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.

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Production of structured soy-based meat analogues using simple shear and heat in a Couette Cell
Krintiras, G.A. ; Gobel, T.W. ; Goot, A.J. van der; Stefanidis, G.D. - \ 2015
Journal of Food Engineering 160 (2015). - ISSN 0260-8774 - p. 34 - 41.
calcium caseinate dispersions - functional-properties - process parameters - extrusion-cooking - fibrous materials - protein isolate - wheat gluten - microstructure - mixtures - system
A Couette Cell device was employed to provide proof of concept for the production of structured meat analogues by application of simple shear flow and heat to a 31 wt% Soy Protein Isolate (SPI)–Wheat Gluten (WG) dispersion. Three relevant process parameters (temperature, time and rotation rate) were varied over a range of realistic values (90–110 °C, 5–25 min and 5–50 RPM, respectively). Layer- or fibre-structured products with high stress and strain anisotropy indices have been demonstrated. Fibrousness is favoured at temperatures over 90 °C and under 100 °C, whereas the role of process time and rotation rate is not critical. Simultaneous application of simple shear and heat is the key to obtaining structured plant protein-based products. The Couette Cell concept is scalable and can enable continuous operation. On this ground, it appears as a realistic option for production of meat analogues at commercial scale.
Shear structuring as a new method to make anisotropic structures from soy-gluten blends
Grabowska, K.J. ; Tekidou, S. ; Boom, R.M. ; Goot, A.J. van der - \ 2014
Food Research International 64 (2014). - ISSN 0963-9969 - p. 743 - 751.
starch-zein blends - wheat-flour - electron-microscopy - globular-proteins - extrusion-cooking - behavior - microstructure - dispersions - consumption - mechanism
The concept of shear-induced structuring was applied to concentrated blends of soy protein isolate (SPI) and wheat gluten (WG) to create novel semi-solid food textures. Concurrent simple shear deformation and heating (95 °C) of the protein blends generated original structures consisting of fibers or layers. The ratio of SPI to vital WG and the final concentration determined the morphology of the structure. It is hypothesized that the spatial distribution of the SPI-rich phase and the WG-rich phase in a blend was altered by the shear flow. When both phases became aligned horizontally in the shear cell, a fibrous structure was formed; when they became aligned vertically in the shear cell, a layered structure was formed. The structures obtained were analyzed visually and using texture analysis and scanning electron microscopy.
The Maillard reaction and pet food processing: effects on nutritive value and pet health
Rooijen, C. van; Bosch, G. ; Poel, A.F.B. van der; Wierenga, P.A. ; Alexander, L. ; Hendriks, W.H. - \ 2013
Nutrition Research Reviews 26 (2013)2. - ISSN 0954-4224 - p. 130 - 148.
glycation end-products - distillers dried grains - age-related-changes - slope-ratio assay - available lysine - amino-acid - diabetes-mellitus - extrusion-cooking - model systems - growing-pigs
The Maillard reaction, which can occur during heat processing of pet foods or ingredients, is known to reduce the bioavailability of essential amino acids such as lysine due to the formation of early and advanced Maillard reaction products (MRP) that are unavailable for utilisation by the body. Determination of the difference between total and reactive lysine by chemical methods provides an indication of the amount of early MRP present in foods, feeds and ingredients. Previous research reported that the difference between total and reactive lysine in pet foods can be up to 61·8 %, and foods for growing dogs may be at risk of supplying less lysine than the animal may require. The endogenous analogues of advanced MRP, advanced glycation endproducts, have been associated with age-related diseases in humans, such as diabetes and impaired renal function. It is unknown to what extent advanced MRP are present in pet foods, and if dietary MRP can be associated with the development of diseases such as diabetes and impaired renal function in pet animals. Avoidance of ingredients with high levels of MRP and processing conditions known to favour the Maillard reaction may be useful strategies to prevent the formation of MRP in manufactured pet food. Future work should further focus on understanding the effects of ingredient choice and processing conditions on the formation of early and advanced MRP, and possible effects on animal health.
