The Experts below are selected from a list of 267 Experts worldwide ranked by ideXlab platform
Greta Adamczyk - One of the best experts on this subject based on the ideXlab platform.
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the effect of the addition of dietary fibers from apple and oat on the rheological and textural properties of waxy potato starch
Polymers, 2020Co-Authors: Greta Adamczyk, Magdalena Krystyjan, Grazyna JaworskaAbstract:The aim of this paper was to investigate the influence of dietary fibers from oat (OF) and apple (AF) (concentration 0.2%) on the pasting properties, rheological (including Thixotropic and anti-Thixotropic) and textural properties of 3% and 4% (w/w) waxy potato starch pastes. The samples were characterized by their pasting characteristics, the hysteresis loop test, and textural properties measured during storage. It was found that the breakdown viscosity values of the blends, including oat fibers, were lower than those of the others (waxy potato starch (WPS), WPS-AF), which suggests that these samples would have higher resistance to retrogradation and therefore would form a more stable paste. The pattern of flow curves showed that the investigated waxy potato starch and starch-fiber pastes were non-Newtonian fluids, thinned by shear. Areas of the hysteresis loops indicated that pastes with fibers had anti-Thixotropic or mixed Thixotropic/anti-Thixotropic character. The greatest areas of the anti-thixotropy hysteresis loops were characteristic for WPS, while its mixtures with AF and OF caused a decrease in the value of these areas. It can indicate that starch-fiber blends were more stable during shearing. Fiber-type and starch concentration strongly affected the textural parameters of the starch-fiber gels.
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Thixotropic properties of waxy potato starch depending on the degree of the granules pasting
Carbohydrate Polymers, 2015Co-Authors: Magdalena Krystyjan, Greta Adamczyk, Marek Sikora, Anna Dobosz, Piotr Tomasik, Wiktor Berski, Marcin łukasiewicz, P IzakAbstract:Abstract This paper presents the rheological instability (thixotropy/antithixotropy) of waxy potato starch (WPS) pastes depending on their concentration (1–5% w/w) and pasting temperature (80, 95 and autoclaved: 121 °C, at 0.1 MPa). The hysteresis loop, apparent viscosity at constant shear rate as well as the in-shear structural recovery tests with and without pre-shearing were applied. The pastes were also characterized by the granularity profile, molecular weight, polydispersity and optical transmittance. Differences in rheological properties of the pastes prepared at 80 and 95 °C as well as autoclaved resulted from degree of granules pasting. At 121 °C dissolution of the granules occurred, while at the lower temperatures only the partial pasting of the granules took place. Pasting temperature of WPS significantly influenced rheological parameters of the resulted pastes which had Thixotropic, antiThixotropic or mixed Thixotropic/antiThixotropic behavior. Autoclaved pastes, regardless their concentration were antiThixotropic as demonstrated by the areas of hysteresis loops derived from the flow curves signalized by the degree of structure recovery (DSR) which exceeded unity. The apparent viscosity of WPS pasted at 121 °C strongly decreased as compared to the samples pasted at lower temperatures. Samples pasted at 80 and 95 °C showed both Thixotropic and antiThixotropic behavior, with a predominance of the latter. The starch concentration played an important role in the formation of the rheological properties of the resulted pastes. Its influence was strongly connected with the degree of the granules pasting, therefore with the temperature of pastes preparation. For the pastes prepared at 80 and 95 °C the values of thixotropy and apparent viscosity increased, while the values of DSR decreased with an increase of concentration. In the autoclaved pastes the antithixotropy, DSR and apparent viscosity increased with increasing starch concentration. It was also found that apart from the concentration and temperature also the shear rate influence the Thixotropic behavior.
Magdalena Krystyjan - One of the best experts on this subject based on the ideXlab platform.
