Optimization of extraction process of soluble dietary fiber from sweet potato leaves

To extract the soluble dietary fiber( SDF) from sweet potato leaves by ultrasonic technology,the effects of single factors including citric acid concentration,solid to liquid ratio,ultrasonic power and time,and extraction temperature on extraction were investigated. The extraction conditions were optimized by Box- Benhnken central composite design and response surface methodology.The results indicated that the optimum extraction conditions were as follows: citric acid concentration 4%,solid to liquid ratio 1∶ 35,ultrasonic power 240 W for 21 min at 60 ℃.Under these conditions,the yield of SDF was 4.37% ± 0.04%.This method had a better extraction effect,which was easy to operate and could save time.