Production of oligosaccharides from extruded wheat and rye biomass using enzymatic treatment
Makaravicius, T. ; Basinskiene, L. ; Juodeikiene, G. ; Gool, M.P. van; Schols, H.A. - \ 2012
Catalysis today 196 (2012)1. - ISSN 0920-5861 - p. 16 - 25.
secale-cereale l. - dietary fiber - nonstarch polysaccharides - extrusion-cooking - physicochemical properties - extractable arabinoxylans - xylo-oligosaccharides - functional-properties - eucalyptus wood - harvest year
Research on prebiotics and other novel healthpromoting food components has been active for over a decade. Arabinoxylan (AX) derived arabinoxylooligosaccharides (AXOS), which may have various chemical structures, depending on the xylan source and the degradation method used, stand increasingly in the spotlight as potential prebiotics. During the past decade, the studies of the possibilities to produce the AXOS by using biocatalytic conversion have received more attention. In addition, there is an interest in the use of novel cereal biomass for the production of AXOS. The aim of this study was to investigate the influence of various commercial enzyme preparations on the degradability of insoluble arabinoxylans in wheat and rye wholemeal treated by extrusion, identify and quantify xylooligosaccharides (XOS) and arabinoxylooligosaccharides (AXOS) in treated media. The enzymatic degradation of rye and wheat cell wall materials was monitored by HPSEC, HPAEC and MALDITOFMS techniques. It was noticed that there is no significant difference between extruded and natural cereals, and type of cereals had not significant influence on XOS and AXOS production. The most effective biocatalysts were hemicellulases expressed in the enzyme preparations from Trichoderma and Aspergillus spp. (Depol 692), Humicola and Bacillus spp. (Ceremix Plus). Degradability of rye and wheat cell wall materials by these enzyme preparations obtained break down percentages of 70–87% and 67–77%, respectively. After enzymatic treatment, only small amounts of xylose, xylobiose, and xylotriose was eluted compare to the amount of more complex oligosaccharides with higher degree of polymerization (DP). The mass spectra of oligosaccharides indicated the presence of a homologous series of pentoses ranging from DP 4 to 15. This indicates that chosen enzyme preparations acted well on wheat and rye biomass, and released quite high amounts of XOS and AXOS.
Improving digestive utilization of fiber-rich feedstuffs in pigs and poultry by processing and enzyme technologies: A review
Vries, S. de; Pustjens, A.M. ; Schols, H.A. ; Hendriks, W.H. ; Gerrits, W.J.J. - \ 2012
Animal Feed Science and Technology 178 (2012)3-4. - ISSN 0377-8401 - p. 123 - 138.
cereal nonstarch polysaccharides - early-weaned piglets - chain fatty-acids - plant-cell walls - broiler-chickens - dietary fiber - nutritive-value - particle-size - gastrointestinal-tract - extrusion-cooking
The effects of processing technologies, whether or not combined with cell wall degrading enzymes, on the physicochemical properties of non-starch polysaccharides (NSP) and the resulting effects on NSP degradation in both pigs and poultry were reviewed. Evaluation of the effects of processing technologies on digestion of NSP is hampered by the potential shift of polysaccharides recovered in the fiber fractions of common, gravimetric, fiber analysis methods. Results from in vivo studies describing effects of processing technologies or enzyme treatments on crude fiber, neutral detergent fiber, or acid detergent fiber digestibility, instead of NSP digestibility, should therefore, be interpreted with care. Detailed information on the composition of the NSP-fraction and digestibility of its components will help to identify and understand modifications that occur during processing. Processes based on mechanical modification of feedstuffs that are commonly used in the feed industry, such as hammer and roller milling increase solubility of the NSP-fraction resulting in a 6–7 percentage unit increase in coefficient of apparent total tract digestibility (CATTD) of the fiber fraction in both pigs and poultry. Dry thermal processes have a minor impact on physicochemical properties of feedstuffs and consequently, the effects on the coefficient of apparent ileal digestibility (CAID) and CATTD of the fiber fractions in pigs and poultry are limited. Hydrothermal processes that include high shear forces such as expander processing and extrusion cooking are more effective and increase solubility but also viscosity. The CATTD of fiber fractions in pigs can be increased on average 3 percentage units by hydrothermal processing of feeds and feed ingredients, although some studies have reported unchanged or even decreased digestibility values. In poultry, CATTD of fiber fractions can be increased 4–16 percentage units by hydrothermal processing. Increased digesta viscosity resulting from technological processing of feed and feed ingredients can be counteracted by the addition of specific enzymes. Enzyme addition to heat processed diets and diets containing heat processed ingredients results in a 3- to 4-fold reduction in viscosity compared with enzyme addition to unprocessed diets, or diets containing unprocessed ingredients. In addition, modifications in cell wall architecture obtained by processing technologies will improve the accessibility of NSP to enzymes. As a result, the effects of enzyme addition on digestibility of the fiber fraction are 1.5–6 times larger, when applied to heat processed diets compared with unprocessed diets.
