Abstract:

Soluble dietary fiber (SDF) was extracted from pear residue by hemicellulase hydrolysis. The optimum extraction
conditions for SDF were determined using response surface methodology (RSM). The effects of four crucial parameters,
including liquid/material ratio, hemicellulase dosage, hydrolysis temperature and time, on the extraction rate of SDF were
investigated by single factor experiments. A Box-Behnken design (BBD) consisting of 29 experimental points with five
replications at the center point was used to investigate the interactive effects of the four independent variables at three levels
ranging from 10:1 to 18:1, from 35 to 55 U/g, from 40 to 60 ℃, and from 4 to 6 h, respectively on extraction efficiency.
The maximum extraction rate of SDF (15.21%), which agreed with the predicted value (15.38%), was obtained when the
extraction experiment was carried out for 5 h at 58 ℃ with a hemicellulase dosage of 35 U/g at a liquid/material ratio of 13:1
(mL/g). Thus, it is feasible to use hemicellulase to extract SDF from pear residue.

Key words: pear residue, soluble dietary fiber, hemicellulas