Harun Parlar

University of Technology Munich, München, Bavaria, Germany

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Publications (250)480.75 Total impact

  • Harun Parlar · Albrecht Friess
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    ABSTRACT: In this work the effects of non- Thermal low electric treatment on the excretion of toxicologically relevant chlorophenols from 10 probands was investigated. After the treatment with PowerTube QuickZap® (level 3, for 21 min minimum) the blood and urine samples were examined for chlorophenols including their metabolites, such as chloro- phenolglucoronides. The obtained results showed a significant elimination of these substances in all investigated proband samples after the therapy. These findings point out that there is a possibility to eliminate these hazardous substances rapidly from the human body using low electric treatment.
    No preview · Article · Jan 2014 · Fresenius Environmental Bulletin
  • Yen-Chih Chen · Harun Parlar
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    ABSTRACT: Foam fractionation is a promising method for separation and concentration of biochemicals. It is simple, easily scalable, inexpensive, and environment friendly. Foam fractionation thus represents an alternative to the traditional methods used for immunoglobulin enrichment. However, little, if any, literature exists documenting the utilization of foam fractionation in the enrichment of immunoglobulins. Milk were utilized as an immunoglobulin source to serve as examples of a real system in this study. The investigation examined the effects of varying five different process parameters: the initial pH value, the initial concentration of immunoglobulin, the nitrogen flow rate, the column height, and the foaming time. Experimental results demonstrated that immunoglobulin could effectively be enriched from milk by foam fractionation. The maximum enrichment ratio with pretreatment (using pH 4.6 precipitation) was 6.30 along with a more than 92 % recovery for IgG and an enrichment ratio of 5.1 with 85 % recovery for IgM.
    No preview · Article · May 2013 · Applied biochemistry and biotechnology
  • Yen-Chih Chen · Harun Parlar
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    ABSTRACT: Traditional immunoglobulin enrichment methods, based mostly on chromatographic processes, generally involve costly purification and lead to expensive final products. As such, there is a definite need to develop techniques capable of increasing capacity and decreasing total costs. Foam fractionation represents a promising method for separation and concentration of biochemicals. It is simple, easily scalable, inexpensive and environmentally friendly. Foam fractionation thus represents an alternative to the traditional methods used for immunoglobulin enrichment. However, little, if any, literature exits documenting the utilization of foam fractionation in the enrichment of immunoglobulins.To establish a model system, the foam fractionation of immunoglobulin was studied with the aid of albumin as a foaming agent. Response surface design experiments examined the effect of various initial concentrations of immunoglobulin, pH values and nitrogen flow rates on the enrichment ratio and recovery in a model system by foam fractionation.The established prediction equations for both the enrichment ratio and immunoglobulin recovery were verified through validation experiments. The predicted responses were an enrichment ratio of 5.5 and recovery of 96% for IgG, while the experimental values were 5.47% and 95.6%, respectively, which match quite well.
    No preview · Article · Apr 2013 · Separation and Purification Technology
  • Friedhelm Korte · Harun Parlar
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    ABSTRACT: In order to estimate the effects of chemicals on the quality of the different environmental compartments, primarily ecochemical and ecotoxicological data are desirable. In addition to their production levels and use patterns, knowledge of their toxicological effects and behavior under biotic and abiotic conditions are necessary. These kinds of experiments give, on the one hand, sufficient data on the stability of the chemicals in the environment. On the other hand, they make also possible to identify conversion products, which behave differently than the parent compounds. Under consideration of all these data, it is possible to describe a simple risk and hazard profile of chemicals. All risks can be excluded by these rapid methods. Further investigations, coupled with complex regulation, which places greater and unfounded responsibility on chemical industry, are not necessary. These kinds of regulations can be even repressive and counterproductive. This paper deals with these aspects and to try to find out, which present regulations are useful or not.
    No preview · Article · Jan 2013 · Fresenius Environmental Bulletin
