Staff Publications

Staff Publications

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    '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.

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    Integrated Product Recovery Will Boost Industrial Cyanobacterial Processes
    Berg, Corjan van den; Eppink, Michel H.M. ; Wijffels, Rene H. - \ 2019
    Trends in Biotechnology 37 (2019)5. - ISSN 0167-7799 - p. 454 - 463.
    cyanobacteria - process integration - product recovery - separation

    Cyanobacteria promise to be an important industrial platform for the production of a variety of biobased products such as fuels, plastics, and isoprenoids. Recent advances in synthetic biology have resulted in various cyanobacterial strain improvements. Nevertheless, these new strains are still hampered by product inhibition, resulting in low volumetric productivities, product concentrations, and yields on light. To circumvent these issues, continuous product recovery will need to be applied, resulting in economically viable industrial processes. Optimal product recovery strategies can be developed by considering biological and separation process constraints as well as photobioreactor design. Integrated product recovery will be indispensable to bring the cyanobacterial cell factory to industrial scale.

    Slimmer omgaan met poep
    Zeeman, Grietje - \ 2016
    new sanitation - water treatment - waste water - urine - recovery - anaerobic treatment - separation
    Electrostatic separation for functional food ingredient production
    Wang, J. - \ 2016
    Wageningen University. Promotor(en): Maarten Schutyser, co-promotor(en): Remko Boom. - Wageningen : Wageningen University - ISBN 9789462576513 - 176
    particles - fractionation - separation - electrostatic separation - sieving - nitrogen - polystyrenes - wheat gluten - arabinoxylans - starch - milling - lupinus - rice bran - food - experiments - deeltjes - fractionering - scheiding - elektrostatische scheiding - zeven (activiteit) - stikstof - polystyrenen - tarwegluten - arabinoxylanen - zetmeel - maling - lupinus - rijstzemelen - voedsel - experimenten

    Summary

    Dry fractionation is a promising alternative to wet extraction processes for production of food ingredients, since it uses hardly any water, consumes less energy and retains the native functionality of the ingredients. It combines milling and dry separation to enrich agro-materials in specific components such as protein. Electrostatic separation recently emerged as a novel dry separation process and it relies on electrostatic forces for separation. Though the potential of electrostatic separation to fractionate agro-materials has been demonstrated, the effectiveness in terms of purity and yield and the influence of process parameters on charging and separation of food ingredients have not yet been systematically studied. Therefore, the objective of this thesis was to gain better understanding of the charging and separation behaviour of model and agro-materials, provide insight in the critical factors for successful electrostatic separation and explore the potential of this separation method to different agro-materials.

    The charging step is critical to the effectiveness of electrostatic separation and is influenced by many factors. Chapter 2 presents characterization of the charging behaviour of single-component model particles in nitrogen gas flowing through aluminium tubes, using a lab-scale electrostatic separator. Polystyrene particles and wheat gluten were used as model particles. Higher gas velocities led to a higher specific charge by increasing the normal component of impact velocity. Smaller particles gained more specific charge than larger ones because of their higher surface to volume ratio and their sensitivity towards gas flow pattern changes. Longer charging tube lengths allowed more contact between the particles and the wall and therefore resulted in higher specific charge. The relative humidity of the nitrogen gas flow within the range 0 – 60% had no influence on the charging behaviour of both model particles.

    Chapter 3 demonstrates the potential of applying electrostatic separation to enrich arabinoxylans from wheat bran with the same lab-scale electrostatic separator. A combination of larger particle size, higher gas velocity and shorter charging tube was preferred for separation, because it sufficiently charged the particles while agglomeration was minimized. Electrostatic separation with the optimum setting achieved a similar enrichment in arabinoxylans (from 23% to 30% dry matter basis) as sieving does. However, the combination of electrostatic separation and sieving further improved the enrichment and resulted in a fraction with an arabinoxylans content of 43% dry matter basis, which is around the maximum achievable purity that can be reached by dry fractionation.

    To allow better defined charging and separation experiments, a bench-scale electrostatic separator was designed and constructed. With this custom-built separator, the charging and separation of model mixtures prepared from wheat gluten and starch were studied in chapter 4. The net charge of gluten-starch mixtures was not simply the sum of the charge of the two individual components, indicating that particle-particle interactions play an important role. We hypothesized that the formation of agglomerates between oppositely charged particles negatively influenced separation, which was supported by the fact that the dispersibility for mixtures of the two components was lower compared to that of individual components. We found that during electrostatic separation of mixtures, it is important to find the optimal condition that provides sufficient charge to charges, but avoids agglomeration between oppositely charged particles. This could be achieved by the combination of lower dosing rate and higher gas flow rate.

