Effect of salts and sugars on pressure-induced gelatinisation of wheat, tapioca, and potato starches

The impact of a variety of chlorides, sodium salts, potassium salts and low-molecular sugars on pressure-induced gelatinisation of wheat, tapioca and potato starches has been investigated. Just as thermal gelatinisation, pressure-induced gelatinisation is influenced by solutes in the starch suspensions. In general the effects of salts and sugars on starch gelatinisation were comparable for thermal and pressure treatments. For example, the gelatinisation pressure was reduced by sugars whereas the degree of gelatinisation was linearly correlated with the number of equatorial hydroxyl groups. The influence of salts on the gelatinisation pressure varied and the extent of effect on the gelatinisation pressure did not only depend on the solute added but also on the type of starch. At high chloride concentrations (> 2 M) the impact of the salts on starch gelatinisation augmentation followed the order Na+< K+< Li+< Ca2+, which corresponds to the order of the lyotropic series. At concentrations above 1 M the effect of potassium salts on starch gelatinisation upon pressurisation also followed the order of the Hofmeister series (Cl-< Br-< I-< SCN-).