UAE is a process that uses acoustic energy and selected solvents to extract specific compounds from
various matrices in relatively short times giving high yields. The mechanism of UAE is based on the
interaction of the ultrasound waves and the solvent molecules allowing the acoustic cavitation and the
disruption of cell walls with enhanced mass transfer across the cell membranes [20]. High efficiencies
were recently reported for the UAE of pectins from several agricultural wastes, such as pomegranate
peel [46] and sisal fiber [47]. In both cases, BBD was successfully used as valuable multivariate technique
to evaluate the relationship between variables, helping to determine the accurate optimum values of all
the experimental parameters with a reduced number of experiments [55]. In pomegranate peel, the effects
of pH, S:L ratio, extraction time and temperature on the recovery of pectins were studied [46].
The maximum extraction yields were determined at pH = 1.27; 28.3 min 1:17.5 g·mL−1 S:L ratio and
61.9 °C resulting in yield extraction of 24.2%. In sisal fibers, the extraction conditions were also
optimized [47]. The analysis of variance showed that the contribution of a quadratic model was
significant for the pectins extraction yield. The optimal extraction condition were 61 W, 1:28 g·mL−1 S:L ratio, 26 min and 50 °C resulting in pectins yield of 29.3%. Therefore, UAE was proposed as an
alternative method to extract pectins from sisal waste with the advantages of lower extraction temperatures
and energies and shorter extraction times.