    Chapter 5 reports on dry fractionation by combining milling and electrostatic separation with the custom-built bench-scale separator, providing an alternative to wet extraction of protein from lupine seeds. Relatively coarse milling was preferred because it disclosed sufficient protein bodies from the matrix, while avoiding poor dispersibility of the powder due to its very fine particle size. With the optimal settings of single-step electrostatic separation, a fraction with 57.3 g/100 g dry solids could be obtained. The protein content was further improved to 65.0% dry matter basis after two more separation steps, which is 15% higher than obtained by air classification. The yield of the protein enriched fraction was further increased by recycling the fractions from the filter bags, but this was accompanied by a decrease in protein content and vice versa. A significant shift towards better yield and purities was achieved by re-milling the flour that was not collected on the electrodes. A final fraction with a protein content of 65.1% dry matter basis and a yield of 6% was obtained, which recovered 10% of the protein in the original flour.

    Chapter 6 explores the possibility of enriching dietary fibre from defatted rice bran by dry fractionation, where the custom-built bench-scale electrostatic separator was used. All three tested separation routes produced fibre-enriched fractions with similar yield (20 – 21 % of the milled flour) and fibre content (67 – 68 % dry matter basis), which recovered 42 – 48 % of the fibre from the original flour. The enriched fractions obtained by a two-step electrostatic separation process contained more small particles compared to the other two, which resulted in different functional properties. Compared to the total dietary fibre extracted by the enzymatic-gravimetric method, the enriched fractions by dry fractionation had a similar water retention capacity and oil binding capacity. This suggests that the fibre-enriched fractions by dry fractionation can be applied in foods and provide similar technological properties and physiological effects as the wet-extracted dietary fibre does.

    Chapter 7 concludes the thesis with a general discussion on the main findings, based on which two schemes for protein enrichment and fibre enrichment were proposed. Subsequently the challenges to achieve a successful electrostatic separation for agro-material and up-scaling are discussed. Finally, the chapter ends with an outlook on future research.

    This thesis provided insight in the key factors for successful electrostatic separation. It demonstrated the potential of applying this separation method for functional ingredient production from different agro-materials and also gave directions for further improvement and scaling-up.

    Met scheiding minder mestafvoer en lagere kunstmestkosten
    Evers, A.G. ; Galama, P.J. - \ 2016
    V-focus 2016 (2016)1. - ISSN 1574-1575 - p. 38 - 39.
    mestverwerking - kunstmeststoffen - agrarische bedrijfsvoering - scheiding - melkveehouderij - intensieve veehouderij - kosten-batenanalyse - kostenbeheersing - manure treatment - fertilizers - farm management - separation - dairy farming - intensive livestock farming - cost benefit analysis - cost control
    Toepassen van mestscheiding kan bij melkveehouders die veel mest moeten afvoeren een hoger inkomen opleveren. Besparing op kosten voor mestafvoer is mogelijk omdat de dikke fractie meer mineralen bevat dan drijfmest. Ook blijft er meer werkzame stikstof en kali uit dierlijke mest op het bedrijf, zodat minder kunstmestaankoop nodig is. In dit artikel is voor een intensief melkveebedrijf berekend hoeveel bespaard kan worden bij verschillende scheidingsrendementen en prijzen voor mestscheiding en -afzet.
    Fate of pharmaceuticals in full-scale source separated sanitation system
    Butkovskyi, A. ; Hernandez Leal, L. ; Rijnaarts, H.H.M. ; Zeeman, G. - \ 2015
    Water Research 85 (2015). - ISSN 0043-1354 - p. 384 - 392.
    Anaerobic degradation - Black water - Grey water - Micropollutant removal - Pharmaceuticals - UASB reactor

