Abstract:

The ultrasonic-assisted enzymatic extraction of soluble dietary fiber (SDF) from old leaves of Toona sinensis was
optimized using response surface methodology. Extraction efficiency was affected in decreasing order by ultrasonication
time, cellulase dosage, pH and temperature, and the optimum extraction conditions for these four parameters were 53.0 min,
0.50%, 6.0 and 60.0 ℃, respectively. Under the optimized conditions, the extraction yield of SDF was 7.11% with low levels
of impurities. The water holding capacity and expansibility of SDF products were 7.29 g/g and 4.40 mL/g, respectively.

Key words: Toona sinensis, soluble dietary fiber, cellulase, ultrasonic, response surface methodology