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.
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 annealing and cryoprotectants on the properties of vacuum-freeze dried starch nanoparticles
- Authors: Shi, Aimin , Wang, Li-Jun , Li, Dong , Adhikari, Benu
- Date: 2012
- Type: Text , Journal article
- Relation: Carbohydrate Polymers Vol. 88, no. 4 (2012), p. 1334-1341
- Full Text: false
- Reviewed:
- Description: Starch nanoparticles prepared through high pressure homogenization and mini-emulsion cross-linking technology were successfully vacuum-freeze dried. Annealing process was introduced in the drying process and the cryoprotectants (lactose and mannitol) were used in the sample matrix. The effect of the annealing and cryoprotectants on the moisture content, glass transition temperature (T-g), amorphous/crystalline nature, particle size, morphology and the redispersibility of these nanoparticles was investigated. The residual moisture content of the nanoparticles was 4-9% (w/w) and it was lower in samples which were unannealed and contained cryoprotectants. Mannitol as cryprotectant resulted into starch nanoparticles with uniform spherical shape. The T-g of these nanoparticles varied from 52 degrees C to 57 degrees C and the difference was due to annealing and cryoprotectants. The annealing process and the presence of cryoprotectant did not hugely affect the X-ray diffraction pattern and FT-IR spectra which revealed the fully cross-linked and amorphous glassy state of starch nanoparticles. (C) 2012 Elsevier Ltd. All rights reserved.
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.
Effects of high-pressure homogenization on the properties of starch-plasticizer dispersions and their films
- Authors: Fu, Z. Q. , Wang, Li J. , Li, Dong , Wei, Q. , Adhikari, Benu
- Date: 2011
- Type: Text , Journal article
- Relation: Carbohydrate Polymers Vol. 86, no. 1 (2011), p. 202-207
- Full Text: false
- Reviewed:
- Description: The properties of starch-plasticizer (glycerol:xylitol = 1:1) dispersions obtained with and without high-pressure homogenization and their corresponding films were investigated. The fully gelatinized dispersions with or without homogenization were subsequently converted into films using solution casting. The apparent viscosity of the dispersions with or without homogenization was determined. The water vapor permeability, opacity, crystalline/amorphous nature, and mechanical properties of these starch-based films were determined. The high-pressure homogenization greatly reduced the apparent viscosity of the dispersions and altered the flow behavior from shear-thinning into Newtonian one. The films obtained from high-pressure homogenized dispersions had better moisture barrier property, better film transparency and higher tensile strength but lower elongation. © 2011 Elsevier Ltd All rights reserved.
Preparation of starch-based nanoparticles through high-pressure homogenization and miniemulsion cross-linking: Influence of various process parameters on particle size and stability
- Authors: Shi, Aimin , Li, Dong , Wang, Li Ming , Li, Bingzheng , Adhikari, Benu
- Date: 2010
- Type: Text , Journal article
- Relation: Carbohydrate Polymers Vol. 83, no. 4 (2010), p. 1604-1610
- Full Text: false
- Reviewed:
- Description: A new and convenient synthetic route using high-pressure homogenization combined with water-in-oil (w/o) miniemulsion cross-linking technique was used to prepare sodium trimetaphosphate (STMP)-cross-linked starch nanoparticles. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) revealed that starch nanoparticles had narrow size distribution, good dispersibility and spherical shape. Effect of process parameters (surfactant content, water/oil ratio, starch concentration, homogenization pressure and cycles) on the starch nanoparticle size in miniemulsion was evaluated. We show that there is an optimal surfactant concentration giving rise to smaller starch nanoparticles and better stability. Apart from the water/oil ratio and starch concentration, the homogenization pressure and cycles (passes) also significantly affect the size of starch nanoparticles (p < 0.05). The stability analysis of starch nanoparticles in water for 2 h to 2 days and in temperature ranges of 25-45 °C showed firm structure and good stability. These nanoparticles are expected to be exploited as drug carriers. © 2010 Elsevier Ltd. All rights reserved.
- Description: 2003008433