Staff Publications

Staff Publications

  • external user (warningwarning)
  • Log in as
  • language uk
  • About

    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

    We have a manual that explains all the features 

Records 1 - 20 / 159

  • help
  • print

    Print search results

  • export

    Export search results

  • alert
    We will mail you new results for this query: q=Padt
Check title to add to marked list
High viscosity industrial chromatography for mild food fractionation
Schultze-Jena, Anton - \ 2019
Wageningen University. Promotor(en): A. van der Padt, co-promotor(en): A.E.M. Janssen; F. Boon. - Wageningen : Wageningen University - ISBN 9789463950305 - 140
Oligosaccharides fractionation cascades with 3 outlet streams
Rizki, Zulhaj ; Janssen, Anja E.M. ; Boom, Remko M. ; Padt, Albert van der - \ 2019
Separation and Purification Technology 221 (2019). - ISSN 1383-5866 - p. 183 - 194.
Membrane cascades - Modelling - Nanofiltration - Oligosaccharides

Fructooligosaccharides (FOS) were fractionated using nanofiltration cascades. Instead of creating one product and a residual stream, we report on configurations that create 3 separate product streams rich in: (1) monosaccharides (DP1), (2) DP3 and (3) DP ≥ 5. We developed a modular system allowing different operating pressures and membrane types at each stage. Two possible alternative configurations were assessed for a 3-stage cascade both experimentally and via simulation. The simulation was performed using a steady state model and was in a good agreement with the experimental data. Using the simulation model, the system was optimized towards 4 and 5 stage cascades. All designs were evaluated based on the purities and yields of 3 components of interest in the corresponding product streams. Selecting the correct set up, the cascade was able to reach maximum purity of monosaccharides to 66 wt% (from 9 wt%), DP3 to 33 wt% (from 24 wt%) and DP ≥ 5 to 54 wt% (from 34 wt%). Increasing the number of stages improved the maximum purities of the 3 fractions. However, a fifth stage did not increase the purification and the best purities were found using 4-stage rather than 5-stage cascades.

Fine ultrafiltration of concentrated oligosaccharide solutions – Hydration and pore size distribution effects
Aguirre Montesdeoca, Victor ; Janssen, Anja E.M. ; Boom, R.M. ; Padt, A. van der - \ 2019
Journal of Membrane Science 580 (2019). - ISSN 0376-7388 - p. 161 - 176.
High concentration - Hydration - Maxwell-Stefan equations - Oligosaccharides - Pore size distribution

The effects of high concentration in the fine ultrafiltration of a solution of oligosaccharides were investigated both experimentally and using a mass transfer model based on the Maxwell-Stefan equations. At high concentrations, negative retentions were found for the smaller sugars, which cannot be ascribed to effects of ionic interaction, membrane adsorption or fouling. Instead, the behaviour could be quantitatively described by incorporating the effects of the thermodynamic non-ideality of the solutions and the effects of the pore size distribution. Experiments were performed to validate the model using as feed an oligosaccharide mixture with a concentration up to a 35% w/w. The model predictions allows the identification of an optimum feed concentration at which the efficiency of the separation is maximized. The results show that the fine ultrafiltration of sugars can be well described and predicted when taking into account the relevant thermodynamic interactions, the membrane pore size distribution and pressure effects.

Modelling ultrafiltration performance by integrating local (critical) fluxes along the membrane length
Aguirre-Montesdeoca, Victor ; Janssen, Anja E.M. ; Padt, A. Van der; Boom, R.M. - \ 2019
Journal of Membrane Science 578 (2019). - ISSN 0376-7388 - p. 111 - 125.
Gel layer - Local critical flux - Maxwell-Stefan - Non-idealities - Protein ultrafiltration

Despite the vast number of studies on the understanding and estimation of the permeate flux in ultrafiltration, most of them base their estimations on either one or another mechanism, without pointing out a clear ‘bridge’ between them. The aim of this paper is to assess these mechanisms on the determination of the permeate flux, using as feed a multicomponent mixture of BSA, NaCl and H 2 O. Maxwell-Stefan Equations expressed as function of the components' volume fractions were used for an easier consideration of the non-idealities of the system. These non-idealities (hydration, adsorption, electrical interactions and volume exclusion) were critical in the local fluxes calculation, for which an increase in the thickness of the boundary layer along the filtration channel was considered. The developed model proved to be suitable for the estimation of fluxes lower than the limiting flux. Since the non-idealities of the system can be calculated along the concentration polarization layer, no extra information on the protein diffusivity was needed. Additionally, the fact that the model includes all the components from the solution offers the possibility of including the rejection of the accompanying ions in the calculations.

