Study on technology of removing starch from sweet potato marc

Starch in the sweet potato marc has seriously affected the purification of sweet potato pectin, and it must be removed from the sweet potato marc. The optimal parameters of removal starch were as follows:the ratio of the sweet potato marc and water 1∶15, the sweet potato marc liquid pH6.0, temperature 90℃ , reaction time 30min by high temperature α -amylase, and then pH4.5, 60℃ , time 180min by glucoamylase and pullulase, and the conversion of starch was 94.22% ±3.43% . According to the figure of scanning electron microscope, the starch in the sweet potato marc was successfully removed. Reseach showed that it had satisfactory effect to remove the starch from the sweet potato marc by use of high temperature α -amylase, glucoamylase and pullulase. The study was of significance to remove the starch in the sweet potato marc.