The aim of this study was to improve the hydrophobic and antimicrobial properties of edible films by replicating the geometric structures of selected plant leaves. Soy protein isolate (SPI) films were prepared using the solvent casting technique on negative templates of lotus, cabbage, and leek leaves to simulate their surface topographies. Since surface morphology plays a critical role in reducing bacterial biofilm formation, the prepared films were characterized by measuring contact angle, water vapor permeability, and mechanical properties, while antimicrobial activity was evaluated through bacterial analysis according to international standards. The results showed that bioinspired structuring significantly enhanced water resistance, with the lotus leaf template providing the greatest improvement. The contact angle of the lotus-inspired coating reached 140°, compared to 45° for the control sample, indicating a substantial increase in hydrophobicity. Bacterial analysis confirmed that the lotus leaf surface exhibited the highest antibacterial activity, as banana fruit wrapped in this coating showed the lowest bacterial count (2.2 CFU/g). Mechanical testing revealed that tensile strength decreased slightly by 5%, while elongation at break improved by 26% and hardness increased by 30% compared to the control. These findings demonstrate that edible films inspired by plant leaf surfaces can achieve a balance between enhanced hydrophobicity, antimicrobial activity, and acceptable mechanical performance. The approach highlights the potential of bioinspired edible films as sustainable food packaging materials that reduce reliance on synthetic plastics and contribute to environmentally friendly preservation strategies.
Ghanem et al. (Thu,) studied this question.