Optimization of the Preparation of Sweet Potato Resistant Starch by Thermal-press Processing Method

The preparation of resistant starch of sweet potato was optimized by the combination of thermal-press processing and response surface analysis. Using sweet potato powder as raw material,the effects of sweet potato powder concentration,pH,thermal-press temperature,thermal-press time and refrigerating time on the yield of resistant starch of sweet potato were studied. Results showed that,the optimal conditions of preparing resistant starch of sweet potato with response surface methodology were as follows:Sweet potato powder concentration 25.50%,pH7.30,thermal-press temperature 120℃,thermal-press time 31.20 min,refrigerating time 24 h. Under these conditions,the yield of resistant starch of sweet potato was 9.41%. The yield of resistant starch of sweet potato was close to the theoretical value,and the response surface model fitted well with the actual situation,which would provide a reference for the industrialized production of resistant starch of sweet potato.