Characterization of starch films containing starch nanoparticles Part 1: Physical and mechanical properties
- Authors: Shi, Aimin , Wang, Li-Jun , Li, Dong , Adhikari, Benu
- Date: 2013
- Type: Text , Journal article
- Relation: Carbohydrate Polymers Vol. 96, no. 2 (2013), p. 593-601
- Full Text: false
- Reviewed:
- Description: We report, for the first time, the preparation method and characteristics of starch films incorporating spray dried and vacuum freeze dried starch nanoparticles. Physical properties of these films such as morphology, crystallinity, water vapor permeability (WVP), opacity, and glass transition temperature (Tg) and mechanical properties (strain versus temperature, strain versus stress, Young's modulus and toughness) were measured. Addition of both starch nanoparticles in starch films increased roughness of surface, lowered degree of crystallinity by 23.5%, WVP by 44% and Tg by 4.3 °C, respectively compared to those of starch-only films. Drying method used in preparation of starch nanoparticles only affected opacity of films. The incorporation of nanoparticles in starch films resulted into denser films due to which the extent of variation of strain with temperature was much lower. The toughness and Young's modulus of films containing both types of starch nanoparticles were lower than those of control films especially at <100 °C. © 2012 Elsevier Ltd. All rights reserved.
- Description: C1
Characterization of starch films containing starch nanoparticles. Part 2: Viscoelasticity and creep properties
- Authors: Shi, Aimin , Wang, Li-jun , Li, Dong , Adhikari, Benu
- Date: 2013
- Type: Text , Journal article
- Relation: Carbohydrate Polymers Vol. 96, no. 2 (2013), p. 602-610
- Full Text: false
- Reviewed:
- Description: Starch films were successfully produced by incorporating spray dried and vacuum-freeze dried starch nanoparticles. The frequency sweep, creep-recovery behavior and time-temperature superposition (TTS) on these films were studied. All these films exhibited dominant elastic behavior (than viscous behavior) over the entire frequency range (0.1-100 rad/s). The incorporation of both types of starch nanoparticles increased the storage and loss modulus, tan δ, creep strain, creep compliance and creep rate at long time frame and reduced the recovery rate of films while the effect of different kinds of starch nanoparticles on these parameters was similar both in magnitude and trend. TTS method was successfully used to predict long time (over 20 days) creep behavior through the master curves. The addition of these nanoparticles could increase the activation energy parameter used in TTS master curves. Power law and Burger's models were capable of fitting storage and loss modulus (R2 > 0.79) and creep data (R2 > 0.96), respectively. © 2012 Elsevier Ltd. All rights reserved.
- Description: C1
Effect of flaxseed meal on the dynamic mechanical properties of starch-based films
- Authors: Wu, Min , Wang, Li-jun , Li, Dong , Mao, Zhihuai , Adhikari, Benu
- Date: 2013
- Type: Text , Journal article
- Relation: Journal of Food Engineering Vol. 118, no. 4 (2013), p. 365-370
- Full Text: false
- Reviewed:
- Description: Starch (S)-flaxseed meal (FM) biofilms were prepared from potato and maize starch by incorporating FM up to 15% (dry solid basis) and using glycerol as plasticizer. The dynamic mechanical properties, tensile properties and water vapor permeability (WVP) of these films were measured. The storage modulus of both the starch (control) and starch-FM films decreased as temperature increased. Tan
- Description: 2003011095
Preparation and characterization of glycerol plasticized (high-amylose) starch-chitosan films
- Authors: Liu, Huihua , Adhikari, Raju , Guo, Qipeng , Adhikari, Benu
- Date: 2013
- Type: Text , Journal article
- Relation: Journal of Food Engineering Vol. 116, no. 2 (2013), p. 588-597
- Full Text: false
- Reviewed:
- Description: The chitosan-starch (high amylose) blend film (1;1), via microfluidization, was prepared by casting with different glycerol concentration (0%, 2.5%, 5% and 10%). The films were characterized for their mechanical, thermal and morphological properties. The addition of glycerol at 5% (w/w) and higher concentrations resulted in decrease in tensile strength, increase in elongation at break due to plasticization. The wellknown antiplasticization was observed in the polymer films with 2.5% of glycerol. The addition of glycerol promoted the interactions among chitosan, starch and glycerol through hydrogen bonding as reflected on the shifting of main peaks of the glycerol-free film to higher wavenumbers as shown by FTIR spectra. The decrease in intensity of glycerol-related peaks in starch-chitosan-glycerol films in both 1H NMR and 13C NMR spectra proved the strong interactions (decrease in glycerol mobility) occurring among starch, chitosan and glycerol in glycerol-plasticized films. © 2012 Elsevier Ltd. All rights reserved.