Ultrafiltration of non-spherical molecules
Aguirre Montesdeoca, Victor ; Bakker, Jaap ; Boom, R.M. ; Janssen, Anja E.M. ; Padt, A. van der - \ 2019
Journal of Membrane Science 570-571 (2019). - ISSN 0376-7388 - p. 322 - 332.
Capsule-shaped molecules - Elongated molecules - Hydration of sugars - Oligosaccharides - Pore size distribution

Information about the sizes of the solute molecules and membrane pores is needed to estimate solute rejection in filtration processes. Molecules are normally regarded as spheres, and the Stokes radius is commonly used to represent their molecular size. However, many molecules used in food and pharma processes are oligomers or polymers which are strongly elongated; therefore, considering them spherical affects the accuracy of the model predictions. We here adapt the so-called Steric Pore Model to a more realistic representation of the transfer of rigid elongated molecules into and through ultrafiltration membrane pores. To do so, sugars with different degree of polymerization were used as model molecules. They were considered to be capsule-shaped to facilitate their size estimation. In order to represent the system as accurately as possible, the effect of hydration on the sugars size was included, and the membrane pore size distribution was estimated based on rejection data. It was demonstrated that considering these molecules to be capsule-shaped instead of spherical generates better predictions over the entire rejection spectrum using a unique pore size distribution. Additionally, this capsular geometry lets us simplify the calculations, making the estimation of the rejection straightforward.

Membrane filtration of food streams: mechanisms and modelling
Aguirre Montesdeoca, Víctor - \ 2018
Wageningen University. Promotor(en): A. van der Padt; R.M. Boom, co-promotor(en): A.E. M. Janssen. - Wageningen : Wageningen University - ISBN 9789463435093 - 193
Bridging process engineering and supply chain design for agro-food processing chains
Jonkman, Jochem - \ 2018
Wageningen University. Promotor(en): J.M. Bloemhof; A. van der Padt. - Wageningen : Wageningen University - ISBN 9789463433389 - 127
Selection of fractionation pathways and intermediates for mixed consumer products
Castiglioni, Alberto ; Jonkman, Jochem ; Akkerman, Renzo ; Padt, Albert van der - \ 2018
In: Computer Aided Chemical Engineering. - Elsevier B.V. (Computer Aided Chemical Engineering ) - ISBN 9780444642356 - p. 651 - 656.
mild fractionation - optimization - process selection - product selection

Mixed consumers products, such as cosmetics and foods, normally consist of a mixture of intermediates. Most of these intermediates are currently produced by fractionation, a rather complex process where multiple intermediates are obtained from a single raw material, often focused on high purity. These intermediates can subsequently be combined to satisfy demand and quality requirements. The chemical purity of intermediates is, however, not always necessary, and mild fractionation of raw materials is often sufficient. Therefore, we propose an optimization-based decision support framework to select cost-efficient fractionation pathways and intermediates. We illustrate our approach for the processing of lupin seeds and yellow peas, and investigate mild fractionation as a more resource-efficient way of producing intermediates for mixed consumer products. The results show that, if only few intermediates are used, high purity is needed to comply with the quality requirements of a broad range of final applications. If more intermediates can be used, mildly refined intermediates can be selected to cover the demand of a part of the products with resource savings. In our illustrative case, using eight instead of four intermediates leads to water and energy reduction of about 29 % and 28 %, respectively. In general, our results indicate that using fractionation pathways leading to intermediates with lower purity provides opportunities for more resource-efficient production, and similar opportunities are expected to exist in integrated product and process design for other mixed consumer products.