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    ABSTRACT: Butterbur (Petasites) is an ancient plant which has been used for medical and edible purposes with its spasmolytic agents. However, toxic alkaloid content of the plant limits its direct usage. The paper covers the pyrrolizidine alkaloids (PAs) and butterbur themes in detail in order to display the outline of alkaloid-free plant extract production for medical and edible purposes. The toxic PAs and medicinal constituents of the plant are described with emphasis on analytics, physiological effects and published patent data on alkaloid free extract production. The analytics is based on several commonly used analytical methods including liquid chromatography-mass spectrometry, gas chromatography-mass spectrometry and enzyme linked immunoassay analysis of PAs and N-oxides based on published literature data of butterbur. The analyses of major medicinal constituents of butterbur are given and the physiological effects of these compounds have been discussed to attract attention to the importance of alkaloid-free extract production. The concentration distributions of the medicinal constituents and toxic PAs in different parts of the plant and the outcomes of the published patent data provide comprehensive information for proper plant raw-material selection and production of alkaloid-free butterbur extracts. The review is intended to guide researchers interested in medical plant extracts by providing comprehensive data on the medical plant butterbur and its chemical constituents.
    No preview · Article · Dec 2012 · Journal of pharmaceutical and biomedical analysis
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    ABSTRACT: There is a simple solution for preventing gushing: the danger potential of raw materials (malt) shpuld be known before production. Using the analysis methods (Weihenstephaner Test, Modified Carlsberg Test) developed by MEBAK, the gushing risk is assessed on the basis of the quantity fobbed over after shaking a bottle. As these gushing tests are not suitable for a rapid analysis, R&D Department of the Weihenstephan Research Center for Brewing and Food Quality has developed a novel analytical approach for rapid gushing prediction using combined particle analysis. The latest results of this new rapid analysis for determination the gushing risk are presented.
    No preview · Article · Aug 2012
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    ABSTRACT: Malsters and brewers can currently check malt raw material for its potential to trigger gushing, using two analytical methods according to MEBAK. The quantity of carbonated wort (malt extract) foamed over after bottle shaking is measured, this is used for determining the gushing potential of the malt. But investigations have shown that the gushing volume may vary, making it difficult to arrive at a precise figure. The Research Center Weihenstephan for Brewing and Food Quality has therefore developed new analytical approaches to quantify gushing (not only on the basis of the quantity foamed over).
    No preview · Article · Jun 2012
  • S. Berner · A. Friess · P. Ekici · H. Parlar
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    ABSTRACT: A new enrichment method for prion protein (PrPSc) from cattle brain on the basis of adsorptive bubble separation(ABS) using sodium dodecylsulfate (SDS) as surface active component was developed. The obtained results demonstrate, that prion protein (PrPSc) could be enriched 140 fold in the foam phase and determinate therefore very sensitive with officially accreditated rapid assay tests. By this way very weak contaminated brains, which lead to negative results in the routine analysis, could be positively tested.
    No preview · Article · Jan 2012 · Fresenius Environmental Bulletin
  • Perihan Ekici · Harun Parlar
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    ABSTRACT: With the help of the chiral multidimensional gas chromatography/ high resolution mass spectroscopy (CHRGCHRMS), photodieldrin(1) and its enantiomers (1a and 1b) could be detected in high levels in several fish and cod liver oil samples originated from different regions. The instrumental limits of detection were from 0.1 to 1.2 ng/mL and the response of the MS-detector was linear up to 150 ng/mL. In most samples, concentration of Photodieldrin (1) was significantly higher than other chlorinated hydrocarbon insecticides such as chlordane, a-HCH or o,pDDT. Its enantiomer ratios (ER) were nearly 1.0 in every samples, which indicates that photodieldrin (1) cannot be metabolized in aquatic systems or in fish species.
    No preview · Article · Jan 2012 · Fresenius Environmental Bulletin
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    ABSTRACT: Die einfachste Lösung, Gushing vorzubeugen, ist, die Rohstoffe (Malz) bereits vor der Produktion auf ihr Gefahrenpotenzial hin zu kennen. Mithilfe der von der MEBAK formulierten Analysenmethoden (Weihenstephaner Test, Modifizierter Carlsberg-Test) wird das Gushing-Risiko durch die übergeschäumte Menge nach dem Flaschen-schütteln bewertet. Weil mit diesen Gushing-Tests eine rasche Analyse nicht möglich ist, wurde in der F&E-Abteilung des Forschungszentrums Weihenstephan für Brau- und Lebensmittelqualität ein neuartiger analytischer Ansatz zur schnellen Vorhersage von Gushing mithilfe der kombinierten Partikelanalytik erarbeitet. Aktuelle Ergebnisse dieser neuen Schnellanalyse zur Bestimmung des Gushing-Risikos werden vorgestellt.
    No preview · Article · Jul 2011
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    ABSTRACT: Zurzeit können Mälzer und Brauer den Rohstoff Malz durch zwei Analysenmethoden der MEBAK auf ihr Gefährdungspotenzial für Gushing prüfen. Hierfür wird die übergeschäumte Menge der karbonisierten Würze (Malzextrakt) nach dem Flaschenschütteln ermittelt, mit der das Gushing-Potenzial des Malzes bestimmt wird. Jedoch zeigen Untersuchungen, dass die Überschäummenge schwanken kann, was eine präzise Bestimmung erschwert. Deshalb wurden am Forschungszentrum Weihenstephan für Brau- und Lebensmittelqualität neue analytische Ansätze entwickelt, Gushing (nicht alleine durch die übergeschäumte Menge) zu quantifizieren.
    No preview · Article · Jun 2011
  • Jean Titze · Vladimir Ilberg · Harun Parlar

