Abstract
The relation between dry and moist states of potato starch and change in physical properties of the powder (agglomeration, dispersibility, apparent specific volume and angle of repose) by the addition of various lubricants (talc, magnesium stearate, calcium stearate, synthetic aluminum silicate and hydrous silicic acid) were studied. Following results were obtained: 1) Effect of hydrous silicic acid and synthetic aluminum silicate added to dried potato starch was most potent, and that of magnesium stearate was weakest. 2) When added to moist starch, hydrous silicic acid and synthetic aluminum silicate were most effective, but it was notable that calcium stearate, which was not so effective when added to dried starch, proved effective in moist starch. Almost all of the lubricants proved more effective in moist starch than in dried starch. 3) The effect of hydrous silicic acid added to dried starch was not changed even after the starch was moistened. All other lubricants reduced their effect after moistening. Especially, the lubricant effect of talc and magnesium stearate was lost when the water content of starch exceeded about 13%.