Functionality-driven fractionation the need for mild food processing
Geerts, Marlies E.J. - \ 2018
Wageningen University. Promotor(en): A. van der Padt; A.J. van der Goot. - Wageningen : Wageningen University - ISBN 9789463432504 - 151
Exergetic comparison of three different processing routes for yellow pea (Pisum sativum) : Functionality as a driver in sustainable process design
Geerts, Marlies ; Veghel, Amber van; Zisopoulos, Filippos K. ; Padt, Albert van der; Goot, Atze Jan van der - \ 2018
Journal of Cleaner Production 183 (2018). - ISSN 0959-6526 - p. 979 - 987.
Exergy analysis - Functionality - Mild fractionation - Yellow pea
Today, the environmental performance of food products and food ingredients is mostly evaluated on the basis of mass (MJ/kg). However, food ingredients are generally added to obtain a specific functionality, such as increased viscosity or modification of the texture. The functionality obtained is not always fully correlated with the amount of ingredients added. This can be especially true when ingredients are produced using different processes. We have investigated how the functionality of ingredients can be included in a sustainability analysis. Here, we have combined exergy analysis and functionality to select the most beneficial process route for fractionation of yellow pea flour. We assess the resource use efficiency of three fractionation processes for yellow pea flour: conventional wet fractionation (CWF), dry fractionation (DF), and a mild wet fractionation (MWF). Exergy analysis based on mass showed that DF has the highest exergy efficiency (99%), due to the (almost) complete use of raw materials, followed by the MWF (54%) and CWF (35%). Interestingly, even though DF is identified as the preferred technology on exergy analysis based on mass, DF is not the preferred option when the results are expressed as MJ/functionality. In that case, more DF starch is needed to obtain the desired functionality, resulting in higher exergy consumption for DF. This study shows that mass-based exergy analysis could result in an exergy efficient process route, whereas for functional application in a food product, this process route is not always the most efficient with regard to resource. This outcome demonstrates the need for inclusion of functionality in sustainability analysis.
Aqueous fractionation processes of soy protein for fibrous structure formation
Geerts, Marlies E.J. ; Dekkers, Birgit L. ; Padt, Albert van der; Goot, Atze Jan van der - \ 2018
Innovative Food Science and Emerging Technologies 45 (2018). - ISSN 1466-8564 - p. 313 - 319.
Desired properties of ingredients differ for various applications. Here, we use a reverse engineering approach to obtain soy protein fractions targeted for the application of meat analogs. Aqueous fractionation was used to produce these soy protein fractions, which were structured with simple shear flow deformation while heating. The water holding capacity (WHC), nitrogen solubility index (NSI), enthalpy of transition, and viscoelastic properties were determined. We found that a soy protein fraction/full fat flour blend resulted in distinct fibrous structures but only when the soy protein fraction was toasted at 150 °C. At this optimum toasting temperature (150 °C), the protein fractions had a high WHC, intermediate NSI and its viscoelastic property was characterized as G* between 1 and 10 kPa. These functional properties were shown to be key for fibrous structure formation, whereas, the influence of the state of the proteins was limited. Industrial relevance The market for meat analogs is growing. Nowadays, most of the meat analogs are produced with soy protein concentrates and isolates. These concentrates and isolates are obtained with conventional fractionation processes that involve organic solvents to extract the oil first. As a result, the application of these ingredients is limited, e.g. the product cannot be classified as organic. In this study, we therefore investigated aqueous fractionation of soy to obtain a soy protein fraction with desired functionality that can be used for the application of meat analogs and satisfy the values of consumers.
Modelling concentrated multicomponent mixtures of non-spherical molecules for nanofiltration applications
Aguirre Montesdeoca, V.H. ; Padt, A. van der; Boom, R.M. ; Janssen, A.E.M. - \ 2017
Modelling nanofiltration of food streams
Aguirre Montesdeoca, V.H. ; Padt, A. van der; Boom, R.M. ; Janssen, A.E.M. - \ 2017
Protein nativity explains emulsifying properties of aqueous extracted protein components from yellow pea
Geerts, Marlies E.J. ; Nikiforidis, Constantinos V. ; Goot, Atze Jan van der; Padt, Albert van der - \ 2017
Food Structure 14 (2017). - ISSN 2213-3291 - p. 104 - 111.
Emulsification - Mild fractionation - Protein functionality - Yellow pea

