A Novel Intelligent Indicator Film: Preparation, Characterization, and Application

Area of Science:

• Food Science and Technology
• Materials Science
• Biotechnology

Background:

• Intelligent indicator films are emerging in food packaging for quality monitoring.
• Whey protein isolate nanofibers (WPNFs) offer a promising base for functional films.
• Colorimetric indicators are crucial for real-time food spoilage detection.

Purpose of the Study:

• To develop and characterize an intelligent indicator film for detecting food quality changes.
• To utilize anthocyanin (ACN) as a pH-sensitive color indicator within a whey protein isolate nanofiber (WPNF) matrix.
• To assess the film's suitability for monitoring salmon freshness through pH-dependent color changes.

Main Methods:

• Preparation of a novel edible film using WPNFs, pullulan (PU), anthocyanin (ACN), and glycerol (Gly).
• Incorporation of ACN as a color indicator and Gly as a plasticizer.
• Evaluation of the film's color change in response to varying pH levels.
• Assessment of the film's performance in detecting changes in salmon quality parameters (pH, hardness, chewiness, resilience).

Main Results:

• The WPNFs-PU-ACN/Gly film exhibited improved hydrophobicity and oxidation resistance.
• A distinct color shift from dark pink to grey was observed with increasing pH.
• The film's color change correlated directly with the pH changes in deteriorating salmon.
• The colorimetric response was consistent with changes in salmon's texture properties.

Conclusions:

• The developed WPNFs-PU-ACN/Gly edible film is effective for sensing pH changes, making it suitable for monitoring salmon spoilage.
• This intelligent indicator film demonstrates potential for enhancing food safety and quality assurance in food packaging.
• The integration of natural colorants like ACN into WPNF-based films offers a sustainable approach to smart food packaging.