Formation of oil droplets in plasticized starch matrix in simple shear flow
Emin, M.A. ; Hardt, N.A. ; Goot, A.J. van der; Schuchmann, H.P. - \ 2012
Journal of Food Engineering 112 (2012)3. - ISSN 0260-8774 - p. 200 - 207.
polymer blends - rheological properties - newtonian drop - thermoplastic starch - extrusion-cooking - molecular-weight - sunflower oil - steady shear - corn starch - deformation
This paper describes the effect of simple shear flow on the formation of triglyceride oil droplets in a plasticized starch matrix. An in-house developed shearing device was used that enabled the application of controlled shear flow and rheological characterization of the native maize starch–triglyceride blends at shear stresses of up to 37 kPa. Due to the high viscosity of starch matrix, the viscosity ratio of the continuous starch phase and the dispersed triglyceride phase varied between 10-7 and 10-5. It was possible to create small droplets with a droplet diameter of 2.1 µm using simple shear flow only. An increase in shear rate had no influence on droplet diameter. However, an increase in oil content led to a vast increase in droplet diameter indicating the occurrence of coalescence. The results further show that the maximum stable droplet size in plasticized starch is significantly smaller (up to 100 times) than the predicted values for a Newtonian matrix. The differences of plasticized starch to Newtonian matrices are discussed in detail.
The structural and hydration properties of heat-treated rice studied at multiple lenght scales
Witek, M.M. ; Weglarz, W. ; Jong, L. de; Dalen, G. van; Blonk, J.C.G. ; Heussen, P. ; Velzen, E. van; As, H. van; Duynhoven, J.P.M. van - \ 2010
Food Chemistry 120 (2010)4. - ISSN 0308-8146 - p. 1031 - 1040.
cp-mas nmr - native starch granules - solid-state nmr - molecular mobility - extrusion-cooking - phase-transitions - wheat-starch - puffed rice - water - organization
The impact of heat-treatment on structure and hydration properties of rice was studied at different length scales (µm–nm). Heat-treatment introduced micro- and macro-pores within rice kernels (µCT) and, within intact cell walls, disintegrated starch granules were observed (SEM, CSLM). In native kernels starch predominantly occurred as crystalline A-type starch and, upon heat treatment, amorphous and V-type starch appeared (XRD, 13C CP MAS NMR). Plasticization of amorphous starch by water was more pronounced for heat-treated than for native kernels (13C SPE MAS NMR). Within native kernels, more effective spin diffusion between water and starch chains was present (WISE-Exchange), confirming the inter-helical nanoscale order of amylose helices. Upon heat-treatment, this inter-helical nanoscale order was lost, as well as microscale granular compartmentalisation (TD NMR). These findings explain why, upon heat-treatment, vapour sorption is lower and starch is more prone to gelatinization (DSC).
Influence of process parameters on formation of fibrous materials from dense calcium caseinate dispersions
Manski, J.M. ; Zalm, E.E.J. van der; Goot, A.J. van der; Boom, R.M. - \ 2008
Food Hydrocolloids 22 (2008)4. - ISSN 0268-005X - p. 587 - 600.
extrusion-cooking - mozzarella cheese - simple shear - moisture - microstructure - deformation - particles - proteins - blends - matrix
Concentrated calcium caseinate (Ca-caseinate) in the presence of palm fat forms hierarchical fibrous materials after enzymatic crosslinking under well-defined deformation. The presence of fat induces the protein fibers to be arranged in bundles of 200 fibers, separated by layers that are concentrated in fat. We investigated the effect of shear rate; shear time and protein concentration on the formation of fibrous materials in the two-phase protein¿fat system. The ratio between crosslinking rate and shear rate determined whether a fibrous structure was formed or not, indicating a subtle interplay between material properties and process conditions. Prolonged shear time influenced the transition from fibrous materials into damaged structures accompanied by syneresis. The experimental results are concluded in a generalized diagram, which provides an initial explanation of the structural transitions induced by solidification and shear.
