# Preparation and Study on Sulfated Nanocellulose/Anthocyanin pH-Sensitive Packaging Materials to Track Food Freshness

## TL;DR

This study creates a pH-sensitive packaging film using natural materials to monitor meat freshness by detecting changes in pH levels during spoilage.

## Contribution

A bilayer functional film using sulfated nanocellulose and anthocyanin is developed for real-time meat freshness tracking.

## Key findings

- The composite film with 6% CNC content showed optimal mechanical and thermal properties.
- The film effectively blocks UV radiation and detects spoilage through pH changes.
- The solution is low-cost, eco-friendly, and easy to use for food freshness monitoring.

## Abstract

Meat products are prone to spoilage during storage and transportation due to the decomposition of amino acids and proteins, which generates volatile amines and elevates pH levels. In recent years, research on pH indicator labels for food has significantly increased. This study investigates a functional film with a bilayer structure for real-time freshness monitoring of meat. Utilizing Tara gum (TG) and Gellan gum (GG) as the base material and nanocellulose composite GG/blueberry anthocyanins as the sensing layer, titanium dioxide was incorporated to effectively block ultraviolet radiation. Through response surface methodology, the cellulose nanocrystals (CNCs) preparation process was optimized to address issues such as insufficient mechanical properties, hydrophobicity, and thermal stability of the composite film. Results showed that the composite film achieved optimal performance when CNC content was 6%. This research provides a simple and effective solution for real-time freshness monitoring of meat products, offering advantages such as low cost, environmental friendliness, and user-friendly operation.