    Removal of 14 pharmaceuticals and 3 of their transformation products was studied in a full-scale source separated sanitation system with separate collection and treatment of black water and grey water. Black water is treated in an up-flow anaerobic sludge blanket (UASB) reactor followed by oxygen-limited autotrophic nitrification-denitrification in a rotating biological contactor and struvite precipitation. Grey water is treated in an aerobic activated sludge process. Concentration of 10 pharmaceuticals and 2 transformation products in black water ranged between low μg/l to low mg/l. Additionally, 5 pharmaceuticals were also present in grey water in low μg/l range. Pharmaceutical influent loads were distributed over two streams, i.e. diclofenac was present for 70% in grey water, while the other compounds were predominantly associated to black water. Removal in the UASB reactor fed with black water exceeded 70% for 9 pharmaceuticals out of the 12 detected, with only two pharmaceuticals removed by sorption to sludge. Ibuprofen and the transformation product of naproxen, desmethylnaproxen, were removed in the rotating biological contactor. In contrast, only paracetamol removal exceeded 90% in the grey water treatment system while removal of other 7 pharmaceuticals was below 40% or even negative. The efficiency of pharmaceutical removal in the source separated sanitation system was compared with removal in the conventional sewage treatment plants. Furthermore, effluent concentrations of black water and grey water treatment systems were compared with predicted no-effect concentrations to assess toxicity of the effluent. Concentrations of diclofenac, ibuprofen and oxazepam in both effluents were higher than predicted no-effect concentrations, indicating the necessity of post-treatment. Ciprofloxacin, metoprolol and propranolol were found in UASB sludge in μg/g range, while pharmaceutical concentrations in struvite did not exceed the detection limits.

    Production of mineral concentrates from animal manure using reverse osmosis : monitoring of pilot plants in 2012-2014
    Hoeksma, P. ; Buisonjé, F.E. de - \ 2015
    Wageningen : Wageningen UR Livestock Research (Livestock Research report 858) - 21
    livestock - animal manures - manure treatment - slurries - reverse osmosis - separation - vee - dierlijke meststoffen - mestverwerking - drijfmest - omgekeerde osmose - scheiding
    From 2009 to 2011 the agricultural, economic and environmental effects of the production and use of mineral concentrates, produced from animal slurry, were studied. Part of the study was the monitoring of the 8 participating full-scale (pilot) plants to assess the chemical composition of the half products and the end products of the process. In 2012 - 2014 the monitoring programme was continued with 9 pilot plants. In this programme additional data from the pilot plants were collected on the chemical composition of the raw slurry and the end products. Samples from these process streams were analysed on dry matter, volatile solids and the main nutrients N, P and K. The raw material of 8 pilot plants was pig slurry only. One plant used effluent from a biogas plant mixed with pig slurry as a feedstock.
    Nascheiden van verpakkingsglas uit gemengd huishoudelijk restafval : rapportage van een technische haalbaarheidsstudie
    Thoden van Velzen, E.U. - \ 2015
    Wageningen : Wageningen UR - Food & Biobased Research - ISBN 9789462575301 - 29
    recycling - afvalbeheer - scheiding - scheidingstechnologie - glas - haalbaarheidsstudies - afvalverwerking - recycling - waste management - separation - separation technology - glass - feasibility studies - waste treatment
    Het recyclingpercentage voor verpakkingsglas is voor 2012 door Nedvang vastgesteld op 71% en voor 2013 op 79%, terwijl de Nederlandse overheid streeft naar een percentage van 90%. [Nedvang 2012 en Nedvang 2013] Ten einde dit percentage te verhogen, is Nedvang begonnen met een publiciteitscampagne “Glas in ‘t Bakkie” en heeft zij opdracht gegeven voor deze verkennende studie naar de mogelijkheden om glas uit huisvuil na te scheiden.
    Complex coacervates and microgels for emulsions : robust, responsive, reversible
    Monteillet, H.J.M. - \ 2015
    Wageningen University. Promotor(en): Frans Leermakers, co-promotor(en): Mieke Kleijn; Joris Sprakel. - Wageningen : Wageningen University - ISBN 9789462574526 - 147
    emulsies - gels - stabilisatie - elektrolyten - scheiding - emulsions - gels - stabilization - electrolytes - separation

    The use of ionic liquids (ILs) as replacement of organic solvents in liquid-liquid extractions has shown great promise due to their low volatility, flammability and toxicity, tunable solvency to a wide variety of extractable compounds and mild- ness to delicate compounds such as biomolecules for pharmaceutical applications. However, the efficiency of extractions using ionic liquids is limited as the inher- ently high viscosity of ILs slows down the mass transfer. Increasing the interfacial area between the immiscible phases is an efficient way to increase the efficiency of liquid extractions; typically done by formulating emulsions, dispersions of fluid droplets suspended in a second immiscible continuous phase. While strategies to formulate stable emulsions from conventional apolar solvents, such as aliphatic or halogenated oils, in water are abundant, the peculiar properties of ionic liquids requires the exploration of new strategies to formulate stable emulsions; for exam- ple, common surfactant stabilization leads to rapid Ostwald ripening due to the inherent water solubility of many ionic liquids. Moreover, while the intended ionic liquid-in-water emulsions must be stable at operating temperatures for prolonged times, it should be possible to break the emulsion on-demand to recover the ex- tracted product. Also, the interfacial layer used for stabilization should not hinder the transfer of the intended product to the droplet phase. To increase the sus- tainability of extraction processes, recovery of both ionic liquid and stabilizer for re-use in a subsequent extraction step is highly desired. Aimed to establish new ways of stabilizing emulsions in general, and ionic liquid emulsions in specific, this thesis describes investigations into two novel stabilizers: interfacial electrostatic complexes and soft colloidal microgels.