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the effect of the addition of dietary fibers from apple and oat on the rheological and textural properties of waxy potato starch
Polymers, 2020Co-Authors: Greta Adamczyk, Magdalena Krystyjan, Grazyna JaworskaAbstract:The aim of this paper was to investigate the influence of dietary fibers from oat (OF) and apple (AF) (concentration 0.2%) on the pasting properties, rheological (including Thixotropic and anti-Thixotropic) and textural properties of 3% and 4% (w/w) waxy potato starch pastes. The samples were characterized by their pasting characteristics, the hysteresis loop test, and textural properties measured during storage. It was found that the breakdown viscosity values of the blends, including oat fibers, were lower than those of the others (waxy potato starch (WPS), WPS-AF), which suggests that these samples would have higher resistance to retrogradation and therefore would form a more stable paste. The pattern of flow curves showed that the investigated waxy potato starch and starch-fiber pastes were non-Newtonian fluids, thinned by shear. Areas of the hysteresis loops indicated that pastes with fibers had anti-Thixotropic or mixed Thixotropic/anti-Thixotropic character. The greatest areas of the anti-thixotropy hysteresis loops were characteristic for WPS, while its mixtures with AF and OF caused a decrease in the value of these areas. It can indicate that starch-fiber blends were more stable during shearing. Fiber-type and starch concentration strongly affected the textural parameters of the starch-fiber gels.
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Thixotropic properties of waxy potato starch depending on the degree of the granules pasting
Carbohydrate Polymers, 2015Co-Authors: Magdalena Krystyjan, Greta Adamczyk, Marek Sikora, Anna Dobosz, Piotr Tomasik, Wiktor Berski, Marcin łukasiewicz, P IzakAbstract:Abstract This paper presents the rheological instability (thixotropy/antithixotropy) of waxy potato starch (WPS) pastes depending on their concentration (1–5% w/w) and pasting temperature (80, 95 and autoclaved: 121 °C, at 0.1 MPa). The hysteresis loop, apparent viscosity at constant shear rate as well as the in-shear structural recovery tests with and without pre-shearing were applied. The pastes were also characterized by the granularity profile, molecular weight, polydispersity and optical transmittance. Differences in rheological properties of the pastes prepared at 80 and 95 °C as well as autoclaved resulted from degree of granules pasting. At 121 °C dissolution of the granules occurred, while at the lower temperatures only the partial pasting of the granules took place. Pasting temperature of WPS significantly influenced rheological parameters of the resulted pastes which had Thixotropic, antiThixotropic or mixed Thixotropic/antiThixotropic behavior. Autoclaved pastes, regardless their concentration were antiThixotropic as demonstrated by the areas of hysteresis loops derived from the flow curves signalized by the degree of structure recovery (DSR) which exceeded unity. The apparent viscosity of WPS pasted at 121 °C strongly decreased as compared to the samples pasted at lower temperatures. Samples pasted at 80 and 95 °C showed both Thixotropic and antiThixotropic behavior, with a predominance of the latter. The starch concentration played an important role in the formation of the rheological properties of the resulted pastes. Its influence was strongly connected with the degree of the granules pasting, therefore with the temperature of pastes preparation. For the pastes prepared at 80 and 95 °C the values of thixotropy and apparent viscosity increased, while the values of DSR decreased with an increase of concentration. In the autoclaved pastes the antithixotropy, DSR and apparent viscosity increased with increasing starch concentration. It was also found that apart from the concentration and temperature also the shear rate influence the Thixotropic behavior.
Grazyna Jaworska - One of the best experts on this subject based on the ideXlab platform.
