Measurement of electrical conductivity, differential scanning calorimetry and viscosity of starch and flour suspensions during gelatinisation process

Electrical conductivity measurements were applied to analyse the gelatinisation process of 12 starch or flour suspensions. The electrical conductivity of starch suspensions was found to increase upon gelatinisation because of the release of ions from starch granules. The initiation temperature of ion release, Ti, correlated well with the onset temperature in the DSC thermogram (R = 0.868), while the completion temperature of ion release, Tf, correlated with the temperature at the start of viscosity increase (R = 0.865). Thus Ti and Tf corresponded to the beginning and ending temperatures of gelatinisation respectively. The electrical conductivity measurement will be used as an on‐line technique to monitor the whole process of starch gelatinisation. © 2001 Society of Chemical Industry