pH-Responsive Chitosan Films Enriched with NADES-Extracted Wine Lees Anthocyanins for In Situ Food Monitoring.

Area of Science:

• Materials Science
• Food Science
• Biotechnology

Background:

• Plastic pollution from food packaging is a significant environmental and nutritional concern.
• There is a growing need for real-time food monitoring systems for consumers.
• Biodegradable and intelligent packaging solutions are essential for sustainable food systems.

Purpose of the Study:

• To develop and evaluate biodegradable, pH-responsive chitosan films enriched with anthocyanins from wine lees.
• To optimize anthocyanin extraction methods for film preparation.
• To assess the film's potential as an intelligent food packaging material.

Main Methods:

• Ultrasound-assisted extraction and screening of Natural Deep Eutectic Solvents (NADES) for anthocyanin recovery.
• Chitosan film preparation using optimized anthocyanin extract.
• Evaluation of film's pH sensitivity, mechanical properties, UV permeability, and antioxidant activity.
• Application testing for pork meat freshness detection.

Main Results:

• Choline chloride: butylene glycol (1:4) at 50% v/v in water yielded optimal anthocyanin recovery.
• The developed films showed excellent colorimetric response to pH changes (ΔE > 6.8).
• Films exhibited improved mechanical properties, near-zero UV permeability, and a 6.1-fold increase in antioxidant activity.
• The film successfully detected pork meat spoilage with a ΔE of 15.3.

Conclusions:

• The developed anthocyanin-enriched chitosan film is a promising intelligent, bioactive, and biodegradable food packaging material.
• This sustainable packaging solution addresses plastic pollution and enhances food monitoring capabilities.
• The film's pH-responsive color change offers a visual indicator of food freshness.