Feasibility and characterization of the cycloamylose production from high amylose corn starch

Background and objectives Cycloamylose (CA), a promising encapsulating agent, was efficiently produced from high amylose corn starch (HACS, HYLON (R) VII) by sequentially combined enzyme treatment of isoamylase and Thermus aquaticus 4-alpha-glucanotransferase (TA alpha GT). The CA production performance of HACS was compared with that of rice starch (RS), especially from the viewpoint of differences in their molecular characteristics. Findings Conclusions The maximum conversion yield of CA from HACS reached 76.35%, which was 2.4 times higher than that of RS (31.36%). The degree of polymerization (DP) of CA produced from HACS ranged from 7 to 41, where a major portion lied in DP 23-41, with DP 26 showing the highest yield. In contrast, CA produced from RS showed a relatively larger amount of smaller cyclic glucans (DP 6-16). The significantly high production yield and DP profile of CA were attributed to high apparent amylose content and long average amylopectin branch chain length of HACS compared to those RS. Significance and novelty This study can provide a better understanding of CA production depending on starch molecular characteristics and attract industrial consideration in utilizing HACS for CA production.