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  • 1
    Electronic Resource
    Electronic Resource
    Decrease of tannin content in canola meal by an enzyme preparation from Trametes versicolor (1996)
    Springer
    Biotechnology letters 18 (1996), S. 309-314 
    Details
    ISSN: 1573-6776
    Source: Springer Online Journal Archives 1860-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary An enzyme preparation from Trametes versicolor was used to decrease the tannin content in commercially available canola meal. More than 80% reduction was observed after 30 min of processing using an enzyme concentration equivalent to 20 nkat. The process was optimal at pH 6.0 and at a temperature of 50°C. The buffering capacity of canola meal was shown.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00142950
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  • 2
    Electronic Resource
    Electronic Resource
    Comparison of three methods for the determination of sinapic acid ester content in enzymatically treated canola meals (1996)
    Springer
    Applied microbiology and biotechnology 45 (1996), S. 530-537 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  The enzymatic reduction of sinapic acid ester content in canola meal using polyphenol oxidase from the fungus T. versicolor was investigated. To determine the effectiveness of this new process, the results obtained using two spectrophotometric methods and an HPLC analytical method for assaying sinapic acid ester content in the treated and untreated meals were compared. It was found that all the methods gave practically the same results when the samples from untreated canola meals were analysed. However, both of the spectrophotometric methods overestimated the sinapic acid ester content in the enzymatically treated meal by 7%–20%, as compared to the results obtained using HPLC. It was found that the sensitivity limits for the spectrophotometric methods used for the determination of sinapic acid ester content in enzymatically treated canola meals were 2.67 g and 1.47 g phenolics/kg meal for the direct and chemical spectrophotometric methods respectively. A correlation between the results obtained using the spectrophotometric and HPLC methods is given. The enzymatic treatment resulted in a negligible amount of phenolics in the treated meal.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00578467
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  • 3
    Electronic Resource
    Electronic Resource
    Comparison of three methods for the determination of sinapic acid ester content in enzymatically treated canola meals (1996)
    Springer
    Applied microbiology and biotechnology 45 (1996), S. 530-537 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The enzymatic reduction of sinapic acid ester content in canola meal using polyphenol oxidase from the fungusT. versicolor was investigated. To determine the effectiveness of this new process, the results obtained using two spectrophotometric methods and an HPLC analytical method for assaying sinapic acid ester content in the treated and untreated meals were compared. It was found that all the methods gave practically the same results when the samples from untreated canola meals were analysed. However, both of the spectrophotometric methods overestimated the sinapic acid ester content in the enzymatically treated meal by 7%–20%, as compared to the results obtained using HPLC. It was found that the sensitivity limits for the spectrophotometric methods used for the determination of sinapic acid ester content in enzymatically treated canola meals were 2.67 g and 1.47 g phenolics/kg meal for the direct and chemical spectrophotometric methods respectively. A correlation between the results obtained using the spectrophotometric and HPLC methods is given. The enzymatic treatment resulted in a negligible amount of phenolics in the treated meal.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00578467
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  • 4
    Electronic Resource
    Electronic Resource
    Decrease of phenolic content in canola meal using a polyphenol oxidase preparation from Trametes versicolor: Effect of meal saccharification (1998)
    Springer
    Biotechnology techniques 12 (1998), S. 31-34 
    Details
    ISSN: 1573-6784
    Source: Springer Online Journal Archives 1860-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract A process to decrease the phenolic content of canola meal using a polyphenol oxidase preparation from Trametes versicolor was carried out in the presence and absence of cell wall solubilizing enzymes. Eighty five percent of the polysaccharide fraction of the cell wall of canola meal was solubilized in the process. A complete decrease in phenolic content was observed in the presence of xylanase or cellulase preparations after 16 and 36 hours of treatment, respectively. The initial rates of the process decreased by 10% and 5% in the presence of xylanase and cellulase preparations, respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008847324408
