scholarly journals Potato Starch Hydrogels Produced by High Hydrostatic Pressure (HHP): A First Approach

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1673 ◽  
Author(s):  
Dominique Larrea-Wachtendorff ◽  
Gipsy Tabilo-Munizaga ◽  
Giovanna Ferrari
Keyword(s):  
Mechanical Properties ◽  
Hydrostatic Pressure ◽  
High Hydrostatic Pressure ◽  
Potato Starch ◽  
Water Concentration ◽  
Medium Size ◽  
Processing Temperature ◽  
Processing Conditions ◽  
Scanning Calorimetry ◽  
Absorption Bands

Starch-based hydrogels have received considerable interest due to their safe nature, biodegradability and biocompatibility. The aim of this study was to verify the possibility of producing natural hydrogels based on potato starch by high hydrostatic pressure (HHP), identifying suitable processing conditions allowing to obtain stable hydrogels, as well as to characterize structural and mechanical properties of these products. Sieved (small size granules and medium size granules) and unsieved potato starch samples were used to prepare aqueous suspensions of different concentrations (10–30% w/w) which were processed at 600 MPa for 15 min at different temperatures (25, 40 and 50 °C). Products obtained were characterized by different techniques (light and polarized microscopy, Fourier transform infrared spectroscopy (FTIR), rheology and differential scanning calorimetry (DSC)). Results obtained so far demonstrated that potato starch suspensions (20% starch–water concentration (w/w)) with granules mean size smaller than 25 µm treated at 600 MPa for 15 min and 50 °C showed a complete gelatinization and gel-like appearance. Potato HHP hydrogels were characterized by high viscosity, shear-thinning behavior and a highly structured profile (G’ >> G’’). Moreover, their FTIR spectra, similarly to FTIR profiles of thermal gels, presented three absorption bands in the characteristic starch-gel region (950–1200 cm−1), whose intensity increased with decreasing the particle size and increasing the processing temperature. In conclusion, potato starch hydrogels produced by HHP in well-defined processing conditions exhibited excellent mechanical properties, which can be tailored according to the requirements of the different applications envisaged.

EPR study of the influence of high hydrostatic pressure on the formation of radicals in phosphorylated potato starch

2010 ◽  
Vol 82 (4) ◽  
pp. 1256-1263 ◽  
Author(s):  
W. Błaszczak ◽  
E. Bidzińska ◽  
K. Dyrek ◽  
J. Fornal ◽  
E. Wenda
Keyword(s):  
Hydrostatic Pressure ◽  
High Hydrostatic Pressure ◽  
Potato Starch

Pultrusion Technology Optimization for Hybrid Fiber Composites Based on DSC and Mechanical Property Testing

2011 ◽  
Vol 295-297 ◽  
pp. 383-387 ◽  
Author(s):  
Li Chen ◽  
Qi Lin Zhao ◽  
Ke Bin Jiang ◽  
Yong Ding
Keyword(s):  
Mechanical Properties ◽  
Fiber Composite ◽  
Processing Parameters ◽  
Fiber Composites ◽  
Processing Temperature ◽  
Processing Parameter ◽  
Heating Rates ◽  
Hybrid Fiber ◽  
Scanning Calorimetry ◽  
Parameter Ranges

In the interest of improving the curing effect and mechanical properties of pultruded carbon/glass bybrid fiber composites, the DSC (Differential Scanning Calorimetry) technology was introduced and the curing DSC curves for the hybrid fiber composites at 4 different heating rates was attained. Then the range of the processing temperature for the three-stage heating pultrusion was primarily determined with T-β method. Subsequently a kind of carbon/glass hybrid composite pole with a diameter of 11mm was selected as the research object, and was manufactured with varies of processing temperatures and speeds. The produced poles were mechanically tested to investigate the effect of processing parameters on the mechanical properties of the composite, so as to further more ascertain the processing parameter ranges fitting to this material formula. As the result shows: the pultrusion processing parameters for the hybrid fiber composite acquired in this study can satisfy the require of manufacturing; compared with the traditional method that attain processing parameters by experience, the method for attaining processing parameters suggested in this paper is more efficiency, more economical and more accurate.

The Effect of High Hydrostatic Pressure on the Mechanical Properties of the Surface of the Sea-Urchin Egg

1971 ◽  
Vol 8 (1) ◽  
pp. 87-92
Author(s):  
L. WOLPERT ◽  
D. MARSLAND ◽  
M. HIRSHFIELD
Keyword(s):  
Mechanical Properties ◽  
Hydrostatic Pressure ◽  
High Hydrostatic Pressure ◽  
Significant Contribution ◽  
Cell Diameter ◽  
Urea Treatment ◽  
Plastic Sheet ◽  
Sea Urchin Egg ◽  
Resistance To Deformation ◽  
Fertilization Membrane

There is evidence that high hydrostatic pressure can solate and weaken gel-like structures within cells. It was thus of interest to determine its effect on the mechanical properties of the cell surface since it has been suggested that there is a gel-like cortex beneath the plasma membrane which makes a significant contribution to its mechanical properties. The mechanical property measured was the resistance to deformation when the eggs were compressed mechanically. The eggs of Arbacia were compressed by placing a small plate made either from a fragment of coverslip or Melinex plastic sheet on a small group of eggs (20-100) so that the eggs supported the plate. The deformation of the eggs was determined by measuring their increased diameter. The mechanical properties of the cell membrane of unfertilized eggs appear to be unaffected by high hydrostatic pressure. When compressed fertilized eggs, from which the fertilization membrane had been, removed by urea treatment, were subjected to pressure of about 7x104 kN m-2 (10000 lb/in.2) there was a significant increase in cell diameter. This increase was such that it appeared as if the resistance to deformation of the membrane were about quartered. Surprisingly after a few minutes the diameter decreased again indicating a contraction at the membrane even while under high hydrostatic pressure. Release of the hydrostatic pressure resulted in a further reduction in diameter and thus contraction at the surface, the final diameter sometimes being less than that before the hydrostatic pressure was applied.

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