An Intelligent Indicator Film Based on Food Derived Materials for Real-Time Visual Monitoring of Salmon Freshness

Determining the freshness of aquatic products during food processing, transportation, and preservation is critical for ensuring food safety and quality. In this study, we developed intelligent indicator films sensitive to nitrogen compounds using sodium alginate, glycerol, and natural pigments. These films exhibited excellent indicating performance in monitoring the freshness of salmon, including total volatile basic nitrogen (TVB-N), thiobarbituric acid-reactive substances (TBARS), and pH levels. Additionally, the intelligent indicator films exhibit both thermal stability and good biocompatibility. This finding paves the way for developing safe and effective food freshness indicators with potential uses in transportation, packaging, and related industries.