    In Part I, we focussed on how oppositely charged polyelectrolytes interact and form complexes across an oil-water interface. In Chapter 2, we demonstrated a new method for emulsion stabilization, in which electrostatic complexes formed across a liquid interface between two polyelectrolytes, one dissolved in the aqueous phase, the other in the oil phase. Using tensiometry we followed the polyelectrolyte adsorption at the oil-water interface; while the presence of either polyelectrolyte alone leads to interfacial depletion, the presence of both species leads to strong adsorption at the interface. This was further confirmed using confocal fluorescence microscopy where the colocalization of both species at the interface was observed; the strong overlap of peak intensities at the interface suggests a strongly intermixed layer. Using this approach, we prepared stable emulsions, which could be reversibly broken and reformed by simple pH and salt triggers. Interestingly, oil-in-water but also water-in-oil emulsions could be produced. This is the first demonstration of using selective associative phase separation to stabilize a segregating system.

    The experimental results triggered questions on the nature of the interfacial layer, which was too thin to be ascertained in detail using microscopy. Therefore,

    we turned to self-consistent field (SCF) modelling to develop a deeper understand- ing of the structure and thermodynamics of this interfacially-templated complex- ation, as presented in Chapter 3. In analogy with our experiments, we use the Scheutjens-Fleer lattice method to consider mixtures of two solvents, an anionic oil- soluble polyelectrolyte, a cationic water-soluble polyelectrolyte, their counterions and additional indifferent monomeric electrolyte. We first considered a two-phase system with only one polyelectrolyte and salt. We found that the polyelectrolyte adsorption depends on its concentration. For polyelectrolyte concentrations lower than the salt concentration, the polyelectrolyte is depleted from the oil-water in- terface while for polyelectrolyte concentrations higher than the salt concentration, the polyelectrolyte adsorbs at this interface. This transition from depletion to ad- sorption originates from a competition between small ion and macroion adsorption, governed by the overall ionic strength. Upon introducing a second polyelectrolyte in the immiscible second solvent, a new phase spontaneously formed at the inter- face between oil and water. Surprisingly, our calculations showed that ion release entropy is not the driving force for complexation, as it often is in bulk complex coacervation; co-assembly is governed by enthalpic contributions. This is due to the solvent-selectivity of the polyelectrolytes in this scenario, which leads to low solvent content in the coacervate layer, hence close approach of the opposite charges resulting in a relatively large Coulombic enthalpy. Finally, we examined systems with asymmetric composition of the two polyelectrolytes within the same theoret- ical approach. This revealed an unusual pseudo-partial wetting scenario, due to interactions occurring at different length scales. When the electrostatic interactions are short ranged, the microscopically thin wetting film transitions to a mesoscopic thin film. However, charges built up on either side of the coacervate layer restrict the growth of the film to macroscopic dimensions. In our experiments we observe that the coacervate layer becomes turbid over time, suggesting structures on op- tical length scales, much larger than the typical dimensions of the polymer coils. This may be explained by the pseudo-partial wetting scenario due to the coexis- tence of a mesoscopic film with interfacial liquid droplets nucleating due to thermal fluctuations.

    In the second part of this thesis, Part II, we studied the adsorption and or- ganization of colloidal microgels at a variety of liquid interfaces. These soft and deformable hydrogel colloids have gained a lot of interest in recent years due to their excellent ability to stabilize emulsions. As a result of their polymeric nature and osmotic equilibrium with the bulk solution, microgels exhibit an interesting duality between colloidal properties and polymeric behaviour. Microscopic research into their interfacial behaviour is often made difficult as they offer little refractive index contrast to the continuous phase and covalent attachment of fluorophores is known

    to drastically alter their interactions. To overcome this problem, in Chapter 4 we introduce composite microgels, in which a solid fluorescent core is embedded in the centre of a soft and tunable hydrogel shell, thereby decoupling the imaging features of these microgels with the tunability of their softness, size, solvent-responsivity and interactions. We surprisingly find that while these microgels adsorb sponta- neously, without any energy barrier which is usual for the Pickering adsorption of micron-sized colloids, their anchoring at the liquid interface is irreversibly strong. Due to the high adsorption energy, saturated interfacial layers of these microgels show mild compression of the particles, increasing their packing density at the cost of elastic deformation. Moreover, we showed that these particles are able to stabilize a wide variety of oil-water interfaces and due to their spontaneous adsorp- tion allow the fabrication of Pickering droplets using microfluidics, which is usually hindered by the adsorption barrier for solid particles.

