The solubility was determined according to Cano-Chauca,
Stringheta, Ramos, and Cal-Vidal (2005). Approximately 1 g of the
sample was added to 100 mL of distilled water in a centrifuge tube.
The suspension was homogenized using a vortex (Quimis, Model
Q920-A2, Brazil) for 2min and centrifuged (3000g for 5 min, Sigma,
model 4K15, England). A 25 mL aliquot of the supernatant was
transferred to a beaker and placed at 105 C for approximately 5 h.
The solubility (%)was then calculated by the difference in the weight