Studies on the Purification and Processing of Starch

Abstract

In general, the raw starch contains small quantities of crude protein, oil, resin, and inorganic salts as impurities. By the washing of raw starch with surface active agents, the content of protein in starch was considerably decreased and the purity of starch was rised.Furthermore, the addition of surface active agents to raw starch was found to be effective for complete inhibition of its deterioration, especially D. B. S. (dodecyl benzene sulfonate) was predominant.Then the author has studied the mechanism of preventing deterioration, and this was attributed to the combination of D. B. S. and proteins of the organisms to give a metaprotein by bacteriolysis.This phenomenon is closely related with formation of surfactant-protein complexes.In this study on fatty substances in the raw starch and removal of “fat-by-hydrolysis” by the surface active agents, it was found that fat-by-hydrolysis in starch could be removed to some degree by washing with the surfactants, as well as with the organic hydrophobic solvents such as methanol, and there might be a posibility of the surface active agents being introduced into the helix structure in starch.Furthermore, regarding the effect of fat-by-hydrolysis on physical properties of starch, it was shown that gelatinization temperature and viscosity of starch paste rised in proportion to the quantity of fat-by-hydrolysis.The investigation of the introducing of fatty acid into the starch has shown that physical properties of starch treated by surface active agents were conciderably different from untreated starch. When the starch was treated by sodium salts of fatty acids, it forms a complex with amylose, and treated starch showed a distinctive curve on the amylograph.