The rheological behavior of native and high-pressure homogenized waxy maize starch pastes
- Authors: Wang, Bao , Wang, Lijun , Li, Dong , Wei, Qing , Adhikari, Benu
- Date: 2012
- Type: Text , Journal article
- Relation: Carbohydrate Polymers Vol. 88, no. 2 (2012), p. 481-489
- Full Text: false
- Reviewed:
- Description: Both steady and large amplitude dynamic rheological testes were carried out in hydrothermally gelatinized waxy maize starch (WMS) pastes. The concentration of WMS was maintained at 6.0% (w/w) throughout these tests. The WMS pastes exhibited shear thickening behavior during the first up curve in steady shear tests. The shear thickening behavior was found to be irreversible and could not be retained after equilibrating the pastes beyond 6 h. The change in the shape of Lissajous curves was insignificant during strain sweeps at higher angular frequencies. This arose because of slow response of WMS pastes to oscillatory strain within a period of oscillatory shear, which can be attributed to the domination of rheological properties by amylopectin in continuous phase. High-pressure homogenization (HPH) was found to significantly reduce the apparent viscosity of the WMS pastes. After HPH, the WMS pastes behaved like typical Newtonian fluids. © 2011 Elsevier Ltd. All rights reserved.
Effect of high-pressure homogenization on microstructure and rheological properties of alkali-treated high-amylose maize starch
- Authors: Wang, Bao , Li, Dong , Wang, Li-jun , Liu, Yan-hong , Adhikari, Benu
- Date: 2012
- Type: Text , Journal article
- Relation: Journal of Food Engineering Vol. 113, no. 1 (2012), p. 61-68
- Full Text: false
- Reviewed:
- Description: The effect of high-pressure homogenization (HPH) on the microstructure, rheological properties, paste clarity, as well as gel retrogradation behavior of alkali-gelatinized high-amylose maize starch (HMS) was investigated. The alkali-treated HMS pastes were subjected to HPH at homogenizing pressures of 25, 50, 75, 100, and 125 MPa. After HPH treatment, the uniformity in the microstructure of HMS pastes was greatly increased. At homogenizing pressures greater than 100 MPa, starch ghost particles were found to completely disappear. The apparent viscosity of the HMS pastes was found to decrease significantly due to the application of HPH. The paste clarity of the HMS pastes increased when HPH treatment was applied. After storing at 4 °C for 7 days, HMS pastes homogenized at 50 and 100 MPa displayed weaker viscoelastic behavior than their corresponding unhomogenized pastes. This indicated that HPH treatment is capable of inhibiting starch retrogradation in gels. © 2012 Elsevier B.V. All rights reserved.
The effect of NaCl on the rheological properties of suspension containing spray dried starch nanoparticles
- Authors: Shi, Aimin , Li, Dong , Wang, Li-jun , Adhikari, Benu
- Date: 2012
- Type: Text , Journal article
- Relation: Carbohydrate Polymers Vol. 90, no. 4 (2012), p. 1530-1537
- Full Text: false
- Reviewed:
- Description: The effect of NaCl on the rheological properties of suspensions containing spray dried starch nanoparticles produced through high pressure homogenization and emulsion cross-linking technique was studied. Rheological properties such as continuous shear viscosity, viscoelasticity and creep-recovery were measured. NaCl (5-20%, w/w) was found to lower viscosity quite significantly (p < 0.05), enhance the heat stability and weaken their gelling behavior compared to starch-only suspension. NaCl reduced both the storage and loss moduli of suspension within the frequency range (0.1-10 rads/s) studied. However, NaCl brought higher speed of reduction on the storage modulus than on the loss modulus, which resulted into large increase in loss angle. The creep-recovery behavior of suspension was affected by NaCl and the recovery rate was highest (86%) at 15% NaCl. The Cross, the Power law and the Burger's models followed the experimental viscosity, storage and loss moduli, and creep-recovery data well with R2 > 0.97. © 2012 Elsevier Ltd. All rights reserved.
