###### Abstract  
This study aimed to determine the effects of the ozone treatment of film-forming solutions (FFSs) containing whey protein concentrate (WPC) and gelatine on biopolymer films' physical, mechanical, and thermal properties. Film samples were produced from a FFS that was ozone-treated at 0 (control), 5, 10, and 30 min. Ozone treatment caused an increase in the pH values of the FFS, whereas the zeta potential remained negative. The films became lighter in colour, slightly greenish, and more opaque with longer ozonation times. The control sample showed the highest thermogravimetric weight loss (92.15%). The weight loss of the samples decreased with increasing ozone treatment time. The application of ozone treatment on the FFS enhanced the films' mechanical properties. Increased ozone treatment time improved the film samples' tensile strength, elongation at break, and toughness values. In conclusion, the results of this study demonstrate that the ozone treatment of FFS containing whey protein concentrate and gelatine can significantly enhance the physical, mechanical, and thermal properties of biopolymer films. These results highlight the potential of ozone treatment as a viable method for improving the performance and quality of biopolymer films used in food packaging, offering promising advantages for sustainable and environmentally friendly packaging solutions. ozone treatment; whey protein concentrate; edible film; biopolymer film production Article]Gelatine-Based Biopolymer Film Produced from Ozone-Treated Film-Forming Solutions Containing Whey Protein Concentrate: Effects on Physical, Mechanical, and Thermal Characteristics April 2024 14  
sile strength and elongation at break when compared to plastic films like high-density polyethylene and low-density polyethylene [8]. For use in food packaging, biopolymer films developed through the modification of WP have demonstrated improved physical, optical, morphological, mechanical, and barrier characteristics compared to native WP films. Previous research has indicated the application of some methods that modify whey protein structure to produce modified biopolymer films, such as chemical treatments using carbonyldiimidazole, glutaraldehyde, and formaldehyde [9], the addition of transglutaminase [10], the application of \(\gamma\)-irradiation [11], sonication treatment [12], and UV application [8]. Ozone (O\({}_{3}\)) is a form of oxygen that has strong oxidising properties. It naturally decomposes and releases the third atomic oxygen. O\({}_{3}\) is considered safe for use and has been approved by the Food and Drug Administration (FDA) as an antimicrobial ingredient for food processing [13]. Ozone treatment (OT) reduces food production costs without having a hazardous impact on the environment as it prevents hazardous residues from remaining on food or in areas where food is processed. Excess ozone rapidly breaks down into oxygen without causing further pollution [14]. OT provides a broad spectrum of disinfection by increasing the oxidation potential. Bacterial cells, spores, viruses, and fungi can be inactivated and botulinum toxin eliminated during the OT process [15]. In addition to its antimicrobial properties, OT has the potential to alter the structure and functionality of proteins due to its high oxidative potential. Previous studies have focused on the impacts of OT on the chemical, structural, and functional properties of WP [16; 17]. The authors specifically reported that WP's structure, solubility, and emulsifying and foaming characteristics were modified by ozone. The impacts of ozone treatment in film production have been studied in both potato starch [18] and cassava starch [19; 20]. In most instances, it was reported that ozone treatment modified the appearance and mechanical characteristics of the films. Biopolymer films should be suitable to ensure food safety as a food packaging material.