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  • 5
    Electronic Resource
    Electronic Resource
    Conversion of catechin and tannic acid by an enzyme preparation from Trametes versicolor (1996)
    Springer
    Biotechnology letters 18 (1996), S. 771-774 
    Details
    ISSN: 1573-6776
    Source: Springer Online Journal Archives 1860-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary An extracellular enzyme preparation produced by the white rot fungus Trametes versicolor transformed catechin and tannic acid. Optimum conversion of catechin was at 60°C and pH 6.0.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00127886
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  • 6
    Electronic Resource
    Electronic Resource
    Modeling the enzymatic transformation of 3,5-dimethoxy,4-hydroxy cinnamic acid by polyphenoloxidase from the white-rot fungus Trametes versicolor (1996)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 51 (1996), S. 249-259 
    Details
    ISSN: 0006-3592
    Keywords: sinapic acid ; polyphenoloxidase ; Trametes versicolor ; reaction mechanism ; mathematical model ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A mechanism for transforming sinapic acid by a polyphenoloxidase from Trametes versicolor was investigated using changes in sinapic acid and oxygen concentrations during the reaction. The experiments were performed in a closed system without supplemental oxygen. The effects of temperature and initial oxygen concentration on the reaction rates were examined. To compare the obtained results with those from spectrophotometric studies, some runs were performed using an open system with supplemental oxygen. Sinapic acid transformation can be described by the Theorell-Chance Bi-Bi or Ordered Bi-Bi mechanisms. This reacting system consisted also of additional enzymatic reactions between the products of sinapic acid transformation and oxygen. A mathematical model was developed using four ordinary differential equations that represent the Theorell-Chance Bi-Bi mechanism with three alternate substrates. Model parameters (i.e., rate constants) were determined using the data collected at three different temperatures. On the basis of the transition state theory, relationships between these constants and temperature were established. It is shown that, in the open system, the observed change in the enzyme activity at higher temperatures was caused by two opposing phenomena: an Arrhenius effect which increased the rate, and a solubility effect which reduced the rate due to a lower oxygen concentration. This finding allows us to recommend better conditions for spectrophotometric methods, the assay most commonly used to evaluate this and similar enzymes. © 1996 John Wiley & Sons, Inc.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Transformation of 3,5-dimethoxy,4-hydroxy cinnamic acid by polyphenol oxidase from the fungus Trametes versicolor: Product elucidation studies (1998)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 57 (1998), S. 694-703 
    Details
    ISSN: 0006-3592
    Keywords: Trametes versicolor ; sinapic acid ; dehydrodisinapic acid dilactone ; polyphenol oxidase ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Sinapic acid (SA), 3,5-dimethoxy,4-hydroxy cinnamic acid, was incubated with a crude polyphenol oxidase from the fungus Trametes versicolor. Some products of this transformation were isolated and their structures identified using mass spectrometry, nuclear magnetic resonance and Fourier transform infrared spectroscopy, and X-ray crystallography. It was found that the enzymatic oxidation of SA includes two distinct phases. In the initial phase SA is enzymatically transformed to r-1H-2c,6c-bis-(4′-hydroxy-3′,5′-dimethoxyphenyl)-3,7-dioxabicyclo-[3,3,0]-octane-4,8-dione, dehydrodisinapic acid dilactone. The mechanism of this reaction may involve coupling of two phenoxy radicals by the β-β mode and subsequent intramolecular nucleophilic attack. In the second phase dehydrodisinapic acid dilactone is transformed by polyphenol oxidase into several intermediate products, including 4-(4-(3,5-dimethoxy-4-oxo-2,5-cyclohexadienyliden)-1,4-dihydroxy-(E)-2-butenylidene)-2,6-dimethoxy-2,5-cyclohexadien-1-one. The final product of the overall transformation of SA is 2,6-dimethoxy-p-benzoquinone. The obtained results were used to propose a part of the transformation pathway for the enzymatic oxidation of SA by polyphenol oxidase. © 1998 John Wiley & Sons, Inc. Biotechnol Bioeng 57: 694-703, 1998
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Transformation of 3,5-dimethoxy-4-hydroxy cinnamic acid and its derivatives using enzyme from white-rot fungus Trametes versicolor: Enzyme characteristics and its application (1996)
    Chichester : Wiley-Blackwell
