Rheological properties of suspensions containing cross-linked starch nanoparticles prepared by spray and vacuum freeze drying methods
- 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. 1732-1738
- Full Text: false
- Reviewed:
- Description: The rheological behavior of suspensions containing vacuum freeze dried and spray dried starch nanoparticles was investigated to explore the effect of these two drying methods in producing starch nanoparticles which were synthesized using high pressure homogenization and mini-emulsion cross-linking technique. Suspensions containing 10% (w/w) spray dried and vacuum freeze dried nanoparticles were prepared. The continuous shear viscosity tests, temperature sweep tests, the frequency sweep and creep-recovery tests were carried out, respectively. The suspensions containing vacuum freeze dried nanoparticles showed higher apparent viscosity within shear rate range (0.1-100 s -1) and temperature range (25-90 °C). The suspensions containing vacuum freeze dried nanoparticles were found to have more shear thinning and less thixotropic behavior compared to those containing spray dried nanoparticles. In addition, the suspensions containing vacuum freeze dried particles had stronger elastic structure. However, the suspensions containing spray dried nanoparticles had more stiffness and greater tendency to recover from the deformation. © 2012 Elsevier Ltd. All rights reserved.
Spray drying of starch submicron particles prepared by high pressure homogenization and mini-emulsion cross-linking
- Authors: Shi, Aimin , Li, Dong , Wang, Li-jun , Zhou, Yuguang , Adhikari, Benu
- Date: 2012
- Type: Text , Journal article
- Relation: Journal of Food Engineering Vol. 113, no. 3 (2012), p. 399-407
- Full Text: false
- Reviewed:
- Description: The suspensions containing starch submicron particles prepared through a novel high pressure homogenization and mini-emulsion cross-linking technology were spray dried to obtain cross-linked starch submicron particles. Dryer inlet temperature and feed flow rate were varied to investigate their effect on moisture content, glass transition temperature (T g), morphology of the starch submicron particles. The residual moisture content of the particles was below 10% (w/w) and particle had collapsed morphology. The T g of these submicron particles varied between 54 and 57°C corresponding to moisture contents of 9.78% and 8.31%, respectively and the cross-linking and the high hydrogen bond density in these submicron particles strongly affected the moisture dependence in their T g. The X-ray diffraction and FT-IR experiments revealed that these starch submicron particles were in amorphous glassy state, fully cross-linked and had very high extent of hydrogen bonding. © 2012 Elsevier Ltd. 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.