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High pressure processing (HPP) is applied to preserve foods such as oysters and guacamole and combinations of high pressure and temperature to sterilize low-acid foods are the focus of intense studies to expand this technology in the commercial market.  The application of HPP induces physical changes in the constituents of foods.  We examine the ability of high pressures at room temperature (25 °C) to transform wheat, corn, and potato starch pastes into gels, and compare pressure-formed gels to those formed by thermal treatment.  The physical properties of the gels are characterized in terms of proton relaxation times (T₁ and T₂) measured using time-domain nuclear magnetic resonance spectroscopy, melting curves using differential scanning calorimetry (DSC), and birefringence using optical light microscopy.  The global T₁ and T₂ relaxation times are converted into distinct water population distributions using WinDXP software to characterize the effects of pressure on the gel and the changes in water mobility states during storage at 4 °C.  The kinetics of starch retrogradation are also evaluated during storage using DSC thermogram data.  The effects of high pressure on starch will also be compared to the pressure-induced inactivation of test microorganisms such as E. coli, Listeria monocytogenes, and B. stearothermophilus spores.  These results furnish insight into the effect of HPP has on starch, a major constituents in many food proposed for commercial potential using HPP.