Integration of fluorophore-based sensor spots into food packaging systems for the non-destructive real-time determination of oxygen

Oxygen is an important filling gas for modified atmosphere food packaging. To measure the oxygen amount non-destructively in the headspace, the integration of fluorescence material into the packaging system is a meaningful method, as oxygen serves as quencher for dynamic fluorescence. In this study, the integration of fluorescencent material into packaging films using a heat-sealing process was successfully demonstrated. Real-time determination of changes in oxygen partial pressure was also possible, with some limitations. The use of the technology for the determination of food quality changes (microbiological growth and color changes) were evaluated with high-oxygen stored minced beef (7 d, 4 °C), vacuum-packed sausage “Lyoner” type and beef steak (13 d, 4 °C). The increase in total viable count to the critical value of 10⁷ CFU/g and the change of the surface color was well in common with the oxygen decrease for the high-oxygen packed minced beef. The vacuum packaged samples also showed correlations between reaching the critical microbiological value and a significant decrease of oxygen. However, no color changes were visible in that case.