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the effect of the addition of dietary fibers from apple and oat on the rheological and textural properties of waxy potato starch
Polymers, 2020Co-Authors: Greta Adamczyk, Magdalena Krystyjan, Grazyna JaworskaAbstract:The aim of this paper was to investigate the influence of dietary fibers from oat (OF) and apple (AF) (concentration 0.2%) on the pasting properties, rheological (including Thixotropic and anti-Thixotropic) and textural properties of 3% and 4% (w/w) waxy potato starch pastes. The samples were characterized by their pasting characteristics, the hysteresis loop test, and textural properties measured during storage. It was found that the breakdown viscosity values of the blends, including oat fibers, were lower than those of the others (waxy potato starch (WPS), WPS-AF), which suggests that these samples would have higher resistance to retrogradation and therefore would form a more stable paste. The pattern of flow curves showed that the investigated waxy potato starch and starch-fiber pastes were non-Newtonian fluids, thinned by shear. Areas of the hysteresis loops indicated that pastes with fibers had anti-Thixotropic or mixed Thixotropic/anti-Thixotropic character. The greatest areas of the anti-thixotropy hysteresis loops were characteristic for WPS, while its mixtures with AF and OF caused a decrease in the value of these areas. It can indicate that starch-fiber blends were more stable during shearing. Fiber-type and starch concentration strongly affected the textural parameters of the starch-fiber gels.
Jose Munoz - One of the best experts on this subject based on the ideXlab platform.
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influence of xanthan gum and locust bean gum upon flow and Thixotropic behaviour of food emulsions containing modified starch
Journal of Food Engineering, 2007Co-Authors: M Dolz, M J Hernandez, Jesus Delegido, M C Alfaro, Jose MunozAbstract:Abstract Low oil content mayonnaises are food emulsions which exhibit shear thinning and Thixotropic behaviour. They include generally modified starch in their formulation. In this work we study the effect of substituting part of this starch with other natural gums, such as xanthan gum or locust bean gum, upon the consistency and stability of the emulsions in relation to stirring. The gels prior to final emulsification have also been analyzed. Steady flow curves of all systems are well described by the Carreau model. The emulsions containing the greatest percentage of gums presented significantly higher viscosity than the reference emulsion and the emulsions containing the synergistic mixtures of xanthan gum and locust bean gum. To analyze the time dependency, Thixotropic loops were performed. Both up curves and down curves fitted the Herschel–Bulkley model. Analysis of the relative Thixotropic areas calculated by integration, showed that starch substitution with gums led to an increase in emulsions thixotropy.
Régine Perzynski - One of the best experts on this subject based on the ideXlab platform.
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dynamic probing of Thixotropic magnetic gels
Journal of Magnetism and Magnetic Materials, 2002Co-Authors: A Ponton, Régine Perzynski, E Hasmonay, Delphine TalbotAbstract:Abstract The sol–gel transition of Thixotropic magnetic gels is studied at macroscopic and mesoscopic scales by rheology and dynamic birefringence. Gelation times are, respectively, determined from small amplitude shear oscillatory measurements in the framework of Winter's model and from relaxation dynamic birefringence. A fractal dimension of the Thixotropic gel, near the sol–gel transition is evaluated from the rheological measurements.
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ph effect on an ionic ferrofluid evidence of a Thixotropic magnetic phase
Journal of Physical Chemistry B, 1999Co-Authors: E Hasmonay, J C Bacri, Régine PerzynskiAbstract:We investigate the stability of aqueous colloidal dispersions of ionic magnetic nanoparticules as a function of pH. The charge of the γ-Fe2O3 particles is modified, and as a consequence, the interparticle interactions may be tuned through pH variations. Scanning the whole pH scale from acidic to alkaline medium, different states are observed for the dispersion: sol, Thixotropic gel, and floc (around the point of zero charge). Using the dynamic magnetooptical properties of the magnetic grains, we locally probe the sols and the Thixotropic gels. A steep increase of the characteristic time of birefringence relaxation, in the sol phase close to pHGel, marks a divergence of the macroscopic viscosity at the gel point, compatible with a percolation theory. A temporal study of the regeneration of shaken gels reveals that, in these Thixotropic systems, the process is dominated by a cluster aggregation on a sample-spanning one, with an energy barrier to overcome, compatible with chemical measurements.
