Interaction of Hazelnut-Derived Polyphenols with Biodegradable Film Matrix: Structural, Barrier, and Functional...

Area of Science:

• Materials Science
• Food Science
• Green Chemistry

Background:

• Valorization of agricultural by-products is crucial for sustainable industries.
• Hazelnut skins and shells are rich in bioactive polyphenols.
• Biodegradable packaging offers an eco-friendly alternative to conventional plastics.

Purpose of the Study:

• To valorize hazelnut skins and shells into polyphenol-rich extracts.
• To develop active biodegradable films by incorporating these extracts into poly(vinyl alcohol)/carboxymethyl cellulose (PVA/CMC).
• To evaluate the structural, mechanical, thermal, barrier, and antioxidant properties of the developed films for active food packaging.

Main Methods:

• Pressurized hot water extraction (PHWE) was used to obtain polyphenol extracts from hazelnut by-products.
• Extracts were incorporated into PVA/CMC films at varying concentrations (1-3%).
• Films were characterized using FTIR, DSC, XRD, mechanical testing, barrier property analysis, and antioxidant assays. Application tests were performed on fresh-cut produce and meat products.

Main Results:

• PHWE yielded polyphenol-rich extracts (25.4 mg GAE/g dw from shell, 83.7 mg GAE/g dw from skin).
• Incorporation of extracts into PVA/CMC films enhanced UV-blocking, antioxidant activity (up to 5-fold), and reduced oxygen permeability by 69%.
• Films showed improved mechanical properties (39% increase in elongation at break) and significant reductions in microbial growth and lipid oxidation in food products.

Conclusions:

• Hazelnut by-products can be effectively valorized into bioactive extracts for functional food packaging.
• The developed active biodegradable films demonstrate excellent antioxidant and antimicrobial properties.
• This approach offers a sustainable solution for food preservation and waste valorization in the nut industry.