High-pressure gelatinization of wheat starch and properties of pressure-induced gels

Wheat starch suspensions of 5% dry matter were treated at 86 degrees C, 15 min, or with pressure at 600 MPa, 25 degrees C, 15 min. Both treatments wer e found to induce no further melting peak when differential scanning calori metry was used. Under these previous conditions, starch suspensions subject ed to pressure gave original products in terms of swelling index (water bin ding), amylose release and specific gravity. Pressure induced starch gelati nization with preservation of the granular structure. As a consequence, pec uliar properties were expected for pressure-induced gels of 30% dry matter obtained at 600 MPa, 25 degrees C, 15 min. By using Young modulus measureme nts, calorimetry, X-ray diffraction, and drying kinetics experiments, resul ts showed a limited retrogradation for gels obtained under pressure.