An improved two-step saccharification of high-concentration corn starch slurries by granular starch hydrolyzing enzyme

Starch saccharification is a key step in the industrial production of syrups. A two-step saccharification of raw corn starch at high concentration (45%, w/w) using granular starch hydrolyzing enzyme (GSHE) was investigated to improve the efficiency of this process. The results showed that the two-step saccarification (reaction at 65 degrees C for 30 min, followed by reaction at 70 degrees C for 90 min) was more effective than a single-step saccarification involving reaction at 65 degrees C for 120 min. After saccharification, both the glucose content and dextrose equivalent (DE) value were 10% greater using the two-step saccharification than using a single-step saccharification. Assessing the mechanism indicated that the reduction in peak viscosity of the starch slurry was more obvious using the two-step saccharification, the water activity was higher, and the mobility of water was stronger. Thus, the two-step saccharification offers great advantages in the production of syrups using granular starch hydrolyzing enzyme. (C) 2016 Elsevier B.V. All rights reserved.