>Mestre em Ciência de Alimentos

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Valiev, Abduvali. "Enzymology." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/12608217/index.pdf.

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In this study, two symbiotic fungi of Southern Pine Beetle (SPB), Entomocorticium peryii and Entomocorticium sp.A were evaluated in terms of polyphenol oxidase (PPO) production. The effect of different inhibitors, inducers and assay parameters such as temperature and pH on enzyme activity were investigated and maximum PPO activity was observed at 30&deg<br>C, pH 8.0 and when tannic acid was used as an inducer. Copper-chelator salicyl hydroxamic acid (SHAM) and pcoumaric acid, both indicated as inhibitors of tyrosinase and catechol oxidase significantly reduced the activity. For biochemical cha

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Pigatto, Gisele. "Estudo da aplicação da tirosinase vegetal no tratamento de efluentes e verificação da genotoxicidade do efluente tratado em células vegetais." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/9/9135/tde-10042013-164118/.

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Os problemas ambientais relacionados à crescente atividade industrial têm gerado preocupações aos órgãos governamentais e entidades de proteção ambientais, sendo necessários estudos de base que busquem novas alternativas para a recuperação de áreas poluídas e a solução de problemas operacionais relacionados com as técnicas empregadas. Um dos compostos mais encontrados em diversos efluentes industriais, principalmente de indústrias bioquímico-farmacêuticas, é o fenol que provoca um impacto danoso no ambiente devido ao fato de ser um poluente tóxico. O presente trabalho propõe, portanto, avaliar

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Zhang, Lin. "The Effects of High Pressure Processing, Browning Additives, and Storage Period on the Inactivation of Polyphenol Oxidase in Nine Varieties of Pawpaw (Asimina Triloba L.) Pulp." Ohio University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1462352198.

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Matsui, Kátia Nicolau. "Inativação das enzimas presentes na água de coco verde (Cocos nucifera L.) por processo térmico através de microondas." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/3/3137/tde-15092006-180716/.

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Neste trabalho, o forno de microondas focalizadas (CEM, Star System 2) e o forno de microondas doméstico adaptado (CCE, MW - 850) foram utilizados para o processo térmico descontínuo e contínuo, respectivamente para reduzir a atividade da POD e PFO presentes na água de coco. No processo descontínuo um sensor de fibra óptica permaneceu em contato direto com as amostras, o que permitiu a obtenção de perfis precisos da temperatura em função do tempo e a determinação dos parâmetros cinéticos D e z para as enzimas, no intervalo de temperatura entre 50 e 100 °C. No processo contínuo, a aquisição dos

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GUERRA, Isabel Cristina Solano. "Caracterização parcial de enzimas oxidativas e quantificação de compostos fenólicos em frutos de três genótipos de cajazeira (Spondias mombin L.) nos estádios de maturação verde e maduro." Universidade Federal Rural de Pernambuco, 2009. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/6349.

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Submitted by (lucia.rodrigues@ufrpe.br) on 2017-02-15T11:55:14Z No. of bitstreams: 1 Isabel Cristina Solano Guerra.pdf: 942122 bytes, checksum: 5683fa570313b58392de0fb4c7778348 (MD5)<br>Made available in DSpace on 2017-02-15T11:55:14Z (GMT). No. of bitstreams: 1 Isabel Cristina Solano Guerra.pdf: 942122 bytes, checksum: 5683fa570313b58392de0fb4c7778348 (MD5) Previous issue date: 2009-09-16<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES<br>This study aimed to partially characterize the oxidative enzymes and quantify the phenolic compounds in fruits of three cultivars

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Melo, Geraldo Aclecio. "Purificação da enzima polifenoloxidase do cafeeiro, sua relação com resistencia a pragas e o controle da sintese de seu principal substrato, o acido clorogenico." [s.n.], 2005. http://repositorio.unicamp.br/jspui/handle/REPOSIP/315483.

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Orientador: Paulo Mazzafera<br>Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia<br>Made available in DSpace on 2018-08-05T10:18:49Z (GMT). No. of bitstreams: 1 Melo_GeraldoAclecio_D.pdf: 1320706 bytes, checksum: 5f501b7dd60a44ae72341950498d75f7 (MD5) Previous issue date: 2005<br>Resumo: Polifenoloxidase - PFO (EC 1.14.18.1 ou EC 1.10.3.2) é uma enzima de ampla distribuição entre as plantas e catalisa a hidroxilação de monofenóis a o-difenóis e a oxidação destes para o-diquinonas. Sua função em plantas tem sido relacionada a mecanismos de defesa contra patógenos e p

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Hojo, Ellen Toews Doll [UNESP]. "Aplicação de métodos combinados na conservação da qualidade de lichias ‘Bengal’." Universidade Estadual Paulista (UNESP), 2010. http://hdl.handle.net/11449/105208.

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Made available in DSpace on 2014-06-11T19:33:38Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-08-13Bitstream added on 2014-06-13T21:06:45Z : No. of bitstreams: 1 hojo_etd_dr_jabo.pdf: 1539570 bytes, checksum: 9a8c4375124457a8e811faf5f3693cc6 (MD5)<br>Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)<br>Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)<br>Visando prolongar a vida útil da lichia, principalmente quanto à manutenção da cor e da qualidade, executaram-se experimentos para avaliar a eficiência dos tratamentos hidrotérmico e com solução de áci

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