Modelling the kinetics of enzyme-catalysed reactions in frozen systems: the alkaline phosphatase catalysed hydrolysis of di-sodium-p-nitrophenyl phosphate

Terefe, Netsanet Shiferaw; Loey, Ann Van; Hendrickx, Marc

doi:10.1016/j.ifset.2004.05.004

Cited by 15 publications

(3 citation statements)

References 31 publications

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“…The FCS is known as a reaction medium having interesting features, such as the acceleration of reactions by freezing. − Although some results can be explained by freeze-concentration of the reactants, other effects, including catalysis by the ice wall or adsorption of analytes on the wall, have been indicated. These features have attracted the interest of many scientists, especially environmental scientists, because FCSs exist in ice sheets, clouds, and snowpack. − We have found other interesting phenomena that occur in the FCS, including enhancement of crown ether complexation by four orders of magnitude, reduced hydrophobic interactions, and formation of ZnO by simple freezing of a zinc ion solution . Although these behaviors are thought to be related to the properties of water confined in ice, the details have not been elucidated.…”

Section: Introductionmentioning

confidence: 99%

Viscosity of Freeze-Concentrated Solution Confined in Micro/Nanospace Surrounded by Ice

et al. 2017

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An aqueous solution separates into ice and a freeze-concentrated solution (FCS) when frozen at temperatures above the eutectic point. The FCS acts as important reaction media in natural environment and industrial processes. The viscosities of the FCS in frozen glycerol/water solutions are evaluated by two spectrometric methods with different principles: (1) the reaction rate of the diffusion-controlled emission quenching and (2) fluorescence correlation spectroscopy. Thermodynamics indicates that the concentration of glycerol in the FCS is constant at a constant temperature regardless of the glycerol concentration in the original solution before freezing (c gly ini). However, the viscosity of the FCS measured at a given temperature increases with decreasing c gly ini, and this trend becomes more pronounced with decreasing measurement temperature. Further, the viscosity of the FCS in a rapidly frozen solution is higher than that in a slowly frozen solution. These results suggest that the viscosity of the FCS depends on the size of the space in which the FCS is confined and is enhanced in smaller spaces. This result agrees well with several reports of anomalous phenomena in a microspace confined in ice. These phenomena should originate from the fluctuation of the ice/FCS interface, which is macroscopically stable but microscopically dynamic and undergoes continuous freezing and thawing. Thus, the FCS near the interface has ice-like physicochemical properties and structures, giving higher viscosity than the corresponding bulk solution.

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Section: Introductionmentioning

confidence: 99%

Viscosity of Freeze-Concentrated Solution Confined in Micro/Nanospace Surrounded by Ice

et al. 2017

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“…The phase transition in a product from glass to rubber, for instance, induces an increase in molecular mobility of matrix molecules (). Moreover, the molecular mobility of small molecules in food may govern the stability of frozen products in the case of diffusion-controlled reaction ( , ). Thus, gaining access to translational diffusion coefficients may yield very useful information.…”

Section: Introductionmentioning

confidence: 99%

Translational Diffusion Coefficients of Volatile Compounds in Various Aqueous Solutions at Low and Subzero Temperatures

Covarrubias-Cervantes

Champion

Debeaufort

et al. 2005

J. Agric. Food Chem.

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Translational diffusion coefficients (D(12)) of volatile compounds were measured in model media with the profile concentration method. The influence of sample temperature (from 25 to -10 degrees C) was studied on translational diffusion in sucrose or maltodextrin solutions at various concentrations. Results show that diffusivity of volatile compounds in sucrose solutions is controlled by temperature, molecule size, and the viscosity of the liquid phase as expected with the Stokes-Einstein equation; moreover, physicochemical interactions between volatile compounds and the medium are determinant for diffusion estimation. At negative temperature, the winding path induced by an ice crystal content of >70% lowered volatile compound diffusion. On the contrary, no influence on translational diffusion coefficients was observed for lower ice content.

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“…As far as secondary models are concerned, the Arrhenius equation (Equation 2) is mostly applied to describe temperature dependence of quality changes of frozen foods [25]. Nonetheless, there have been serious arguments highlighting its restrictions in describing frozen matrix behavior in the temperature range near the glass transition temperature [43][44][45]. In [46,47], the pros and cons of the alternative secondary models often used for frozen foods, namely Arrhenius and WLF, are presented in detail, underlying their cautious applicability at the lower boundary of the temperature range investigated, since their logarithmic functions render them sensitive to rates.…”

Section: Basic Principlesmentioning

confidence: 99%

Holistic Approach to the Uncertainty in Shelf Life Prediction of Frozen Foods at Dynamic Cold Chain Conditions

Giannakourou

Taoukis

2020

Foods

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Systematic kinetic modeling is required to predict frozen systems behavior in cold dynamic conditions. A one-step procedure, where all data are used simultaneously in a non-linear algorithm, is implemented to estimate the kinetic parameters of both primary and secondary models. Compared to the traditional two-step methodology, more precise estimates are obtained, and the calculated parameter uncertainty can be introduced in realistic shelf life predictions, as a tool for cold chain optimization. Additionally, significant variability of the real distribution/storage conditions is recorded, and must be also incorporated in a kinetic prediction scheme. The applicability of the approach is theoretically demonstrated in an analysis of data on frozen green peas Vitamin C content, for the calculation of joint confidence intervals of kinetic parameters. A stochastic algorithm is implemented, through a double Monte Carlo scheme incorporating the temperature variability during distribution, drawn from cold chain databases. Assuming a distribution scenario of 130 days in the cold chain, 93 ± 110 days remaining shelf life was predicted compared to 180 days assumed based on the use by date. Overall, through the theoretical case study investigated, the uncertainty of models’ parameters and cold chain dynamics were incorporated into shelf life assessment, leading to more realistic predictions.

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Modelling the kinetics of enzyme-catalysed reactions in frozen systems: the alkaline phosphatase catalysed hydrolysis of di-sodium-p-nitrophenyl phosphate

Cited by 15 publications

References 31 publications

Viscosity of Freeze-Concentrated Solution Confined in Micro/Nanospace Surrounded by Ice

Viscosity of Freeze-Concentrated Solution Confined in Micro/Nanospace Surrounded by Ice

Translational Diffusion Coefficients of Volatile Compounds in Various Aqueous Solutions at Low and Subzero Temperatures

Holistic Approach to the Uncertainty in Shelf Life Prediction of Frozen Foods at Dynamic Cold Chain Conditions

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