Relationship Between Electrical Conductivity and Water Activity of Starch-Water Composites

摘要

The importance of the role of water on electrical conductivity of starch-water composites has shown the positive relationship between electrical conductivity and water activity. The gelatinization process diminishes both electrical conductivity and water activity, due to the molecular rearrangement in the composite; this phenomenon was evident in enthalpy values calculated from DSC data, which had a positive relationship with water activity and a negative relationship with electrical conductivity. Starch source was also important because of differences in granule size; rice starch had a higher electrical conductivity than corn and potato starches and the smallest starch granules. It was also shown that the highest electrical conductivity was noted for starch-water ratio, as the highest electrical conductivity was registered for the highest starch-water ratio.