Physicochemical analysis of casein solubility in water-ethanol solutions

Mezdour, Samir; Brulé, G.; Korolczuk, J.

doi:10.1051/lait:2006022

Cited by 12 publications

(19 citation statements)

References 60 publications

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“…Additionally, as the relative dielectric constant was lowering by adding ethanol, the pH of the aqueous ethanol was significantly higher when the ethanol concentration was higher (Mezdour et al . ).…”

Section: Resultsmentioning

confidence: 97%

“…Mart ınez et al (2010) reported the formation of small amounts of formic acid and acetic acid in the hydrolysate of orange peel waste by SCWE at 140 2 160C. Additionally, as the relative dielectric constant was lowering by adding ethanol, the pH of the aqueous ethanol was significantly higher when the ethanol concentration was higher (Mezdour et al 2006).…”

Section: Solid Loss Ph and Yieldmentioning

confidence: 99%

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Effect of Ethanol Addition on Subcritical Water Extraction of Pectic Polysaccharides from Passion Fruit Peel

Klinchongkon

Chanthong

Ruchain

et al. 2016

Journal of Food Processing and Preservation

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The effect of ethanol addition (0 − 30% v/v) on subcritical water extraction (SCWE) of pectic polysaccharides from passion fruit peel was investigated. The peel was extracted in a batch‐type reactor at the treatment temperatures range of 100 − 160C. As a result, low molecular weight pectic polysaccharides in a range of 15.4 − 38.5 kDa were obtained. Higher treatment temperatures tended to give higher yields while the addition of ethanol gave adverse effect, except for adding small amount at high temperatures. The maximum yield (12.28% dry matter basis) was obtained from the treatment at 140C using 10% ethanol. The major composition of extracted pectic polysaccharides was galacturonic acid (72.11 − 94.76%). Additionally, this study demonstrated that the addition of ethanol resulted in pectic polysaccharides that possessed higher 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging activity and total phenolic content (TPC). Practical Applications Subcritical water extraction (SCWE) is an environmentally friendly method that can be used for extraction of pectic polysaccharides from passion fruit peel, which is a major waste from juice production. Addition of ethanol was successful to enhance the extractability of some bioactive compounds in the peel and resulted in pectic polysaccharides with higher total phenolic content (TPC) and free radical scavenging activity, which might be useful as functional food ingredients.

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Section: Resultsmentioning

confidence: 97%

Section: Solid Loss Ph and Yieldmentioning

confidence: 99%

Effect of Ethanol Addition on Subcritical Water Extraction of Pectic Polysaccharides from Passion Fruit Peel

Klinchongkon

Chanthong

Ruchain

et al. 2016

Journal of Food Processing and Preservation

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“…A reação de coagulação induzida pelo etanol é um processo de precipitação isoelétrica dependente da quantidade de cargas existentes nas camadas externas das proteínas que compõem as micelas de caseína (Mezdour et al, 2006). A precipitação das micelas de caseína é dependente do perfil de pH, dos componentes iônicos, como metais bivalentes, especialmente íons cálcio que interferem na estabilização estérica do meio, e da constante dielétrica (Tsioulpas et al, 2007).…”

Section: Materiais E Métodosunclassified

Efeito da temperatura das amostras de leite na concentração de cálcio solúvel e de beta-caseína: interferência no teste de estabilidade frente ao etanol

Costa

Brito

Souza

et al. 2014

Arq. Bras. Med. Vet. Zootec.

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Efeito da temperatura das amostras de leite na concentração de cálcio solúvel e de betacaseína: interferência no teste de estabilidade frente ao etanol RESUMOO objetivo deste trabalho foi avaliar a variação do perfil proteico e do cálcio solúvel na coagulação do leite pelo etanol nas temperaturas de 4ºC, 10ºC, 15ºC e 20ºC. Amostras de leite de 61 animais foram avaliadas quanto à estabilidade ao etanol nas concentrações de 66 a 92% (v/v) nas temperaturas de 4ºC, 10ºC, 15ºC e 20ºC. Três amostras, após 24 horas de armazenamento a 4ºC, foram ultracentrifugadas em quadruplicata (40.000 x g) a 4ºC e a 20ºC, respectivamente, por 60 minutos. Em seguida, o sobrenadante foi retirado e submetido à análise do cálcio solúvel pela técnica via úmida (digestão nitroperclórica) e leitura em espectrofotômetro de absorção atômica. O perfil proteico foi analisado pela técnica de eletroforese capilar empregando kit específico para determinação proteica. Os resultados mostraram uma correlação positiva entre o aumento da temperatura das amostras e a estabilidade do leite frente às diferentes concentrações de etanol. A porcentagem de cálcio solúvel no sobrenadante após ultracentrifugação foi maior nas amostras tratadas a 4ºC (P<0,05). As amostras ultracentrifugadas na temperatura de 4ºC apresentaram quantidades superiores de β-caseína no sobrenadante em comparação com as amostras tratadas a 20ºC. O abaixamento da temperatura favoreceu a migração da β-caseína e do cálcio coloidal para a fase solúvel do leite, o que possivelmente favoreceu o aumento da instabilidade das amostras no teste do etanol. Os resultados sugerem que a temperatura ideal para a realização de teste de estabilidade do leite frente ao etanol deveria ser de 21 o C.Palavras-chave: temperatura do leite, etanol, cálcio, β-caseína, eletroforese ABSTRACT