    In Chapter 5, we arrive at the ultimate aim of this thesis, i.e. to provide proof- of-concept for a fully sustainable extraction process based on IL-in-water emulsions. We first show how microgels are able to create emulsions of a wide variety of ILs in water and prevent their Ostwald ripening, resulting in extended stability at room temperature. Upon heating and applying centrifugal compression, the emulsion can be rapidly broken, with all of the microgels returning the aqueous phase which can then be re-used in a secondary extraction step. Finally, we demonstrated that through the use of a paramagnetic ionic liquid, the concentration and breaking step can be performed without energy input with a simple permanent magnet, rendering the process sustainable from start to end.

    Finally, in Chapter 6, we studied the adsorption and conformation of these composite microgels at solid-liquid interfaces. We first demonstrate how conven- tional sample preparation for studying microgels at solid interfaces, often involving a drying step, induces strong sample artefacts. We therefore developed a method to study the adsorption and conformation of microgels in-situ using liquid-state confocal and atomic force microscopy. Our results showed how the packing density for particle adsorption is governed by particle-particle repulsion, as adsorption en- ergies are typically very high. Using Quantitative Nanomechanical Mapping, the spatially-resolved mechanical analysis of surfaces using atomic force microscopy, we find that the degree of spreading of microgels during adsorption at a solid interface is governed by adsorption energy and particle softness as expected. This leads us to conclude that the unique properties of microgels at interfaces results from a subtle interplay between adsorption energy and internal elasticity.

