Abstract:  Based on the optimization parameters of pullulanase, the method of pullulanase in conjunction with termostableα-amylase was used to produce RS. With the degree of polymerization (DP) changing during this process, the relationship between DP of corn starch and the yield of resistant starch was analysised. This study illustrated that increasing in amylose content and limited DPn of starch significantly affect the yield of RS. The curve of DSC (differential scanning calorimeter) and X-ray diffraction indicated that there was significant difference between the crystal of native starch and RS(resistant starch).

Key words: resistant starch, corn starch, degree of polymerization