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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    We will mail you new results for this query: keywords==gelatinization
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Influence of lysophosphatidylcholine on the gelation of diluted wheat starch suspensions
Ahmadi-Abhari, S. ; Woortman, A.J.J. ; Hamer, R.J. ; Oudhuis, A.A.C.M. ; Loos, K. - \ 2013
Carbohydrate Polymers 93 (2013)1. - ISSN 0144-8617 - p. 224 - 231.
amylose-lipid complexes - water-content - gelatinization - digestibility - glycerophosphatidylcholine - cultivars - systems - index
Starch is an omnipresent constituent which is used for its nutritional and structuring properties. Recently concerns have been raised since starch is a source of readily available glucose which is tightly correlated with diabetes type II and obesity. For this reason, the possibilities for modulating the digestibility of starch while preserving its functional properties were investigated; therefore the focus of this paper is on starch gelatinization and the effect of lysophosphatidylcholine (LPC) on the structuring properties of wheat starch. The effect of LPC on thermal properties and viscosity behavior of starch suspensions was studied using DSC and RVA, respectively. The influence on granular structure was observed by light microscopy. The RVA profile demonstrated no viscosity increase at high LPC concentrations which proves intact granular structure after gelatinization. LPC in intermediate concentrations resulted in a notable delay of pasting; however the peak and end viscosities were influenced as well. Lower LPC concentrations demonstrated a higher peak viscosity as compared with pure starch suspensions. DSC results imply that inclusion complexes of amylose–LPC might be formed during pasting time. Since the viscosity profiles are changed by LPC addition, swelling power and solubility of starch granules are influenced as well. LPC hinders swelling power and solubility of starch granules which are stimulated by heating.
Molecular and Morphological Aspects of Annealing-Induced Stabilization of Starch Crystallites
Gomand, S.V. ; Lamberts, L. ; Gommes, C.J. ; Visser, R.G.F. ; Delcour, J.A. ; Goderis, B. - \ 2012
Biomacromolecules 13 (2012)5. - ISSN 1525-7797 - p. 1361 - 1370.
x-ray-scattering - intermediate water-content - heat-moisture-treatment - potato starches - physicochemical properties - maize starches - wheat starches - amylose-free - polymers - gelatinization
A unique series of potato (mutant) starches with highly different amylopectin/amylose (AP/AM) ratios was annealed in excess water at stepwise increasing temperatures to increase the starch melting (or gelatinization) temperatures in aqueous suspensions. Small-angle X-ray scattering (SAXS) experiments revealed that the lamellar starch crystals gain stability upon annealing via thickening for high-AM starch, whereas the crystal surface energy decreases for AM-free starch. In starches with intermediate AP/AM ratio, both mechanisms occur, but the surface energy reduction mechanism prevails. Crystal thickening seems to be associated with the cocrystallization of AM with AP, leading to very disordered nanomorphologies for which a new SAXS data interpretation scheme needed to be developed. Annealing affects neither the crystal internal structure nor the spherulitic morphology on a micrometer length scale.
Physicochemical properties of potato and cassava starches and their mutants in relation to their structural properties
Gomand, S.V. ; Lamberts, L. ; Visser, R.G.F. ; Delcour, J.A. - \ 2010
Food Hydrocolloids 24 (2010)4. - ISSN 0268-005X - p. 424 - 433.
rheological properties - cereal starches - rice starches - amylose-free - amylopectin - retrogradation - gelatinization - suspensions - granules - paste
Physicochemical properties [swelling power (SP), pasting behaviour and retrogradation] of five wild type (wt), five amylose free (amf), four high-amylose (ha) potato starches (ps) and one wt and amf cassava starch (cs) were investigated. While swelling of wtps occurred in two phases, amfps showed a very fast swelling and no gel of swollen granules was observed at higher temperatures (>90 °C). Haps underwent only restricted swelling. SP of cassava starches were lower than those of potato starches. Wtps leached mainly amylose (AM) during heating at low temperatures. Molecules of higher molecular weight (MW) leached out at higher temperatures. Longer amylopectin (AP) chains [degree of polymerisation (DP) > 18] inhibited swelling while short chains (DP <14) favoured swelling. Starch pasting behaviour of 5.0 and 8.0% starch suspensions was studied using Rapid Visco Analyser (RVA). For 5.0% suspensions, increased levels of high-MW AP and decreased levels of AM molecules led to higher peak viscosity. Longer AP chains (DP > 18) depressed peak viscosity, while short chains (DP <14) increased peak viscosity for both concentrations. At 8.0%, peak viscosity increased with starch granule size. After 1 day of storage of gelatinised starch suspensions, wtps and especially amfps showed only limited AP retrogradation. In contrast, the high enthalpies of retrograded AP (¿Hretro) and peak and conclusion temperatures of retrogradation (Tp,retro and Tc,retro) of haps suggested partial cocrystallisation between AM and AP. Chains with DP 18–25 seemed to be more liable to AP retrogradation. Wtcs and amfcs did not retrograde at room temperature.