In this paper, the emulsifying properties of a protein-enriched fraction from pea are unravelled. The emulsifying properties of mildly fractionated protein fractions from yellow pea and compared to those of commercial pea protein isolate. The emulsion stability of an oil-in-water emulsions were determined under acidic pH, under acceleration forces and a freeze-thaw treatment. It was found that the emulsions stabilized by the mildly fractionated proteins were less prone to flocculation and coalescence. Those differences were related to the interfacial properties, which indicated that the mildly fractioned proteins were able to form a strong and viscoelastic layer on the interface, providing protection against disruption and high compressive forces. The native state of the mildly fractionated protein was used to explain those results. Denatured protein as obtained after conventional fractionation or after applying an additional heating step resulted in an altered interface characteristics, which could explained increased flocculation and droplet coalescence. Overall, the results indicated the relevance of using mild conditions during fractionation. Mild fractionation, thereby shifting the focus from purity to functionality, could be a route to make novel ingredients, with more natural character in a sustainable manner.

Understanding functional properties of mildly refined starch fractions of yellow pea
Geerts, Marlies E.J. ; Strijbos, Marisa ; Padt, Albert van der; Goot, Atze Jan van der - \ 2017
Journal of Cereal Science 75 (2017). - ISSN 0733-5210 - p. 116 - 123.
A route towards the sustainable production of plant based ingredients is the use of milder conditions during fractionation and reduced consumption of chemicals. As a consequence, it becomes more difficult to obtain chemically pure ingredients, instead enriched fractions will be obtained. This paper describes the properties of mildly refined pea starch fractions in comparison to industrially produced and highly refined pea starch. The functional properties investigated are pasting, gel hardness and syneresis upon freezing. The pasting properties of the mildly refined fraction could be well described considering the water binding properties of the main ingredients, which were starch and fibers. The gel hardness was only slightly affected by the presence of fibers in the mildly refined fraction. The fibers mainly acted as a filler. In addition, the mildly refined starch fraction showed a lower syneresis upon freezing, which can be considered as an advantage. The mildly refined starch fraction, and the presence of fibers have slightly different properties compared to highly refined starch. Whether these small differences are advantageous depends on the functionality requested.
Mildly refined fractions of yellow peas show rich behaviour in thickened oil-in-water emulsions
Geerts, Marlies E.J. ; Mienis, Esther ; Nikiforidis, Constantinos V. ; Padt, Albert van der; Goot, Atze Jan van der - \ 2017
Innovative Food Science and Emerging Technologies 41 (2017). - ISSN 1466-8564 - p. 251 - 258.

Conventional fractionation processes aim at high ingredient purity, leading to large water, chemicals and energy consumption. However, as most food product consist of mixtures of ingredients, it is questionable if this high purity is always be necessary. Mild fractionation makes use of the natural organization of the main components present. In this paper, those components are detached through milling, soaking in water and subsequently using centrifugation forces. Two fractions, soluble protein fraction (SPF) and starch fraction (SF), were studied in a thickened oil-in-water emulsion. The soluble pea protein fraction could be used to make a good emulsion, which remained stable upon environmental stresses (e.g. heating and freezing). Furthermore, the viscosity of the mildly refined fractions indicated a cooperative effect between the protein network and the starch gelation. These results indicate that the mild fractionated complexes have promising features and can become an attractive alternative for conventional ingredients. Industrial relevance In this manuscript we aim at understanding the functional properties from fractions that are obtained via mild fractionation concepts. While most focus is now on understanding properties of well-defined, pure ingredients, modern trends, such as increased sustainability and health, point in the direction of less or milder fractionation of plant materials. In this paper, we show that less refined fractions can give rise to interesting properties and can be used to provide functionality now provided by pure ingredients. Overall, this novel approach on the fractionation of ingredients gives a new prospective on prerequisite ingredients must comply.