Towards an optimal process for gelatinisation and hydrolysis of highly concentrated starch-water mixtures with alpha-amylase from B. licheniformis
Baks, T. ; Kappen, F.H.J. ; Janssen, A.E.M. ; Boom, R.M. - \ 2008
Journal of Cereal Science 47 (2008)2. - ISSN 0733-5210 - p. 214 - 225.
twin-screw extruder - wheat-starch - enzymatic-hydrolysis - extrusion-cooking - corn starch - sago starch - model - liquefaction - degradation - kinetics
The enzymatic hydrolysis of starch is usually carried out with 30¿35 w/w% starch in water. Higher substrate concentrations (50¿70 w/w%) were reached by using a twin-screw extruder for gelatinisation and for mixing enzyme with gelatinised starch prior to enzymatic hydrolysis in a batch reactor. The aim of this study was to determine which parameters are important for gelatinisation of wheat starch and to investigate the effects of different extrusion conditions on the enzymatic hydrolysis. After extrusion, the degree of gelatinisation was measured. During hydrolysis, the carbohydrate composition, the dextrose equivalent (DE) and the alpha-amylase activity were measured. Gelatinisation measurements showed that mechanical forces lowered the temperature required for complete gelatinisation. During hydrolysis experiments, high DEs were observed even if starch was not completely gelatinised during extrusion. Due to high substrate concentrations, the residual alpha-amylase activity remained high throughout enzymatic hydrolysis, although high temperatures were used. Increased substrate concentrations did not affect the carbohydrate composition of the product. Furthermore, the time required for the batch hydrolysis step could be varied by choosing a different enzyme-to-substrate ratio. This article provides a basis for detailed optimisation of this process to develop an industrial-scale process at high substrate concentrations.
Advances in structure formation of anisotropic protein-rich foods through novel processing concepts
Manski, J.M. ; Goot, A.J. van der; Boom, R.M. - \ 2007
Trends in Food Science and Technology 18 (2007)11. - ISSN 0924-2244 - p. 546 - 557.
induced phase-separation - simple shear-flow - molecular-weight polyethylene - semidilute polymer-solution - nonfat mozzarella cheese - wet spinning technique - extrusion-cooking - wormlike micelles - colloidal dispersions - neutron-scattering
Development of protein-rich food products is currently limited by lack of scientific insights in structuring processes. The application of well-defined flow appears to be a good tool to create novel anisotropic food structures, on one hand, and to improve understanding of the behavior of protein-rich materials during processing, on the other hand. Concentrated protein dispersions show similarities with polymer systems under flow. Also in protein dispersions, the size of structural elements and interactions present account for structural changes due to flow. These insights can form a basis for the design of dedicated food structuring equipment
Formation of fibrous materials from dense caseinate dispersions
Manski, J.M. ; Goot, A.J. van der; Boom, R.M. - \ 2007
Biomacromolecules 8 (2007)4. - ISSN 1525-7797 - p. 1271 - 1279.
non-spinneret formation - wet spinning technique - microbial transglutaminase - functional-properties - sodium caseinate - protein assemblies - extrusion-cooking - light-scattering - shear-flow - water
Application of shear and cross-linking enzyme transglutaminase (Tgase) induced fibrous hierarchical structures in dense (30% w/w) calcium caseinate (Ca-caseinate) dispersions. Using Tgase was essential for the anisotropic structure formation. The fibrous materials showed anisotropy on both micro- and macroscale as determined with scanning electron microscopy (SEM) and mechanical analyses, respectively. SEM revealed protein fibers with a diameter of approximately 100-200 nm; visually, we observed fibers of about 1 mm. Both shear and Tgase affected the reinforcement of the fibers to a large extent, whereas the mechanical properties in the direction perpendicular to the shear flow remained constant. Shearing Ca-caseinate without Tgase yielded a slightly anisotropic layered structure. Both cross-linking in the absence of shear and cross-linking during mixing resulted in gels without alignment. The formation of shear- and enzyme-induced anisotropic structures was explained by aligning of protein aggregates due to shear and concurrent solidification of the aligned protein aggregates.
