Starch-based antimicrobial films functionalized by pomegranate peel.

Area of Science:

• Materials Science
• Food Science
• Biotechnology

Background:

• Starch-based films are biodegradable but often lack mechanical strength and antimicrobial properties.
• Pomegranate peel (PGP) is a natural source of bioactive compounds with potential antimicrobial and reinforcing capabilities.

Purpose of the Study:

• To develop novel starch-based films incorporating pomegranate peel (PGP).
• To evaluate the antimicrobial activity and mechanical performance enhancement of PGP in hydroxypropyl high-amylose starch films.
• To investigate the microstructure and material properties of the developed composite films.

Main Methods:

• Fabrication of starch-based films with varying PGP content.
• Microstructural analysis using Scanning Electron Microscopy (SEM) and Optical Microscopy (OM).
• Characterization of mechanical properties (tensile strength, Young's modulus) and barrier properties.
• Assessment of antimicrobial activity against Gram-positive (Staphylococcus aureus) and Gram-negative (Salmonella) bacteria using disc diffusion tests.
• Crystallinity analysis using X-ray Diffraction (XRD).

Main Results:

• PGP demonstrated significant inhibition of both Gram-positive and Gram-negative bacterial growth.
• Incorporation of PGP substantially increased the Young's modulus, tensile strength, and stiffness of the starch films.
• SEM and OM revealed good compatibility between starch matrix and PGP particles.
• XRD confirmed that PGP maintained its semi-crystalline structure within the film, contributing to mechanical reinforcement.

Conclusions:

• Pomegranate peel acts as an effective antimicrobial and reinforcing agent for starch-based films.
• The developed composite films exhibit enhanced mechanical properties and antimicrobial activity.
• The food-grade nature of all components suggests potential applications as edible films and sustainable food packaging.