Granular starch conversion to fructose - in water using alpha-amylase, glucamylase and glucose isomerase mixt. under non-gelatinising conditions

摘要

Fully enzymatic starch conversion to fructose takes place by mixing a granular starch with water, bacterial alpha-amylase, glucamylase and glucose isomerase, at pH 5-7 and 40-70 degrees C but below temp. at which starch starts to gelatinise. Mixt. is pref. kept or reacted at conditions under which the starch is kept in granular form, until a soluble hydrolysate is formed in which opt. present residual starch is granular, non-gelatinised form. The enzymes act synergetically. Aq. starch suspensions used may be conc., pref. having solids content 10-70 (20-50)%. >=90% of starch present in 30-40% concn. can be solubilised and undissolved starch may be recycled, allowing recovery of enzyme activity. Solubilised starch has dextrose equiv. 90-95%.