Starch hydrolysis under low water conditions: a conceptual process design
Veen, M.E. van der; Veelaert, S. ; Goot, A.J. van der; Boom, R.M. - \ 2006
Journal of Food Engineering 75 (2006)2. - ISSN 0260-8774 - p. 178 - 186.
thermostable alpha-amylase - niger glucoamylase-i - twin-screw extruder - enzymatic-hydrolysis - extrusion-cooking - corn starch - reactor - kinetics - glucose - liquefaction
A process concept is presented for the hydrolysis of starch to glucose in highly concentrated systems. Depending on the moisture content, the process consists of two or three stages. The two-stage process comprises combined thermal and enzymatic liquefaction, followed by enzymatic saccharification. The three-stage process starts with shear induced melting of starch, followed by enzymatic liquefaction and saccharification. At a low moisture content, the shear stress needed to completely melt corn starch is so high that significant enzyme inactivation cannot be avoided, which leads to a need for separating starch melting and liquefaction in two separate processing steps. Assuming the use of currently available enzymes, the final product composition was estimated to contain 69-93% glucose, starting with respectively 65% and 35% dry starch. These results showed that the formation of side-products, mainly isomaltose and isomaltotriose, increased with increasing dry matter content. Increasing the dry matter content from 35% to 65% resulted in increasing reactor productivity of 17%, while the amount of water that should be removed from the system was reduced by 87%. (c) 2005 Elsevier Ltd. All rights reserved.
Modeling macromolecular degradation of corn starch in a twin screw extruder
Einde, R.M. van den; Veen, M.E. van der; Bosman, H. ; Goot, A.J. van der; Boom, R.M. - \ 2005
Journal of Food Engineering 66 (2005)2. - ISSN 0260-8774 - p. 147 - 154.
waxy-maize starch - wheat-starch - thermomechanical treatment - extensional viscosity - extrusion-cooking - shear - breakdown - rheometer - flour
Macromolecular degradation of starch in a twin screw extruder was modeled. A shear cell having well-defined flow conditions described earlier was used to measure peak viscosity of corn starch melts at various moisture contents and temperatures. Shear rate and elongation rate distributions in the extruder were estimated from numerical calculations from literature and elongational viscosity was estimated using the Trouton ratio. In this way, stresses in the extruder were calculated and, using relations on maximum stress vs. intrinsic viscosity obtained in earlier work, the expected relative intrinsic viscosity was calculated. The model gave a good prediction of relative intrinsic viscosity after extrusion at various temperatures (97-130 °C), moisture contents (23-45%) and screw speeds (90 or 140 rpm). This suggests that the use of pilot scale equipment having a well-defined flow pattern can be useful for understanding complex processes such as extrusion.
The effect of thermomechanical treatment on starch breakdown and the consequences for process design
Einde, R.M. van den; Bolsius, A. ; Soest, J.J.G. van; Janssen, L.P.B.M. ; Goot, A.J. van der; Boom, R.M. - \ 2004
Carbohydrate Polymers 55 (2004)1. - ISSN 0144-8617 - p. 57 - 63.
single-screw extruder - maize starch - extrusion-cooking - covalent bond - wheat-starch - degradation - depolymerization - time
Macromolecular degradation of starch by heating and shear forces was investigated using a newly developed shear cell. With this equipment, waxy corn starch was subjected to a variety of heat and shear treatments in order to find the key parameter determining the degree of macromolecular degradation. A model based on the maximal shear stress during the treatment gave an improved prediction compared to existing models in literature based on specific mechanical energy input (SME) or shear stress multiplied by time (tau(.)t). It was concluded that molecular weight reduction of starch at the temperatures investigated (85-110degreesC) is a time-independent process, during which the starch molecules are broken down virtually instantaneously by high shear force within time scales investigated. Consequences for design of shear based processes (especially extrusion) are shortly discussed. (C) 2003 Elsevier Ltd. All rights reserved.
Understanding molecular weight reduction of starch during heating-shearing processes
Einde, R.M. van den; Goot, A.J. van der; Boom, R.M. - \ 2003
Journal of Food Science 68 (2003)8. - ISSN 0022-1147 - p. 2396 - 2404.
twin-screw extruder - plasticized wheat-starch - waxy-maize starch - extrusion-cooking - corn meal - in-line - extensional viscosity - functional-properties - rheological behavior - potato starch
Recent understanding of the mechanisms underlying the changes in molecular weight of starch as a function of process parameters during thermomechanical treatment, for example extrusion, holds promise towards more effective optimization of thermomechanical processes according to the desired modification of molecular weight. This paper summarizes recent advances in theoretical understanding and experimental methods. Empirical observations from extruder experiments can be better understood on this basis. The current status in this field has opened up potential for developing new equipment in which the main process parameters, which normally occur simultaneously, can be separated and optimized. This will create a much wider window for product-oriented process design and for new products.
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