Evaluation of edible film-forming ability of pumpkin oil cake; effect of pH and temperature

This study was conducted to evaluate the feasibility of pumpkin oil cake (PuOC) to form biodegradable films. The effect of heating treatment and pH of film solutions on films properties was determined. Film with the highest tensile strength (TS) (68.08 MPa) and elongation to break (EB) (36.62%) was produced when pH was 12 and heating T 90 °C. The same showed the best permeability properties. The total soluble matter and soluble protein reached the highest value, when the film was prepared at pH = 12 and T = 50 °C. ABTS test indicated that the film produced at pH = 10 and T = 60 °C was the best regarding the radical scavenging activity. Moisture content had not been significantly affected by the pH and heating temperature, whereas swelling capacity could be measured only for film prepared at T = 80 and 90 °C. To affirm and explain the influence of pH and T, scanning electron microscopy (SEM) was used.