Effect of operating temperature on component distribution of West Indian cherry juice in a microfiltration system

Wei, Tsao-Chen; Yu, Zer‐Ran

doi:10.1016/j.lwt.2004.09.002

Cited by 37 publications

(38 citation statements)

References 29 publications

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“…This behavior was similar that observed by Wang [20], and can be explained by solubilization of pectin, reducing it to particle aggregates formation and its surface deposition. According to Sulaiman [18], the linear and branched structure of the pectin molecule allows for mobility and deformation of the chain under the action of an external force, favoring its insertion into the membrane pores.…”

Section: A Fouling Resistancesupporting

confidence: 88%

“…Temperature is favorable for the viscosity and diffusion coefficient pectin, thus high temperature is favorable for water permeation; while the initial pectin concentration interferes on the resistance mechanisms, particularly with the respect to the polarization layer and gelling surface layer. The transmembrane pressure is the driving force, so its increase is favorable to the permeation until the limit, that the equilibrium between the surface renewal and resistive mechanisms.This behavior was similar that observed by Wang [20], and can be explained by solubilization of pectin, reducing it to particle aggregates formation and its surface deposition. According to Sulaiman [18], the linear and branched structure of the pectin molecule allows for mobility and deformation of the chain under the action of an external force, favoring its insertion into the membrane pores.…”

supporting

confidence: 88%

“…The fouling resistance effects were estimated using the fouling resistance model [19], [20]. This model describes the effects that may interfere with the permeate flux as a function of the total resistance R T .…”

Section: Fouling Resistancementioning

confidence: 99%

Section: E Mathematical Models Of the Permeate Fluxmentioning

confidence: 99%

“…In this study, the pore blocking models and the classical filtration theory at constant pressure were used. The classical filtration model adopted [12], [13], [20], expressed as permeate flux, follows (6):where R ME represents the total resistance of the membrane, m PER (t) is the mass of permeate accumulated up to instant t and  is the resistance of the surface cake.The pore blocking models is an empirical model proposed by Hermia [21], and adapted for cross-flow filtration system [22]- [24]. The general pore blocking model can be described by (7):…”

mentioning

confidence: 99%

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Pretreatment of Aqueous Pectin Solution by Cross-Flow Microfiltration: Study on Fouling Mechanism

Gimenes¹,

Silva²,

Hamerski³

et al. 2014

IJCEA

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Abstract-This research was carried out to determine the predominant fouling mechanism during the pretreatment of an aqueous pectin solution by cross-flow microfiltration with membrane with nominal size of 0.44 m, at different values of transmembrane pressure, temperature, and pectin concentration. To evaluate the predominant resistive mechanism was used series resistance and permeate flux model analysis. The rejection coefficient for pectin varied from 93.4 to 97.9%. The maximum flux observed was 238.69 ± 6.48 kg m -2 h -1 at transmembrane pressure of 0.12 MPa, temperature of 50 °C and initial pectin of 1.0 g kg -1 . The dominant restrictive mechanism observed was the cake layer formation, for all assay evaluated.Index Terms-Pectin, microfiltration, permeate flux, fouling. I. INTRODUCTIONPectin is a family of complex polysaccharides constituted of galacturonic acid units linked by  (1→4) glycoside bonds.It also presents esterified regions with methylic groups and branches constituted of neutral sugars. The structure of the lateral chain and the degree of esterification characterize the capacity of gelling, solubilization, and aggregation of pectin in solutions. Due to its gelling characteristic, pectin is a very important raw material in the jelly, sweet, and preserve industries [1]- [3]. In the production of pectin, the most costly step is the purification process, which requires large amounts of ethanol to precipitate pectin from the extraction solution. The ethanol solution is later evaporated by vacuum [4], [5].The porous membrane separation process has been widely used in the food industry, especially in the clarification of juices. The traditional macromolecular fractioning processes that are frequently used in the industry can be optimized with the implementation of membrane separation steps [6]-[8]. According with Moresi [9], the implementation of a microfiltration step before the precipitation with ethanol results in the successful concentration of the extraction solution, reducing the volume of ethanol required to precipitate pectin, and consequently, reducing the energy spent in the evaporation step. Cho et al. [10] incorporated a system of cross-flow microfiltration with a 0.2-m cellulose membrane to a purification step in the extraction of pectin. With the microfiltration system, was achieved a reduction of 75% of the volume of ethanol required.However, the reduction in the permeate flow is a restriction of membrane processes. Pectin is undesirable in the fruit and vegetable juice clarification process, as the typical concentrations of 1 % mass precipitate on the membrane surface as a viscous gel, increasing the resistance to permeation [11]-[13]. The polarization layer is the concentration boundary layer adjacent to the membrane surface, formed in the beginning of process, resulting in a sharp flux decrease, which is stabilized by the renewal surface effect promoted by the crossflow flux [14]. However, a gradual decrease in flux is also observed due to physical and chemical interactions of pect...

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Section: A Fouling Resistancesupporting

confidence: 88%

supporting

confidence: 88%

Section: Fouling Resistancementioning

confidence: 99%