Optimization of biodegradable film production containing aqueous extract of Chubak root and nanoemulsion of rosemary essential oil based on gelatin by response surface methodology

In this study, different concentrations of aqueous extract of Chubak root (at levels of zero, 0.5, 1, 1.5, and 2%) with different concentrations of rosemary essential oil nanoemulsion (zero, 0.5, 1, 1.5, and 2%) was used to optimize the production of biodegradable gelatin-based film. Test responses were statistically significant for all fitted regression models at 99% confidence level. To optimize film production, maximum transparency, contact angle, tensile strength, Elongation at Brake to the point of rupture and minimum solubility, swelling and vapor permeability were evaluating. After fitting the models, the results showed that the effect of aqueous extract of Chubak root and rosemary essential oil nanoemulsion on all responses was significant (P <0.05). Increasing the aqueous extract of Chubak root and nanoemulsion of rosemary essential oil increased the thickness, contact angle and Elongation at Brake to the point of rupture and decreased moisture content, vapor permeability, transparency, solubility, tensile strength and swelling. Based on the results of model prediction and comparison with experimental values, aqueous extract of Chubak root at a concentration of 2% and nanoemulsion of rosemary essential oil with a concentration of 0.77% were obtained as optimal values.