Film solubility in water (WS) was defined as the content of dry matter solubilized after 24 h of
immersion. Water solubility of each film was measured according to the method described by Rhim at al.
. Three randomly selected samples from each film were first dried at 110°C for 6 h to determine their
initial dry weights. Then, they were placed in a 80-mL beaker containing 40 mL of distilled water. Beakers
were covered with parafilm and stored at room temperature for 24 h with occasional gentle stirring. The
weight of undissolved dry matter was determined by removing the film pieces from the beakers, gently
rinsing them with distilled water, and oven-drying them (110°C, 6 h). The weight of water-soluble matter
was calculated by subtracting the weight of undissolved dry matter from the weight of initial dry matter and
expressed as a percentage of the initial dry matter content.