Effect of pullulanase concentration on preparation and properties of debranched waxy maize resistant starch

The waxy maize starch was used as material in the experiments.After burning,the pullulanase was added into the paste,so that there were more amyloses produced and it is easy to reform new crystal.At the same time the content of resistant starch was increased.The experiment showed: the maximum content of resistant starch was obtained when the amount of solid was 8%(w/w),the amount of the pullulanase was added 20 ASPU/g starch which maintained at a temperature of 60 ℃ for 24 hours,the paste was incubation at 20 ℃ for 24 hours.The highest content was 27.69 %.X-ray diffraction pattern of treated starch displayed a mixture of B and V-type in which illuminatied treated starches contain crystalline structure.Scanning electron micrographs showed treated starches had more irregular shapes without granular structure.DSC determination showed that To、Tp、Tc and △H all increased,and these change had good relation with RS content.