The effect of rice kernel microstructure on cooking behaviour: A combined µ-CT and MRI study
Mohoric, A. ; Vergeldt, F.J. ; Gerkema, E. ; Dalen, G. van; Doel, L.R. van den; Vliet, L.J. van; As, H. van; Duynhoven, J.P.M. van - \ 2009
Food Chemistry 115 (2009)4. - ISSN 0308-8146 - p. 1491 - 1499.
magnetic-resonance - water migration - puffed rice - nmr - grain - gelatinization - starch - profile - flour - model
In order to establish the underlying structure-dependent principles of instant cooking rice, a detailed investigation was carried out on rice kernels that were processed in eight different manners. Milling, parboiling, wet-processing and extrusion were applied, with and without a subsequent puffing treatment. The mesostructure of the rice kernels was examined by DSC and XRD, and the microstructure by µ-CT. Hydration behaviour during cooking was studied by MRI in a real-time manner. Based on simple descriptive models, three different classes of cooking behaviour can be discerned. The water ingress profiles during cooking of these three classes matched well with simulations from a model that was based on water demand of the starch mass and the porous microstructure of the kernels. Thus a clear correlation between meso/microstructure of a rice kernel and the cooking behaviour has been established
On the applicability of Flory-Huggins theory to ternary starch-water-solute systems
Habeych Narvaez, E.A. ; Guo, X. ; Soest, J.J.G. van; Goot, A.J. van der; Boom, R.M. - \ 2009
Carbohydrate Polymers 77 (2009)4. - ISSN 0144-8617 - p. 703 - 712.
differential scanning calorimetry - crystalline polymorph - thermoplastic starch - solvent interactions - phase-transitions - potato starch - wheat-starch - dry starch - gelatinization - glycerol
The effects of glucose and glycerol on gelatinization of highly concentrated starch mixtures were investigated with wide-angle X-ray scattering and differential scanning calorimetry. The gelatinization/melting of starch was found to be a two step process. In the first step the granule swells at low temperatures (i.e., 30¿50 °C), which is followed by a solvent¿temperature cooperative step that induces loss of crystallinity. The results were interpreted with an extended form of the adapted Flory equation. The values of the model parameters (, ¿Hu, ¿12, ¿13, and ¿23) obtained were similar to the values reported in the literature. Ternary phase diagrams were constructed with melting lines representing fully gelatinized starch. The crystalline region of starch with glucose was larger than with glycerol. This could be understood from the differences in ¿13 (solute¿solvent interaction). The extended form of Flory¿Huggins model somewhat under predicts the experimental values of the gelatinization process. Comparing the Flory¿Huggins model with experiments led to the conclusion that Flory equation is a useful tool to interpret and predict the gelatinization and melting behaviour of ternary starch-based systems. But the experiments are complex, the systems are often not in true equilibrium and other disturbing effects are easily encountered. Therefore one should be cautious in the translation of experimental results to the thermodynamics of gelatinization in multicomponent systems
Crystallinity changes in wheat starch during the bread-making process: starch crystallinity in the bread crust
Primo-Martin, C. ; Nieuwenhuijzen, N.H. van; Hamer, R.J. ; Vliet, T. van - \ 2007
Journal of Cereal Science 45 (2007)2. - ISSN 0733-5210 - p. 219 - 226.
heat-moisture treatment - mas nmr-spectroscopy - c-13 cp/mas nmr - phase-transitions - water-system - amylose - gelatinization - amylopectin - polymorphs - potato
The crystallinity of starch in crispy bread crust was quantified using several different techniques. Confocal scanning laser microscopy (CSLM) demonstrated the presence of granular starch in the crust and remnants of granules when moving towards the crumb. Differential scanning calorimetry (DSC) showed an endothermic transition at 70 degrees C associated with the melting of crystalline amylopectin. The relative starch crystallinity, as determined by X-ray and DSC, from different types of breads was found to lie between 36% and 41 % (X-ray) and between 32% and 43 % (DSC) for fresh bread crust. Storage of breads in a closed box (22 degrees C) for up to 20 days showed an increase in crust crystallinity due to amylopectin retrogradation both by X-ray and DSC. However, DSC thermograms of 1-day old bread crust showed no amylopectin retrogradation and after 2 days storage, antylopectin retrogradation in the crust was hardly detectable. C-13 CP MAS NMR was used to characterize the physical state of starch in flour and bread crumb and crust. The intensity of the peaks showed a dependence on the degree of starch gelatinization. Comparison of the results for two different types of bread showed that the baking process influenced the extent of starch crystallinity in the bread crust. Antylopectin retrogradation, which is the main process responsible for the staling of bread crumb, cannot be responsible for crispness deterioration of the crust as amylopectin retrogradation upon storage of breads could only be measured in the crust after 2 days storage. Under the same conditions loss of bread crust crispness proceeds over shorter times.