    No preview · Conference Paper · May 2011
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    ABSTRACT: Durch das Gushing-Jahr 2008 stieg das Interesse an Vorhersagetests, um das roh­stoffbedingte Gushing-Risiko noch vor der Rohstoffverarbeitung und Bierproduktion einschätzen zu können. Am Forschungs­zentrum Weihenstephan für Brau- und Lebensmittelqualität (FZW) werden zwei Analysenmethoden, Modifizierter Carlsbergtest (MCT) und Weihenstephaner Test (WT, auch Gushing-Schnelltest oder Donhauser-Test genannt), nach Mittel­europäischer Brau- und Analysenkommission e. V. (MEBAK) durchgeführt, um mit ihnen das Gushing-Potenzial von Malzen detektieren zu können. Untersuchungen der F&E-Abteilung des Forschungszentrums ergaben, dass beide Gushing-Tests mit ein und demselben Malz unterschiedliche oder gar gegensätzliche Ergebnisse erzeugen können. Dieser Beitrag diskutiert Gründe für die Unterschiede und stellt neue Erkenntnisse über die Entstehung und Unterdrückung von Gushing im Maisch- und Kochprozess zusammen.
    No preview · Article · May 2011
  • Source
    Ali Fanous · Angelika Görg · Harun Parlar
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    ABSTRACT: In this work we examined the effect of non-thermal low electric treatment on the protein expression of Sac-charomyces cerevisiae. The electric field was produced from therapeutic device Powertube QuickZap, which is in-tended for the electronic stimulation of nerves. It is used for self-treatment of symptoms and pain. Previous expe-riments have shown that low frequency electric or mag-netic fields cause changes in protein induction. The present study con-firms these observations. Two-dimensional gel electrophoresis (2-DE), Progenesis SameSpots software and matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS) were used to examine changes in protein expression. In response to 3 hours non-thermal low electric field exposure, the enzyme homoserin dehydrogenase was overexpressed. This result suggests that this enzyme may play an important role in the adaptation of Saccharomyces cerevisiae to electric stress. The role of an electric field as a co-stressing factor is discussed.
    Preview · Article · Jan 2011 · Fresenius Environmental Bulletin
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    ABSTRACT: Cobalt and silver are toxic for cells, but mechanisms of this toxicity are largely unknown. Analysis of Corynebacterium glutamicum proteome from cells grown in control and cobalt or silver enriched media was performed by two dimensional gel electrophoresis (2DE) followed by mass spectrometry. Our results indicate that the cell adapted to cobalt stress by inducing five defense mechanisms: Scavenging of free radicals, promotion of the generation of energy, reparation of DNA, reparation and biogenesis of Fe-S cluster proteins and supporting and reparation of cell wall. In response to the detoxification of Ag+ many proteins were up-regulated, which involved reparation of damaged DNA, minimizing the toxic effect of reactive oxygen species (ROS) and energy generation. Overexpression of proteins involved in cell wall biosynthesis (1,4-alpha-glucan branching enzyme and nucleoside-diphosphate-sugar epimerase) upon cobalt stress and induction of proteins involved in energy metabolism (2-methylcitrate dehydratase and 1, 2-methylcitrate synthase) upon silver demonstrate the potential of these enzymes as biomarkers of sub-lethal Ag+ and Co toxicity.
    No preview · Article · Oct 2010 · Journal of Environmental Science and Health Part B Pesticides Food Contaminants and Agricultural Wastes

