Preparation of slowly digestible starch by α-amylase and β-amylase.

Making normal corn starch as original material,SDS was prepared by α-amylase and β-amylase respectively.The orthogonal test optimal conditions were given as follows,α-amylase: pH 6.5,enzyme reaction time of 50 min,temperature 50 ℃,α-amylase 240 U;β-amylase: pH 7.0,enzyme reaction time of 60 min,temperature 40 ℃,β-amylase 500 U.Based on these conditions,starch products prepared using α-amylase and β-amylase showed yield of SDS by 7.11% and 10.12%.Although the optimum conditions of the two methods are similar,the products prepared using β-amylase with higher yield.