    Identification of novel isomeric pectic oligosaccharides using hydrophilic interaction chromatography coupled to traveling-wave ion mobility mass spectrometry
    Leijdekkers, A.G.M. ; Huang, J.H. ; Bakx, E.J. ; Gruppen, H. ; Schols, H.A. - \ 2015
    Carbohydrate Research : an international journal 404 (2015). - ISSN 0008-6215 - p. 1 - 8.
    interaction liquid-chromatography - fluorescent labels - galacturonic acid - cell walls - separation
    Separation and characterization of complex mixtures of pectic oligosaccharides still remains challenging and often requires the use of multiple analytical techniques, especially when isomeric structures are present. In this work, it is demonstrated that the coupling of hydrophilic interaction chromatography (HILIC) to traveling-wave ion mobility mass spectrometry (TWIMMS) enabled the simultaneous separation and characterization of complex mixtures of various isomeric pectic oligosaccharides. Labeling of oligosaccharides with 3-aminoquinoline (3-AQ) improved MS-ionization efficiency of the oligosaccharides and reduced the complexity of the product ion mass spectra, without losing resolution of the HILIC separation. In addition, labeling enabled quantification of oligosaccharides on molar basis using in-line fluorescence detection. Isomeric structures were distinguished using TWIMMS. The 3-AQ-HILIC–TWIMMS method was used to characterize a series of isomeric sugar beet rhamnogalacturonan I derived oligosaccharides carrying a glucuronic acid substituent. Thereby, some novel structural features were identified for the first time: glucuronic acid was attached to O-3 or to O-2 of galacturonic acid residues and a single galacturonic acid residue within an oligomer could contain both an acetyl group and a glucuronic acid substituent.
    Pre- and post-treatment enhance the protein enrichment from milling and air classification of legumes
    Pelgrom, P.J.M. ; Wang, J. ; Boom, R.M. ; Schutyser, M.A.I. - \ 2015
    Journal of Food Engineering 155 (2015). - ISSN 0260-8774 - p. 53 - 61.
    seed moisture-content - product characteristics - flour - pea - separation - fractions - starch - extraction - storage - lipids
    Air classification is a milder and more sustainable method to obtain protein-enriched fractions than commonly used wet fractionation. The protein content of air-classified fractions is generally lower than obtained with wet methods, therefore we applied pre- and post-treatments to increase the protein purity. A starch-rich legume, pea, and an oil-rich legume, lupine, were pre-treated by varying the moisture content, defatting, soaking or freezing cycles. Higher moisture contents and defatting of lupine increased the protein purity, but lower moisture contents increased the protein yield. Soaking and freezing cycles lowered the particle density, which impaired the separation. Electrostatic separation is based on electrostatic charging behaviour and was successfully applied to enrich air-classified fractions by separating protein and fibre into oppositely charged fractions. The results showed that pre- and post-treatments yielded protein fractions that are significantly purer than those obtained in single-step milling and air classification.
    Comparison of structured adsorbents for the adsorptive isolation of food ingredients from large streams
    Rodriguez Illera, M. ; Boon, M.A. ; Boom, R.M. ; Janssen, A.E.M. - \ 2015
    Chemical Engineering Research & Design 98 (2015). - ISSN 0263-8762 - p. 240 - 251.
    stationary phases - moment equations - monolithic adsorbents - liquid-chromatography - aspect ratio - performance - separation - media - diffusion - dynamics
    We present guidelines for the configuration of industrial scale chromatographic separation of small molecules. We compared the performance of different axial packed beds, channeled monoliths and a continuous monolith assuming silica as base material. The calculated mass transfer rates were used to calculate the height of a theoretical plate (HETP). The HETP and pressure drop relations as a function of velocity were used to calculate the resultant velocity and packing length for different conditions (efficiency, pressure drop, affinity constant and throughput). The specific productivity of channeled monoliths can be up to 2.5 orders of magnitude higher than that of a packed bed. This implies that at large scales (in which the pressure drops need to be limited, and the flow rate is high), channeled monoliths are preferred since they may reduce the equipment size up to 100 times and the required resin volume up to 1000 times. Accordingly, we demonstrate the potential of channeled monoliths in chromatographic processes but also draw a window pointing out the feasible configurations to use with the highest productivity for a given set of process requirements.
    A process synthesis approach for isolation of isoflavones from okara
    Jankowiak, L. ; Mendez Sevillano, D. ; Boom, R.M. ; Ottens, M. ; Zondervan, E. ; Goot, A.J. van der - \ 2015
    Industrial & Engineering Chemistry Research 54 (2015)2. - ISSN 0888-5885 - p. 691 - 699.
    driven process synthesis - antioxidant activity - food - adsorption - extraction - separation - products - recovery - integration - components
    Owing to the complexity of food matrices, process synthesis methodologies have not been as widely applied in the food industry as in the chemical industry. Here, we describe the application of a process synthesis methodology to design a system to separate valuable components from a byproduct of the soymilk production. The method yielded a number of potential processing pathways and relevant mechanistic questions, which required experimental input. The combination of considering the overall system on the level of general transformations, heuristics, and additional insights through experiments resulted in a simplified conceptual process design for the separation of isoflavones from okara with a globally more sustainable choice. The holistic approach within process design as an implication of the methodology is discussed.
    Consumer-Related Food Waste: Causes and Potential for Action
    Aschemann-Witzel, J. ; Hooge, I.E. de; Amani, P. ; Bech-Larsen, T. ; Oostindjer, M. - \ 2015
    Sustainability 7 (2015). - ISSN 2071-1050 - p. 6457 - 6477.
    climate-change - behavior - consumption - households - separation - emissions - knowledge - attitude - impacts - system
    In the past decade, food waste has received increased attention on both academic and societal levels. As a cause of negative economic, environmental and social effects, food waste is considered to be one of the sustainability issues that needs to be addressed. In developed countries, consumers are one of the biggest sources of food waste. To successfully reduce consumer-related food waste, it is necessary to have a clear understanding of the factors influencing food waste-related consumer perceptions and behaviors. The present paper presents the results of a literature review and expert interviews on factors causing consumer-related food waste in households and supply chains. Results show that consumers’ motivation to avoid food waste, their management skills of food provisioning and food handling and their trade-offs between priorities have an extensive influence on their food waste behaviors. We identify actions that governments, societal stakeholders and retailers can undertake to reduce consumer-related food waste, highlighting that synergistic actions between all parties are most promising. Further research should focus on exploring specific food waste contexts and interactions more in-depth. Experiments and interventions in particular can contribute to a shift from analysis to solutions.
    Functionality-driven fractionation of lupin seeds
    Berghout, J.A.M. - \ 2015
    Wageningen University. Promotor(en): Remko Boom, co-promotor(en): Atze Jan van der Goot. - Wageningen : Wageningen University - ISBN 9789462572287 - 165
    lupinen - eiwitisolaten - fractionering - scheiding - mechanische eigenschappen - voedselproducten - lupins - protein isolates - fractionation - separation - mechanical properties - food products
    Functionality-driven fractionation of lupin seeds

    The growth in the world population requires an increase in the production of protein-rich foods from plant-based materials. Lupin seeds have potential to become a novel plant protein source for food products because they are rich in protein (about 37 wt%) and they can be grown in moderate temperature climates as in north-western Europe. Besides a high protein content, lupin seeds are rich in dietary fibres (soluble and insoluble), contain about 7-10 wt% oil, and are low in starch. To optimally use the proteins present in lupin, a fractionation process has to be developed. For other legumes, refining of protein is usually performed through wet fractionation techniques. However, wet fractionation methods are resource-intensive, as a result of which the potential reduction in environmental impact when using plant-based materials for foods decreases.