  • No preview · Conference Paper · May 2010

  • No preview · Conference Paper · May 2010
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    ABSTRACT: Die Bildung von Diphenochinonen unter Bedingungen, unter denen die strukturisomeren Dioxine entstehen, fand bisher wenig Beachtung. Mit neuen Aufarbeitungs-und Analysenmethoden können nun chlorierte und nicht chlorierte Diphenochinone in unterschiedlichen Matrices bestimmt werden: Diese neue Klasse von Umweltchemikalien tritt immer in Begleitung von Dioxinen und Dioxin-Analoga auf. Mit den neuen Methoden steht damit ein weiteres Werkzeug zur Bestimmung von chlororganischen Verbindungen zur Verfügung.
    No preview · Article · May 2010 · Nachrichten aus der Chemie
  • Dirk Haller · Perihan Ekici · Albrecht Friess · Harun Parlar
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    ABSTRACT: Tweezing adsorptive bubble separation (TABS) was used as a method for the enrichment of matrix metalloproteinases (92-kDa type IV, gelatinase B (MMP-9)) and carboxypeptidase A (CPA) from dilute aqueous solutions. The method is based on the chelation of metalloenzymes applying 2-(carbamoylmethyl-(carboxymethyl)amino)acetic acid (ADA) coupled with an octyl part to form a surface active unit. MMP-9 could be enriched with an enrichment ratio of 12.0 and a recovery of 87.3%, and CPA could be enriched 18.8-fold and with 95.3% recovery. Both enzymes were enriched without significant losses of enzymatic activity. To verify that the enzymes were tweezed by ADA-C8 without abstraction of the zinc ions from the active center, TABS trials were additionally conducted with zinc ions in complex with ADA-C8, which revealed only negligible enrichment ratios of the enzymes (2.2 for MMP-9 and 0.2 for CPA). The results obtained impressively demonstrate that zinc-containing proteases can be enriched selectively and efficiently by TABS.
    No preview · Article · Mar 2010 · Applied biochemistry and biotechnology
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    ABSTRACT: Long-term stability is one of the most important quality criteria of beer. Three groups of measuring methods are available for its determination: real time tests, predictive tests and indicative tests. One of the most common methods is the predictive forcing test, which is a time-consuming method for accelerating beer ageing, e.g., at 0°C and 60°C. Two ways exist to perform this test: (1) follow-up of haze development and determination of the lag phase or (2) the measurement of haze values after several days. The first option was evaluated by performing a long-term Forcing test over a period of 4 months by analyzing a bottom-fermented beer. It was shown that the haze curve followed a typical course with a lag phase, an increase phase and a station-ary phase. Significant differences between the measurement after the cooling and the warm period were shown. In search of quicker methods and more accurate predictive indicators, the charge titration method was developed as an alternative to deter-mine the particle charge of filtered beers, whereupon the rela-tionship was elucidated between the increase in hazing and de-crease of potential along with the advanced aging of beer. The results showed that with increased particle size due to agglom-eration, the total charge decreased. In this array of trials, two differently stabilized beers were examined. Although both beers showed different haze values in the beginning (0.32 EBC and 1.30 EBC), the less stabilized beer had only 10 warm days and in contrast the beer with the good stabilization had over 20 warm days. With the help of the total charge, predictions were possible regarding the long-term stability of the beer.
    Full-text · Article · Jan 2010 · Journal- Institute of Brewing

Publication Stats

3k Citations
480.75 Total Impact Points

Institutions

  • 1979-2013
    • University of Technology Munich
      • Chair of Chemical-Technical Analysis and Chemical Food Technology
      München, Bavaria, Germany
  • 1988-1995
    • Universität Kassel
      • Department of Biochemistry
      Cassel, Hesse, Germany
  • 1974-1981
    • Deutsches Herzzentrum München
      München, Bavaria, Germany
  • 1971
    • University of Bonn
      Bonn, North Rhine-Westphalia, Germany