Study on ultrasonic-enzyme technology for production of slowly digestible starch

Slowly digestible starch is a new-type of functional starch and it has many physiological functions.Maize starch is used as raw material,ultrasonic-enzyme technology isused to prepareslowly digestible starch.The principle was:the pullulanase could debranching the chain of the starch,shortenthe length of the chain inthe starch.At the same time,the ultrasonic was absorbed by the starch milk,shattered the long chain of starch.On the other side,when ultrasonic work with the pullulanase on the starch solution,the action time was shortened andthe speed of enzyme actionwas increased.By controlling the reaction conditions,we get the best preparation of slowly digestible starch.The best condition was:ultrasonic power 300W,the pullulanase quantity 14%,the reaction time 40min at 40℃.Three repeated experiments were carried out under the above conditions and the yield of slowly digestible starch was 43.14%.