Abstract: Navel orange residue was treated with cellulase to extract soluble dietary fiber. Extraction parameters including extraction temperature, cellulase dose and length of extraction time were optimized using Box-Behnken design and response surface methodology based on single factor investigations for achieving maximum yield of soluble dietary fiber. A regression equation reflecting the relationship between the yield of soluble dietary fiber and the extraction parameters was set up. The optimal extraction parameters were found as follows: extraction temperature, 48 ℃; cellulase dose, 1.25%; length of extraction time, 5 h. Under the optimized conditions, the actual yield of soluble dietary fiber was 13.11%, close to the predicted value of 13.14%.

Key words: navel orange residue, soluble dietary fiber, response surface methodology, optimization