NIT-R Develops pH-sensitive film to monitor seafood freshness

June 4, 2025 Innovation Valli Sarvani

Innovations in food packaging are evolving beyond protection, and Indian researchers have taken a major step forward.

A team at the National Institute of Technology-Rourkela (NIT-R) has developed a pH-sensitive, biodegradable packaging film that monitors seafood freshness in real-time.

This smart film uses spoilage indicators to detect volatile amines, compounds released as seafood spoils.

Unlike conventional packaging, this film offers visual cues. It changes colour from red (fresh) to yellow (spoiled) within 48 hours.

The change signals the food’s condition clearly, helping consumers and suppliers alike.

The film’s base material is starch extracted from Kodo millet, an underutilised grain.

Researchers combined it with gum tragacanth, a natural plant gum, and beetroot peel extract.

The beetroot extract contains betalains, pH-sensitive pigments known for their antioxidant and antimicrobial properties.

Dr Preetam Sarkar, Associate Professor in Food Process Engineering at NIT-R, who led the project, explained that they soaked, ground, filtered, and dried Kodo millet to extract starch.

He added that they separately prepared beetroot peel extract and combined it with gum tragacanth and glycerol before casting the films and testing their sensitivity.

This innovation stands out for its use of organic, safe, and eco-friendly materials.

It eliminates the need for invasive freshness testing and supports sustainable packaging efforts.

The development is timely. India is the world’s second-largest fish producer and among the top five shrimp exporters. Ensuring seafood quality is crucial for both domestic consumption and exports.

The team is now working with seafood industry stakeholders to explore real-world applications. On a commercial scale, the film may cost ₹400 to ₹600 per kilogram, making it affordable and effective.

By integrating freshness monitoring directly into the packaging, this intelligent film could reduce food waste, improve safety, and transform seafood logistics.

This research marks a significant innovation in smart food packaging, merging sustainability, safety, and simplicity in one smart wrap.

Image from Pxhere (Free for commercial use / CC0 Public Domain)

Image Published on March 10, 2017