Novel Bioactive Kefiran-Based Films Enriched with Grape Pomace Extract

Area of Science:

• Materials Science
• Food Science
• Biotechnology

Background:

• Growing demand for sustainable and functional food packaging.
• Need for biodegradable materials with bioactive properties.
• Valorization of agricultural by-products like grape pomace.

Purpose of the Study:

• To develop and characterize kefiran-based films incorporating grape pomace extract (GPE).
• To evaluate the impact of GPE on physicochemical, mechanical, antioxidant, and antimicrobial properties.
• To assess the potential of these films as sustainable bioactive food packaging.

Main Methods:

• Preparation of kefiran films with varying GPE concentrations.
• Physicochemical analysis (color, thickness, UV protection, solubility, water vapor permeability).
• Mechanical testing (tensile strength, elongation at break).
• FT-IR spectroscopy for structural analysis.
• Antioxidant activity assays.
• Antimicrobial assays against Listeria monocytogenes and Escherichia coli.

Main Results:

• GPE incorporation enhanced film color (L*, a*, b*, ΔE), thickness, and UV protection.
• FT-IR confirmed interactions between kefiran and GPE phenolics without structural damage.
• GPE acted as a plasticizer, increasing tensile strength and elongation at break.
• Antioxidant activity and total phenolic content significantly increased with GPE addition.
• One formulation (3K-0.5GPE) showed antimicrobial activity against Listeria monocytogenes.

Conclusions:

• Kefiran-GPE films are a viable sustainable alternative for bioactive food packaging.
• GPE enhances functional properties and bioactive potential of kefiran films.
• This approach promotes the valorization of wine industry by-products.