Production and characterization of edible film containing işkin (Rheum ribes L.)

In this study, the production and characterization of twelve edible films containing ışkın were made. Two completely different methods were used for this purpose. In method A, ışkın samples were added to the starch-based films as a puree. In method B, Işkın obtained by freeze-drying method were added to chitosan-based films in varying proportions (0.5%, 1%, 1.5%, and 2%). In the film samples obtained that film thickness, water vapor permeability, tensile strength and elongation coefficient, color properties, antioxidant activity (FRAP, DPPH, and ABTS), FT-IR, SEM, thermal gravimetric analysis (TGA), biodegradability, water-solubility, absorbance, transmittance value, and antimicrobial activity analyzes were performed. As a result of these studies, the thickness values of the film samples obtained in method A are between 0.163 ± 0.005-0.277 ± 0.016 mm, the water solubility value is in the range of 91.78%-95.47%, the elongation coefficient is 67.94 ± 0.29% and 59.14%±2.35%, tensile strength between 0.64 ±0.01 MPa and 0.34±0.01 MPa. It was determined that the films obtained by this method completely deteriorated after 120 hours. Water vapor permeability was found between 0.02 gmmh-1cm-2Pa-1x10-6 and 2.41 gmmh-1cm-2Pa-1x10-6. The thickness of the film samples obtained from method B was found in the range of 0.162 ± 0.001-0.225 ± 0.004 mm. It was observed that the addition of ışkın increased the thickness slightly. Solubility values in water were found between 81.08% and 88.96%. The elongation coefficient was found between 88.33±11.82% and 52.07±0.84%, and the tensile strength between 2.17±0.189 MPa and 1.16±0.011 MPa. As a result of the analyzes performed at 5-day intervals for 30 days within the scope of method B, it was determined that the films obtained at the end of 30 days provided a degradation in the range of 78.33±0.96%-97.79±3.13%. Water vapor permeability was determined between 0.02 gmmh-1cm-2Pa-1x10-6 and 3.2 gmmh-1cm-2Pa-1x10-6. It was determined that the films obtained by both methods had a yellow-green shade, Işkın and the film skeletons did not interact with any chemical bond, moreover, the addition of Işkın increased the antioxidant properties. However, it was determined that the film samples did not exhibit antimicrobial properties on Staphylococcus aureus and Salmonella paratyphi. After producing PK-2%-JN sample in method A, it was evaluated as the most ideal film sample, while in method B, KK-0.5% film was decided to be the ideal sample. It is thought that research should be done on the use of the films tried on foods in the next stage.