    Journal of Chemical Technology AND Biotechnology 65 (1996), S. 211-220 
    Details
    ISSN: 0268-2575
    Keywords: sinapic acid ; sinapine ; sinapaldehyde ; Trametes versicolor ; phenol oxidase ; canola meal ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Transformation of 3,5-dimethoxy-4-hydroxy cinnamic acid (sinapic acid), sinapaldehyde, sinapine and sinapoyl in the model system containing an enzyme secreted by the fungus Trametes versicolor was investigated. The affinity of this enzyme was highest for sinapic acid followed by sinapaldehyde and sinapine. The optimum temperature and pH for these transformations were 50°C and pH 3·3, 50°C and pH 4·5, 60°C and pH 4·0 for sinapaldehyde, sinapine, and sinapic acid, respectively. The apparent heat of the enzyme-sinapic acid complex formation is -2557·6 J mol-1. Higher concentrations of sinapine and sinapic acid caused enzyme inhibition. When canola meal was treated with this enzyme the phenolics content in this commodity was decreased by 90%.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Enzymatic decrease in the phenolic content of canola meal using concentrated aqueous or aqueous/hexane slurries (1998)
    Berlin : Wiley-Blackwell
    Acta Biotechnologica 18 (1998), S. 95-106 
    Details
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: An enzymatic process to decrease the phenolic content in canola meal was investigated. The new method was based on the addition of an enzyme preparation from the white-rot fungus Trametes versicolor to concentrated meal-buffer slurries. This approach eliminated the extraction of the valuable meal components such as proteins and carbohydrates. Two systems were considered: (i) slurries with canola meal concentrations higher than 33% [w/v]; (ii) slurries with canola meal concentrations equal to or less than 12.5% [w/v] with n-hexane as the main component of the continuous phase.The concentration of sinapic acid esters decreased by 99% after a 1.5, 2 and 3 hour long treatment of the meal with an initial moisture content of 75% at 90°C, 70°C and 50°C, respectively. The process was carried out at temperaturs as high as 110°C. Both the enzyme and the moisture concentrations influenced the enzymatic process and their action was coupled. The concentration of oxygen strongly affected the process.The enzymatic process was able to be carried out in the presence of hexane as the main component of the continuous phase. The optimum temperature for such a process was 30-40°C, At 30°C, after 1 h of treatment, the meal phenolic content was decreased by 97%. The water uptake by the meal was diminished in the presence of hexane.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/abio.370180202
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  • 10
    Electronic Resource
    Electronic Resource
    Stability of a polyphenol oxidase from the white-rot fungus Trametes versicolor in the presence of canola meal (1999)
    Berlin : Wiley-Blackwell
    Acta Biotechnologica 19 (1999), S. 91-100 
    Details
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: The stability of a polyphenol oxidase (PPO) preparation from the white-rot fungus Trametes versicolor during a process for the enzymatic decrease of the phenolic content of commercial canola meal (CM) was investigated. The effects of temperature, pH, protein origin and concentration, and meal particles were considered. The results showed that the thermal stability of the enzyme preparation was significantly increased in the presence of CM. The half-life times for the enzyme preparation, pre-incubated with CM at 50, 60, 70 and 75°C, were 45, 10.5, 3.5 and 1.5 hours, respectively; this represents an increase in the thermal stability of the enzyme preparation of up to four times in the presence of CM compared to the stability in the absence of CM. This effect was caused by the protective actions of both the CM particles and CM proteins, with the former responsible for 90% of the observed effect. The thermal stability of the enzyme in the presence of CM, from which 20% of the extractable proteins was extracted, was 5% lower compared to the stability in the presence of untreated CM. Changes in pH level from 5.0 to 3.2 resulted in a loss of stability comparable to that observed when the pre-incubation temperature was increased from 50 to 70°C.A semi-empirical model describing the changes in the concentration of the active enzyme pre-incubated in the presence and absence of CM at various incubation temperatures was proposed. A very good agreement between the model and experimental data was obtained. The proposed model, together with a general set of model parameters, can be used as a tool for the optimization of a process for the upgrade of CM by enzymatically decreasing the meal's phenolic content.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/abio.370190202
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