The effect of heating rates on functional properties of wheat and potato starch-water systems

- The effect of heating rate on properties of potato and wheat starches was investigated.
- High heating rate resulted in an increase of granule swelling and gelatinization parameters.
- Hardness and gumminess of both starches were affected by the heating rate applied.
- The consistency index of starch based gels decreased when the heating rate increased.
- Heating rate has to be taken into account in starchy-based food process designing.

The effect of heating rate on structural and functional properties of wheat and potato starch-water systems were analyzed in term of gelatinization, swelling and pasting behavior as well as in terms of textural and flow characteristics of gels recovered. Gelatinization temperatures and enthalpy of starch increased with increasing heating rate. Viscosities measured during the pasting procedure increased with the heating rate as a consequence of granule swelling. Slower heating rates resulted in smaller breakdown of viscosity during the pasting procedure. Both wheat and potato starch gels showed shear thinning behaviours, with a consistency index decreasing when the heating rate increased. The hardness of wheat starch gels slightly decreased when the heating rate increased while the hardness and gumminess of potato starch gels increased with the heating rate.