Suspensions of vacuum-freeze dried starch nanoparticles : Influence of NaCl on their rheological properties
- Authors: Shi, Aimin , Wang, Li-jun , Li, Dong , Adhikari, Benu
- Date: 2013
- Type: Text , Journal article
- Relation: Carbohydrate Polymers Vol. 94, no. 2 (2013), p. 782-790
- Full Text: false
- Reviewed:
- Description: The effect of addition of NaCl on rheological properties of suspensions containing vacuum freeze dried starch nanoparticles was studied. These starch nanoparticles were produced through high pressure homogenization and emulsion cross-linking technique. Rheological properties such as continuous shear viscosity, storage and loss moduli and creep-recovery were measured. The presence of NaCl at concentration (5-15%, w/v) increased viscosity marginally (p > 0.05) while at 20% (w/v) it significantly (p < 0.05) increased viscosity. The presence of NaCl enhanced heat stability and weakened gelling capacity of suspensions. NaCl concentration below 15% (w/v) marginally (p > 0.05) increased the storage and loss moduli of suspensions. At 20% (w/v), NaCl increased both moduli significantly (p < 0.05) within frequency range tested (0.1-10 rad/s). Creep-recovery behavior was affected by NaCl and recovery rate was the highest (98.6%) at 20% (w/v) NaCl. The Cross, Power Law and Burgers' models followed experimental shear viscosity, storage and loss moduli and creep-recovery data reasonably well ((R
- Description: 2003010855
The effect of addition of flaxseed gum on the rheological behavior of mixed flaxseed gum-casein gels
- Authors: Li, XinYu , Li, Dong , Wang, Li-jun , Wu, Min , Adhikari, Benu
- Date: 2012
- Type: Text , Journal article
- Relation: Carbohydrate Polymers Vol. 88, no. 4 (2012), p. 1214-1220
- Full Text: false
- Reviewed:
- Description: The effect of addition of flaxseed gum on the rheological properties of mixed flaxseed gum-casein gels (flaxseed gum concentration: 0.1-0.5%, w/w and casein concentration: 15-23%, w/w) was studied using both small amplitude oscillatory and steady shear measurements. It was found that the storage (G′) and loss (G″) moduli increased with the increase in the flaxseed gum concentration. Both the experimentally determined G′ and G″ values were fitted well by Power Law model. The addition of flaxseed gum increased the Power Law constants (K′ and K″) at the same time the frequency exponents (n′ and n″) decreased. The G′, G″ of the mixed flaxseed gum-casein gels decreased with increase in temperature. The gelling temperature was found to increase linearly with the increase in flaxseed gum concentration. The apparent viscosities increased with increase in the flaxseed gum and casein concentrations, and were also fitted well by Power Law model. © 2012 Elsevier Ltd. All rights reserved.
Rheology of alkali-activated blended binder mixtures
- Authors: Tekle, Biruk , Hertwig, Ludwig , Holschemacher, Klaus
- Date: 2021
- Type: Text , Journal article
- Relation: Materials Vol. 14, no. 18 (2021), p. 5405
- Full Text: false
- Reviewed:
- Description: Alkali-activated cement (AAC) is an alternative cement that has been increasingly studied over the past decades mainly because of its environmental benefits. However, most studies are on heat-cured AACs and are focused on mechanical properties. There is a lack of research on the fresh properties of ambient-cured AAC systems. This study investigates the rheological properties of ambient-temperature-cured alkali-activated blended binder mixtures activated with sodium silicate and sodium hydroxide solutions. The influence of binder amount, alkaline solid to binder ratio (AS/B), sodium silicate to sodium hydroxide solids ratio (SS/SH), and total water content to total solid (from the binding materials) ratio (TW/TS) on the rheological properties are investigated. The effect of borax as an admixture and silica fume as a replacement for fly ash is also investigated. The results showed that both the yield stress and plastic viscosity are mainly affected by the binder content and TW/TS ratio decreasing with the increase of each parameter. The yield stress increased with the increase of the SS/SH ratio. Borax significantly reduced the yield stress, while silica fume’s effect was dependent on its dosage.