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both STR and EMR, derive the kinetic parameters on the basis of observed experimental data, and compare the catalytic performance of such systems in terms of substrate conversion and productivity. Kinetic modeling In this section we introduce a kinetic

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The application of immobilized enzyme for catalyzing various biotransformation processes is a widely used approach at present. This work mainly focused on the immobilization of polygalacturonase from Aspergillus niger Van Tieghem (MTCC 3323) on Nylon-6 by covalent binding, keeping in view its applicability in apple juice clarification. The immobilized enzyme was characterized in terms of kinetic parameters, thermal stability and reusability. The enzyme was immobilized onto glutaraldehyde-activated Nylon-6 by covalent binding and the efficiency of immobilization was found to be 40%. The immobilization yielded a protein loading of 70 μg g −1 of Nylon-6. Immobilized enzyme showed maximum activity at a temperature of 50 °C and pH 5.0. The enzyme was stable between pH 4.0–5.5. The immobilized enzyme could be reused through 4 cycles with almost 50% retention of its original activity. It had increased thermostability over its soluble form at 25 °C and 45 °C. Kinetic parameters K m and V max were found to be 7.6 mg ml −1 and 41.66 μmol of galacturonic acid/ml/min, respectively. The immobilized enzyme when used for apple juice clarification showed about 50% increase in transmittance of apple juice at 650 nm. This increase was observed at enzyme concentration of 20 U ml −1 apple juice, temperature 50 °C and incubation time of one hour. The optimization of these factors, which affect the stability and productivity of the immobilized system, resulted in an increase in enzyme stability and the possibility of economic application of immobilized enzyme at large scale apple juice clarification.

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The aim of this study was to determine the stimulatory effect of honey addition on fermentation activity of Lactobacillus casei Lc-01 in cow’s and goat’s milk. Two monofloral honey types, dark-coloured chestnut and light-coloured acacia honey were added to cow’s and goat’s milk before fermentation. Different mathematical and statistical models were used to describe the kinetics of fermentation in all analysed samples. The basic hypothesis of this study was that addition of honey could influence fermentation kinetics in both types of milk. Comprehensive kinetic analyses suggested complex interaction between all components in fermented milk samples. The results presented in this paper showed that addition of both types of honey had a stimulatory effect on the growth of Lactobacillus casei Lc-01 in cow’s and goat’s milk. Addition of acacia honey significantly stimulated (P<0.05) the growth of Lactobacillus casei Lc-01 in cow’s and goat’s milk. This resulted in higher number of Lactobacillus casei cells, as well as in lower pH values of the samples with addition of acacia honey. Furthermore, goat’s milk was fermented faster than cow’s milk. Calculated values of selected kinetic parameters showed that the critical period of fermentation kinetics, when influence of honey proved stimulatory, was between 10th and 20th hour of the fermentation.

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Benkeblia, N. & Shiomi, N. (2006): Hydrolysis kinetic parameters of DP 6, 7, 8, and 9–12 fructooligosaccharides (FOS) of onion bulb tissues. Effect of temperature and storage time. J. agric. Fd

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some different temperatures by the kinetic parameters. Fisheries Set , 66 (1), 161-165. Determination of K-value using freshness prediction of the finfishes stored at some different temperatures by the kinetic parameters

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The biological and toxicological importance of molybdenum in the environment and in the nutrition of plants, animals and man

Part IV: The molybdenum intake of adults with mixed and vegetarian diets in Germany and Mexico (duplicate portion studies)

Acta Alimentaria
Authors: M. Anke, S. Holzinger, M. Seifert, R. Müller, and U. Schäfer

Thompson, K.H., Scott, K.C. & Turnlund, J.R. (1996): Molybdenum metabolism in men with increasing molybdenum intakes: Changes in kinetic parameters. J. appl. Physiol. , 81 , 1404–1409. Turnlund J

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Acta Alimentaria
Authors: M. Ferreira, S. Pereira, A. Almeida, R. Queirós, I. Delgadillo, J. Saraiva, and A. Cunha

. , R ITZ , M. , D ELÉPINE , S. , J UGIAU , F. , F EDERIGHI , M. & D E LAMBALLERIE , M. ( 2006 ): Influence of kinetic parameters of high pressure processing on bacterial inactivation in a buffer system . Int. J. Food Microbiol. , 106

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. Ho , Y. S. ( 2004 ) Comment on “An alternative Avrami equation to evaluate kinetic parameters of the interaction of Hg (II) with thin chitosan membranes” . J. Colloid. Interface Sci . 272 ( 1 ): 249 – 250

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). Equations and λ (649 and 665 nm) were modified due to changing the solvent for ethanol 95% (v v –1 ) ( L ichtenthaler & W ellburn , 1983 ). 1.7 Determination of kinetic parameters The exponential growth phase (EGP) was identified as the linear region on an

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°C, while constant degradation at 80 °C was found. Consequently, degradation kinetic parameters were estimated for the higher temperature according to equations (1) and (2) . Fig. 4. Isothermal degradation of red cabbage anthocyanins using the first

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