Innovative design of bio-functional Persian gum-based edible films by incorporating crocin and cinnamaldehyde: Free versus single and double emulsion fabrication techniques

The objective of this research was to fabricate a new generation of bio-functional Persian gum-based films via the co-delivery of crocin and cinnamaldehyde. Different loading strategies using single W/O and O/W emulsions and W1/O/W2 double emulsions were used to find how the distribution of bioactives in the film suspension can modify their physicochemical and biological properties compared to those prepared with the free forms of bioactives. The incorporation of emulsion structures significantly decreased the surface tension of film-forming solutions, but their viscosity remained relatively constant. The good compatibility between Persian gum and cinnamaldehyde/crocin was confirmed by FTIR and XRD. The optical, mechanical, and microstructural attributes of the films were more affected by the incorporation of the free form of bioactives. The UV–Vis light barrier property and hydrophobicity of the film were improved after incorporating single and double emulsions. However, the greater stability of bioactives within double emulsion against different pH (2 and 7) and temperatures (25 and 75 °C) produced more superior antibacterial and antioxidant activities. Furthermore, the homogenous distribution of double emulsion in the film matrix led to more resistant and extensible films.