Effective Molecular Weight of Aqueous Solutions and Liquid Foods Calculated From the Freezing Point Depression

Chen, C. S.

doi:10.1111/j.1365-2621.1986.tb13853.x

Cited by 61 publications

(43 citation statements)

References 4 publications

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“…The negative value of B indicates that a fraction of solids is behaving as a solvent. Chen [35] indicated that melting/freezing point depression results from the complex interaction between solutes and water and can be expressed by equivalent increases in free water. Thus, the values of B can either be positive or negative depending on the behavior of food constituents.…”

Section: Sugarsmentioning

confidence: 99%

“…The Clausius-Clapeyron equation is applicable to ideal systems, but multicomponent systems are normally nonideal in nature. The Chen equation [35] is an extension of the Clausius-Clapeyron equation and may be used to predict the freezing temperature for non-ideal systems. The Chen equation (6) is expressed as:…”

Section: Characterizing the Effects Of Solids Content On Equilibrium mentioning

confidence: 99%

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A Review of Methods, Data and Applications of State Diagrams of Food Systems

2010

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Understanding of the amorphous glassy state of food systems is often crucial in determining physicochemical characteristics and predicting stability of dehydrated and frozen foods. At the glass transition temperature (T g ) of food components, transformation from the amorphous glassy state to the liquid-like rubbery state occurs. T g and ice-melting temperatures (T m ) of food systems are used to construct their state diagrams, in which the different physical states/phases and state/phase transitions of food components are presented in relation to temperature and concentration. A state diagram may be used to identify the appropriate processing and storage conditions of food systems. An overview of determination methods is carried out for glass transition temperature, ice-melting temperature and conditions of maximum-freeze-concentration (glass transition temperature of maximum-freeze-concentrated solution, T g 0 and onset of ice-melting temperature, T m 0 ) for food systems. The data as T g , T m , T g 0 and T m 0 are necessary for construction of state diagrams of foods. The advantages and limitations of the determination methods are discussed. Combined data for glass transition temperature, ice-melting temperature and conditions of maximum-freeze concentration for selected food systems are presented in this study. The effect of food composition on glass line, freezing/melting curve and maximum-freezeconcentration conditions is evaluated. The significance of the state diagrams in predicting the physical, chemical and microbial stability in foods is briefly examined. Glass transition concept and state diagrams are useful for describing the physical and structural stability of food systems at specific conditions, yet they are not considered as the only determining factors of chemical, biochemical and microbial stability of food systems.

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Section: Sugarsmentioning

confidence: 99%

Section: Characterizing the Effects Of Solids Content On Equilibrium mentioning

confidence: 99%

A Review of Methods, Data and Applications of State Diagrams of Food Systems

2010

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“…Con base en la concentración relativa de los azúcares presentes en el jugo, se calculó el peso molecular efectivo del jugo de uchuva, aplicando la ecuación 3 propuesta por Chen et al (1986):…”

Section: Determinación Experimental Y Predicción Del Punto De Congelaunclassified

Propiedades Físicas del Jugo de Uchuva (Physalis peruviana) Clarificado en Función de la Concentración y la Temperatura