Magnetic resonance imaging of single rice kernels during cooking
Mohoric, A. ; Vergeldt, F.J. ; Gerkema, E. ; Jager, P.A. de; Duynhoven, J.P.M. van; Dalen, G. van; As, H. van - \ 2004
Journal of Magnetic Resonance 171 (2004)1. - ISSN 1090-7807 - p. 157 - 162.
water migration - nmr - grain - gelatinization - starch - model
The RARE imaging method was used to monitor the cooking of single rice kernels in real time and with high spatial resolution in three dimensions. The imaging sequence is optimized for rapid acquisition of signals with short relaxation times using centered out RARE. Short scan time and high spatial resolution are critical factors in the investigation of the cooking behavior of rice kernels since time and spatial averaging may lead to erroneous results. The results are confirming the general pattern of moisture ingress that has been suspected from previous (more limited) studies. Water uptake as determined by analysis of the MRI time series recorded during cooking compares well with gravimetric studies. This allows using these real-time MRI data for developing and validating models that describe the effect of kernel microstructure on its cooking behavior. (C) 2004 Elsevier Inc. All rights reserved.
The influence of various small plasticisers and malto-oligosaccharides on the retrogradation of (partly) gelatinised starch
Smits, A.L.M. ; Kruiskamp, P.H. ; Soest, J.J.G. van; Vliegenthart, J.F.G. - \ 2003
Carbohydrate Polymers 51 (2003)4. - ISSN 0144-8617 - p. 417 - 424.
glass-transition - chain-length - amylopectin retrogradation - crystalline-structure - gelatinization - amylose - release - gels - saccharides - stabilities
Ageing of gelatinised and partly gelatinised potato starch and wheat starch were investigated in the presence of plasticisers with increasing size and number of OH groups (ethylene glycol, glycerol, threitol, xylitol, glucose, and for potato starch also maltose). The influences of these plasticisers and of granular remnants (ghosts) on recrystallisation were determined by using X-ray diffraction. Recrystallisation of potato starch samples in the presence of plasticisers resulted in crystallinity indices of 0.5. The largest reduction in potato starch recrystallisation is found for threitol (4 OH) and xylitol (5 OH). In the plasticiser range examined, the crystallisation inducing effect of granular potato starch remnants is reduced better when the plasticiser contains more OH groups. Wheat starch recrystallises to a lesser extent than potato starch, resulting in crystallinity indices of 0.4. The results for wheat starch do not show clear trends for the influences of plasticiser size and of ghosts. The difference in behaviour of the two starches is probably caused by wheat starch having shorter amylopectin chains. Resulting from these shorter amylopectin chains, the remaining structure in wheat starch ghosts may resemble A-type crystallinity, making it more difficult to form B-type crystals. Alternatively, the trends as found for potato starch may occur, but are less manifest for wheat starch, due to the lower total extent of recrystallisation. Solid state CP/MAS NMR spectra of the wheat starch samples containing ethylene glycol were obtained, in order to compare completely and partly gelatinised systems. The spectra were identical, confirming that the ghost structures do not influence wheat starch recrystallisation. Apparently, wheat starch ghosts do not act as nuclei for crystallisation. Similarly, the influence of various malto-oligosaccharides in combination with granular remnants (ghosts) was investigated on wheat starch ageing. Gelatinised and partly gelatinised wheat starch were plasticised with maltose, maltotriose, maltotetraose, maltopentaose or maltohexaose. This resulted in crystallinity indices of 0.2, with the largest reduction in recrystallisation for maltotriose and maltotetraose. No trend was found for the influence of ghosts. The presence of ghosts did not influence the 13C solid state HP/DEC NMR spectra. Less recrystallisation took place than with the previously mentioned smaller plasticisers that resulted in crystallinity indices of 0.4. The finding that maltose was able to reduce retrogradation better than glucose could be of practical importance.
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