The counterintuitive role of extra-column volume in the determination of column efficiency and scaling of chromatographic processes
Schultze-Jena, A. ; Boon, M.A. ; Bussmann, P.J.Th. ; Janssen, A.E.M. ; Padt, A. van der - \ 2017
Journal of Chromatography. A, Including electrophoresis and other separation methods 1493 (2017). - ISSN 0021-9673 - p. 49 - 56.
Dead volume - Extra-column contribution - Industrial chromatography - Separation performance

In industrial liquid separation processes chromatography often has a key function in the optimization of yield and purity. For the design of an industrial system, chromatographic processes are generally simulated using mathematical models, tested and optimized at laboratory level, and then scaled up to pilot and subsequently industrial scale. To describe the system, experimental data and model data need to be fitted and extra column contribution must be determined. This paper describes the influence of extra-column volume on overall separation efficiency for lab scale and its impact on the design of large scale systems.Measurement of extra-column contribution was investigated in terms of mean retention time and variance using two different methods the commonly used zero dead volume connector and as an alternative the zero length column. Further a technique is presented to estimate extra-column contribution to band broadening for different injection volumes, velocities, and tracers based on representative measurements.When scaling up, often contribution of extra-column volume from laboratory equipment is neglected assuming to be on the safe side, however column efficiency is often lower than efficiency measured for the entire chromatographic system. Relation between system efficiency and column efficiency was investigated using laboratory data and the lumped kinetic model. Depending on the ratio of extra-column volume to retention volume in the system, deduced column efficiency was up to 20% smaller than overall system efficiency. This ratio revealed the misleading nature of the term efficiency loss, when describing influence of extra-column volume on column efficiency. A scheme, which relates the relative variance of the system to the relative extra-column volume, provided an assessment of under- or overestimation of column efficiency. In this article it is shown how scaling up a system based on laboratory data, where extra-column volume contribution is not accounted for, may severely overestimate column efficiency. This overestimation results in underestimated column dimensions at pilot and industrial scale, and hence underperformance of the industrial system.

Dynamic modeling of ultrafiltration membranes for whey separation processes
Saltık, M.B. ; Özkan, Leyla ; Jacobs, Marc ; Padt, Albert van der - \ 2017
Computers and Chemical Engineering 99 (2017). - ISSN 0098-1354 - p. 280 - 295.
In this paper, we present a control relevant rigorous dynamic model for an ultrafiltration membrane unit in a whey separation process. The model consists of a set of differential algebraic equations and is developed for online model based applications such as model based control and process monitoring. In this model, membrane resistance concept is adjusted to describe the membrane fouling. Based on the observations regarding the permeate flux, we propose a membrane resistance expression consisting of static and dynamic resistances. The empirical expressions for the membrane resistances are identified by solving a parameter estimation problem. The dynamic model is investigated for its predictive capabilities and is further utilised for the study of optimal operation strategies.
Selecting food process designs from a supply chain perspective
Jonkman, Jochem ; Bloemhof-Ruwaard, Jacqueline ; Vorst, Jack G.A.J. van der; Padt, Albert van der - \ 2017
Journal of Food Engineering 195 (2017). - ISSN 0260-8774 - p. 52 - 60.
Facility location - Food industry - Optimization - Process design - Product portfolio - Supply chain configuration

The food industry can convert agro-materials into products using many alternative process designs. To remain competitive, companies have to select the design leading to the best supply chain performance. These designs differ in the technologies used and the product portfolio produced. Additionally, characteristics, such as seasonal production and quality decay of food products, lead to specific requirements regarding processing, transportation and storage. The importance of these characteristics of the food industry on process design selection is investigated using sugar beet processing as an illustrative case. The characteristics are included in a multi-period, multi-product location-allocation model. The model shows that a supply chain perspective leads to changes in process design selection. The design with the best portfolio value and processing costs does not lead to the best supply chain performance. This shows the importance of a chain perspective to avoid sub-optimization in food process design selection.

PSE-NL Mini-Symposium
Padt, A. van der - \ 2016
Product portfolio determines the success of PSE in Agro-Food industry
Check title to add to marked list
<< previous | next >>

Show 20 50 100 records per page

 
Please log in to use this service. Login as Wageningen University & Research user or guest user in upper right hand corner of this page.