2017

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* Autor a quien debe ser dirigida la correspondenciaRecibido Jun. 22, 2016; Aceptado Ago. 31, 2016; Versión final Oct. 19, 2016, Publicado Feb. 2017 Resumen Se estudió el efecto de la concentración (20 a 50 °Brix) y la temperatura (20 a 50 °C) sobre la densidad y viscosidad del jugo de uchuva (Physalis peruviana) clarificado, empleando un diseño aleatorio con arreglo de dos factores: temperatura con cinco niveles, concentración con siete niveles y tres repeticiones. También se determinó el punto de congelación del jugo de uchuva en función de la concentración. Los valores de densidad y viscosidad del jugo disminuyeron al aumentar temperatura y se incrementaron al aumentar la concentración de sólidos solubles. El efecto de la temperatura sobre la viscosidad del jugo a diferentes concentraciones fue descrito por una relación tipo Arrhenius, encontrándose una energía de activación de flujo en el rango de 7.02 a 17.62 kJ/mol. Los puntos de congelación del jugo se calcularon a partir de las curvas de enfriamiento y los resultados se compararon con los estimados a partir de un modelo aplicable a jugos de frutas, con un error relativo promedio del 6.6%. Palabras claves: uchuva; densidad; viscosidad; energía de activación; punto de congelación Physical Properties of Clarified Cape Gooseberry (Physalis peruviana) Juice as a Function of Concentration and Temperature AbstractThe effect of concentration (20 to 50 °Brix) and temperature (20 to 50 °C) on density and viscosity of clarified cape gooseberry (Physalis peruviana) juice was studied, using a randomized arrangement of two factors: temperature with five levels, concentration with seven levels and three repetitions. In addition, the freezing point of cape gooseberry juice at various concentrations was determined. Density and viscosity values of juice decreased with increasing temperature and increased with increasing concentration of soluble solids. The effect of temperature on viscosity at different concentrations of juice was described by an Arrhenius type relationship while the activation energy of flow was found to be in the range of 7.02 to 17.62 kJ/mol. The freezing points of juice at various concentrations were determined based on the cooling curves. The results were compared with those estimated from a model applicable to fruit juices, with an average relative error of 6.6%.

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“…Several investigations on the A T in food systems have been carried out from the following standpoints: the freezing point and ice fraction of glucose and sucrose in the high concentration range (Pongsawatmanit & Miyawaki, 1993), the relationship between A T and solute composition (sugars and organic acids) in fruit juice systems (Chen et al, 1990), the effective molecular weight of aqueous solutions and liquid foods calculated from AT (Chen, 1986), the AfT of aqueous saccharide solution (sucrose, fructose, Iactose, etc.) and liquid foods (Lerici et al, 1983), the equation ofnon-ideal AfT of a sucrose solution (Fullerton et al, 1992), the equation of the relationship between A T and molal concentration in low ( lO%:~) sucrose concentration (Prentice,1 978), determination of the mean molecular mass of carbowax polyols by AT (Huszur & Pasztor, 1986), the empirical equation for the relationship between A T and concentration (Chen & Nagy, 1987), application of the approximate A T equation of bound water theory to characterize the equilibrium freezing curve (Schwartzberg, 1976;Chen, 1988), and calculation of the coefficient of solute-solvent interaction by the equation for the relationship between Af T and concentration in glycerol solution (Chen, 1987).…”

mentioning

confidence: 99%

Freezing Point Depression of Polyol-Aqueous Solutions in the High Concentration Range.

Uraji

Kohno

Yoshimura

et al. 1996

FSTI

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Freezing points of polyol-aqueous solutions (xylitol, sorbitol, maltitol, Iactitol, and hydrogenated corn syrup) were measured in the high concentration (30-60%) range and compared with those of their corresponding reducing sugar-ones (xylose, glucose and corn syrup). The freezing point depression (AT) of the formers solutions except for the hydrogenated corn syrup tended to be smaller than those of the latter ones. These solutions were not subject to Raoult's law but successfully fitted to Weast's equation for 4(1T in the non-ideal equation. Molecular weights or mean nrolecular weights of saccharides would generally be derived from the slope obtained by Weast's equation and those closely resembled the known chemical molecular ones. Also, 11T was found to be proportional to the reciprocal of the mean dextrose polymerization.

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Effective Molecular Weight of Aqueous Solutions and Liquid Foods Calculated From the Freezing Point Depression

Cited by 61 publications

References 4 publications

A Review of Methods, Data and Applications of State Diagrams of Food Systems

A Review of Methods, Data and Applications of State Diagrams of Food Systems

Propiedades Físicas del Jugo de Uchuva (Physalis peruviana) Clarificado en Función de la Concentración y la Temperatura

Freezing Point Depression of Polyol-Aqueous Solutions in the High Concentration Range.

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