Technology optimization on steam-cooking combing with enzymatic hydrolysis modification of dietary fiber from jujube residues

The study aimed to discuss the technology of steam-cooking combining with cellulase hydrolysis on modification of insoluble dietary fiber.Extraction of IDF from jujube residues, using SDF yield as the index, the processing technologies of steam-cooking and cellulase modification were studied. Based on the single factor experiment, the technology optimization was by Box-Behnken central composite design and response surface methodology. The results showed that the steam-cooking technology of IDF from jujube residues was as follows: steam-cooking temperature 120 ℃ and treatment time 60 min, and the optimal technology for hydrolyzed of IDF by cellulase was determined as follows: enzyme concentration 0.55%, p H4.6, liquidsolid ratio 1∶ 27 g/m L, enzymatic hydrolysis temperature 43 ℃ and treatment time 2.5 h.Under these technological conditions, the SDF yield by combining steam-cooking and enzymatic hydrolysis was up to 20.03% ± 0.58%, which was very close to the predicted value of 20.37%.The regression equation of response surface was in good agreement with the experimental results, indicating that the model was reliable and will provide a reference for the industrial modification of IDF from jujube residues.