    The aim of this thesis is to obtain understanding of the production of functional, protein-rich material from lupin seeds in a more efficient manner. In this thesis, it is shown that focus on functionality rather than purity can lead to simplified fractionation processes, which is a concept referred to as functionality-driven fractionation (Figure 1). The influence of these simplifications on protein functionality and on physical and chemical stability of the protein isolates was explored. Furthermore, we performed a sustainability assessment of fractionation processes, from which we concluded that focus on a dry product with high purity has a large impact on energy use. In case of lupin, avoiding the oil extraction step as well as the drying step could lead to large gains in sustainability.

    Figure 1 Upper scheme: conventional ingredient production and product processing route, focusing on protein and yield. Lower scheme: novel approach, focusing on functionality and sustainability.

    The results presented in this thesis provide steps towards more sustainable production of functional fractions for food applications obtained with simplified fractionation processes. This work provides future perspectives for functionality-driven fractionation processes that may be extended to other legumes and pulses as well. This approach leads to the development of ingredients and fractions of seeds and legumes that can be used for plant-based food products.

    Star+ : monovergisting mest van vleesvarkens
    Kasper, G.J. ; Verdoes, N. ; Classens, P.J.A.M. - \ 2015
    V-focus 12 (2015)1. - ISSN 1574-1575 - p. 29 - 31.
    varkenshouderij - vleesvee - vleesproductie - varkensstallen - innovaties - varkensmest - mestverwerking - scheiding - mestvergisting - biogas - beoordeling - pig farming - beef cattle - meat production - pig housing - innovations - pig manure - manure treatment - separation - manure fermentation - biogas - assessment
    De versgeproduceerde mest en de vermorste snijmais uit de innovatieve Star+- stal zijn onderzocht op samenstelling en gaspotentie. Daarbij lag de nadruk op de werking van de mestbanden, het optimale drogestofgehalte van de ingevoerde mest, de kwaliteit en kwantiteit van het biogas en de stabiliteit van het vergistingsproces.
    Isolation of bovine serum albumin from whey using affinity chromatography
    Besselink, T. ; Janssen, A.E.M. ; Boom, R.M. - \ 2015
    International Dairy Journal 41 (2015). - ISSN 0958-6946 - p. 32 - 37.
    domain antibody fragments - fractionation - lactoferrin - separation
    The adsorption of bovine serum albumin (BSA) to a chromatography resin with immobilised llama antibody fragments as affinity ligands was investigated. The maximum adsorption capacity of the affinity resin was 21.6 mg mL-1 with a Langmuir equilibrium constant of 20.4 mg mg-1. Using packed bed chromatography, BSA was adsorbed from pure BSA solutions. Recovery was achieved by desorption at pH 3. In experiments with initial BSA concentrations of 1 mg mL-1 and 0.1 mg mL-1, BSA could be concentrated to 6.9 and 7.7 mg mL-1, respectively. BSA was also isolated from filtered bovine cheese whey containing less than 0.1 mg mL-1 BSA. The purified BSA was in this case concentrated to 7.4 mg mL-1 BSA. The presence of other components in the feedstock did not alter the adsorption capacity of the affinity resin. The results show that high recovery combined with high purity can be obtained using affinity chromatography.
    Functional analysis of mildly refined fractions from yellow pea
    Pelgrom, P.J.M. ; Boom, R.M. ; Schutyser, M.A.I. - \ 2015
    Food Hydrocolloids 44 (2015). - ISSN 0268-005X - p. 12 - 22.
    differential scanning calorimetry - protein isolate - isoelectric precipitation - starch characteristics - textural properties - air classification - whey-protein - gels - lentil - separation
    Dry fractionation offers an attractive route to sustainably produce protein-enriched plant-based ingredients. For example, fine milling of peas followed by air classification separates starch granules from the protein matrix. Unlike conventional wet isolates, dry-enriched pea fractions consist of a mixture of protein, starch and fibre, but have the advantage that protein retains its native state. In this context, dryenriched pea ingredients were assessed for their functionality in terms of gelatinization and phase behaviour. After suspension in water, starch, protein and fibre separated into distinctive layers. The top layers were concentrated by ultrafiltration into a native protein-rich concentrate with a purity of 67 g protein/100 g dry matter and a protein yield of 63%. Upon heat-induced gelatinization, gel firmness was mainly increased by the presence of starch, while the presence of dispersed components (i.e. protein and/or fibre patches) in the