Fabrication and characterization of composite films composed of Camelina seed protein isolate and Persian gum

Camelina seed protein isolate (CSPI; 3–5 g), Persian gum (PG; 35, 42.5, and 50% w/w, based on the dry weight of CSPI), and glycerol (GLY; 35, 42.5, and 50% w/w, based on the dry weight of CSPI) were used to prepare edible protein-based films. The central composite design (CCD) was employed to develop an experimental framework using surface methodology (RSM). Regression models were employed to characterize the relationships between variables by fitting a line to the observed data. The optimization process aimed to minimize opacity (9.96), water solubility (50.75%), water vapor permeability (1.89 g mm/kpa h m 2 ), and total color differences (68.93), while maximize thickness (0.216 mm), tensile strength (2.41 MPa), elongation at break (13.422%), L* (48.81), and contact angel (48.45°). By applying the optimization procedure utilizing RSM, the formulation containing CSPI (4.208 g), GLY (33.45% w/w based on the dry weight of CSPI), and PG (50% w/w based on the dry weight of CSPI) exhibited superior physicochemical characteristics in the final film structure. FTIR spectra of obtained films showed the typical peaks of protein (amide I and amide II) and confirmed the hydrogen bond formed between CSPI, PG, and GLY. X-ray diffraction patterns of the CSPI showed an amorphous structure, which was also confirmed by the SEM study. These results highlight the potential of CSPI for producing edible films with a homogeneous structure and favorable physicochemical properties, which can be further explored in future research.