High throughput non-destructive assessment of quality and safety of packaged food products using phosphorescent oxygen sensors

Intelligent and active packaging technologies have gained attention in recent time due to increased demand by the consumers and manufacturers for sustaining the quality and safety of food products, improved shelf-life as well as real time monitoring of the packaging, storage and handling processes. In this context, phosphorescence based sensors for molecular oxygen (O₂) are important tools for monitoring of packaged products, new product development and optimisation. They allow fast, reversible, real-time and quantitative monitoring of residual O₂ levels in a non-destructive manner, being superior over alternative systems. In this review, we describe the main types of phosphorescent O₂-sensitive materials, fabrication methods and general requirements for sensors for food packaging applications. The main developments and representative examples are provided which illustrate the application of such sensors for monitoring of gaseous and dissolved O₂ in various types of packaged foods and beverages. We also compare commercial O₂ sensing instrumentation and disposable O₂ sensors currently in use.