Abstract:

Response surface methodology was applied to optimize the ultrasonic-assisted extraction of total triterpenoids
from apple pomace of ‘Fuji’ variety. Particle size of apple pomace, liquid/solid ratio, ethanol concentration, extraction time
and temperature were chosen to carry out single factor experiments, and the former three factors were recognized as the
independent variables with significant influence on the yield of total triterpenoids using Plackett-Burman design. The three
factors were further optimized using response surface methodology based on a three-level, three-variable Box-Behnken
design. By analyzing the response surface plots, the optimal levels for particle size of apple pomace, liquid/solid ratio,
ethanol concentration were determined as 100 mesh, 12:1 (mL/g) and 100%, respectively. Experiments conducted under the
optimized conditions led to an extraction yield of (7.10 ± 0.01)%.

Key words: total triterpenoids from apple pomace, ultrasonic-assisted extraction, Plackett-Burman design, Box-Behnken design, process