- Description: C1
The physicochemical characteristics and hydrophobicity of high amylose starch-glycerol films in the presence of three natural waxes
- Authors: Muscat, Delina , Adhikari, Raju , McKnight, Stafford , Guo, Qipeng , Adhikari, Benu
- Date: 2013
- Type: Text , Journal article
- Relation: Journal of Food Engineering Vol. 119, no. 2 (2013), p. 205-219
- Full Text: false
- Reviewed:
- Description: The film forming behaviour and hydrophobicity of high amylose (HA) starch in the presence of three different natural waxes (beeswax, candelilla wax and carnauba wax) were studied in the presence and absence of Tween-80. The HA starch:glycerol (G) ratio was maintained at 80:20 (on dry solid basis) and the concentration of wax was varied from 5% and 10% (w/w). The melted wax samples were homogenized with HAG dispersion with or without Tween-80 and the films were prepared by solution casting. The hydrophobicity and water-barrier properties in these films were determined by using contact angle (CA), water vapour permeability (K
- Description: 2003011133
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 dryer inlet and outlet air temperatures and protectant solids on the survival of Lactococcus lactis during spray drying
- Authors: Ghandi, Amir , Powell, Ian , Chen, Xiao Dong , Adhikari, Benu
- Date: 2012
- Type: Text , Journal article
- Relation: Drying Technology Vol. 30, no. 14 (2012), p. 1649-1657
- Full Text: false
- Reviewed:
- Description: The influence of spray-drying conditions, inlet air temperature (130 degrees C to 200 degrees C), outlet air temperature (38 degrees C to 65 degrees C), drying medium (air and nitrogen) and milk-derived protectants (10%, 15%, and 25% lactose; 5% and 10% sodium caseinate; 10%, 25%, and 35% lactose: sodium caseinate (Lac: NaCas, 3:1)) on the survival of Lactococcus lactis ssp. cremoris was studied using a laboratory-scale spray dryer. An inlet air temperature of 130 degrees C and 65 degrees C as the outlet air temperature maintained high survival of the bacteria without sacrificing low moisture content. Inlet air temperature, previously considered to have no significant effect, was shown to play an important role in the survival of bacteria during spray drying. A mixture of Lac:NaCas (3: 1) showed a better protective effect on the survival of bacteria than lactose and sodium caseinate individually, and this effect increased with increasing amount of protectant. The results were generalized by substituting whey protein isolate for sodium caseinate. Finally, the positive effect of elimination of oxygen was demonstrated both by replacing air with nitrogen and adding ascorbic acid as an oxygen scavenger to improve survival of the bacteria. Adding an oxygen scavenger would be a better candidate for industrial application considering the potential high cost of manufacturing if nitrogen was used as the atomization and/or drying medium.
- Description: C1
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.
Effect of plasticizers on the moisture migration behavior of low-amylose starch films during drying
- Authors: Adhikari, Benu , Chaudhary, Deeptangshu , Clerfeuille, E
- Date: 2010
- Type: Text , Journal article
- Relation: Drying Technology Vol. 28, no. 4 (2010), p. 468-480
- Full Text: false
- Reviewed:
- Description: We report the synergistic and competitive interactions between multiple plasticizers in plasticized low-amylose starch that result in either enhanced or reduced water migration fluxes and effective moisture diffusivities. The starch was plasticized using glycerol and xylitol either individually or in 1:1 combination. The water migration fluxes and moisture diffusivities were higher in xylitol plasticized films compared to the glycerol plasticized ones. For low plasticizer concentrations, the presence of both the plasticizers competitively reduced the effective moisture diffusivities and moisture migration fluxes due to antiplasticization. However, at higher plasticizer contents (at and above 15wt%), the presence of multiple plasticizers enhanced the moisture migration fluxes and effective moisture diffusivities due to synergistic plasticization. The moisture migration fluxes and effective moisture diffusivities exhibited both moisture and plasticizer concentration dependence and the former was found to be stronger than the latter. These findings can be used for designing and controlling the vapor barrier properties of starch-based bioplastics during drying and formulation phase.
- Description: 2003008138
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