gel weakened its structure. The heating and cooling rates influenced the firmness of the gel prepared from flour. The fine fraction could be gelled by protein crosslinking using transglutaminase. The increased protein gel strength in the presence of dispersed fibre and starch was explained by their water absorption leading to concentration of the protein phase. In conclusion, all pea fractions could be used to prepare firm gels, despite their different compositions, which supports recent insight that development of novel food ingredients should focus on functionality rather than on molecular purity. Finally, the combination of dry and aqueous phase separation is proposed as a more sustainable route compared to conventional wet extraction processes.
    Seawater electrodialysis with preferential removal of divalent ions
    Galama, A.H. ; Daubaras, G. ; Burheim, O.S. ; Rijnaarts, H. ; Post, J.W. - \ 2014
    Journal of Membrane Science 452 (2014). - ISSN 0376-7388 - p. 219 - 228.
    cation-exchange membranes - of-the-art - nanofiltration membranes - diffusion-coefficients - reverse-osmosis - calcium-sulfate - boundary-layer - monovalent - desalination - separation
    In this work desalination of a ternary salt mixture and at North Sea water is studied with a lab scale electrodialysis stack, which was used in a recycling batch mode. During desalination samples were taken and the ionic composition of the dilute stream was determined. The effect of applied current density (10-300 A/m(2)) On this composition was investigated. A clear effect of applied current density was observed. A lower applied current density leads to a more complete reduction in concentration of divalent ions, in an earlier extent of desalination. This influence of the applied current density could be related to the concentration polarization effects that occur in the diffusional boundary layer and are explained with a model based on the Nernst-Planck flux equation. It was found that the lower initial ion concentration of Ca2+, Mg2+ but also of K+ and SO42- compared to respectively Na+ and Cl-, leads to stronger depletion of these ions in the transport layer adjacent the membrane. These boundary layer effects are more pronounced at higher applied current densities, resulting in reduced transport of ions with a low initial concentration. High monovalent over divalent ion ratios can be found at low applied current. (C) 2013 Elsevier By. All rights reserved.
    Lignin pyrolysis for profitable lignocellulosic biorefineries
    Wild, P.J. de; Gosselink, R.J.A. ; Huijgen, W.J.J. - \ 2014
    Biofuels Bioproducts and Biorefining 8 (2014)5. - ISSN 1932-104X - p. 645 - 657.
    wheat-straw - organosolv lignin - biomass - phenols - separation - valorization - pretreatment - hydrolysis - conversion - chemicals
    Bio-based industries (pulp and paper and biorefineries) produce > 50 Mt/yr of lignin that results from fractionation of lignocellulosic biomass. Lignin is world's second biopolymer and a major potential source for production of performance materials and aromatic chemicals. Lignin valorization is a key-issue for enhanced profitability of sustainable bio-based industries. Despite a myriad of potential applications for lignin and decades of research, its heterogeneity and recalcitrance still preclude commercial value-added applications. Most lignin is utilized for heat and power. Unconventional solutions are needed to better exploit lignin's potential. Organosolv lignins are especially suitable as feedstock for high-value chemicals. At ECN, a lignin biorefinery approach (LIBRA) has been developed, involving a dedicated lignin pyrolysis protocol that is robust, continuous, and capable of processing different lignins. Typical product yields are 20% gas, 35% char, and 45% oil. The oil contains approximately 45% oligomeric phenolic substances, 23% monomeric phenols, and 33% water. The future perspective is scale-up of the process to produce larger lignin pyrolysis oil samples for separation, purification, and industrial application tests. Presently, small lignin pyrolysis oil samples are investigated as feedstock for extracting high-value chemicals, as a substitute for phenol in several applications, and as a feedstock for hydrotreating. The biochar is tested as growth enhancer and as substitute for carbon-black in rubber. Regarding the large lignin side streams from (future) bio-based industries, the LIBRA pyrolysis technology has ample potential to increase the profitability of lignocellulosic biorefineries provided that for both the liquid product and the solid char value-added applications are developed.
    Plastic uit het afval
    Bloemhof-Ruwaard, Jacqueline - \ 2014
    plastics - waste management - waste treatment - recycling - separation - bottles
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