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“…with z being the amount of charged residues and pk a the acid constant (Mezdour et al, 2006). The activity γ was estimated as 1, a simplification that is admissible for dilute systems.…”

Section: Charge Of Used Cnmentioning

confidence: 99%

“…Surface tension was measured by the du Noüy ring method at concentrations between 10 −3 and 10 −7 mol/L as function of time t, until an equilibrium value γ eq ( ) was reached. The γ eq values of dialyzed and nondia- Mezdour et al (2006) by using the amino acid sequence of the named genetic types published by Ng- Kwai-Hang (2004) and the acid and basic dissociation constants published by Walstra (2003).…”

Section: Surface Propertiesmentioning

confidence: 99%

Properties of an αs-casein-rich casein fraction: Influence of dialysis on surface properties, miscibility, and micelle formation

Kessler

Menéndez-Aguirre

Hinrichs

et al. 2013

Journal of Dairy Science

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In this study, the surface tension, miscibility, and particle size distribution of a solution containing an αs-casein (CN)-rich CN fraction (54 wt % αs-CN, 32 wt % β-CN, and 15 wt % κ-CN) were determined at pH 6.6. The nondialyzed CN fraction was compared with a dialyzed one. In the nondialyzed sample, every charge on the protein was compensated by 0.3 charges coming from counterions, whereas in the dialyzed sample, only 0.2 charges could be assigned to each charge on the protein. This relation was determined by calculating the charges at the proteins, taking the measured mineral content into account. The surface tension was measured as a function of the protein concentration by the du Noüy ring method at room temperature. Results indicated alterations in the surface properties after reduction of counterions. The equilibrium surface tension above the critical micelle concentration increased from 40.1×10(-3) to 45×10(-3) N/m, the critical micelle concentration increased from 0.9×10(-4) to 2×10(-3) mol/L, and the minimal area occupied per molecule at the surface increased from 2.4×10(-18) to 4.6×10(-18) m(2). Cloud points were determined by measuring the absorbance of CN solutions as a function of the temperature. The cloud points were found to be concentration dependent and had a minimum at 0.2 wt % at 34°C for nondialyzed CN and at 0.25 wt % at 28°C for dialyzed CN, again demonstrating the influence of counterion reduction. Below the cloud point, a micellar phase was found to exist. The hydrodynamic diameter of the micelles were characterized by dynamic light scattering in both auto- and cross-correlation mode. However, no influence of reduction in counterions could be observed, possibly due to the fact that dynamic light scattering is not a suitable method for this type of system. The presence of self-assembled structures was verified by freeze-fracture electron microscopy. The observed differences between dialyzed and nondialyzed samples were explained by changes in the counterion cloud surrounding the proteins. Consequently, the electrostatic interactions between as well as within the CN are altered by dialysis, which, in turn, affects the behavior at the surface as well as the properties in the solution.

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Physicochemical analysis of casein solubility in water-ethanol solutions

Cited by 12 publications

References 60 publications

Effect of Ethanol Addition on Subcritical Water Extraction of Pectic Polysaccharides from Passion Fruit Peel

Effect of Ethanol Addition on Subcritical Water Extraction of Pectic Polysaccharides from Passion Fruit Peel

Efeito da temperatura das amostras de leite na concentração de cálcio solúvel e de beta-caseína: interferência no teste de estabilidade frente ao etanol

Properties of an αs-casein-rich casein fraction: Influence of dialysis on surface properties, miscibility, and micelle formation

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