Stability and Safety Assessment of Phosphorescent Oxygen Sensors for Use in Food Packaging Applications

Abstract

Five types of new solid-state oxygen sensors, four based on microporous polypropylene fabric materials and one on polyphenylene sulphide films impregnated with phosphorescent platinum(II)-benzoporphyrin dye, were tested for their stability and safety in food packaging applications. All these sensors exhibit useful optical signals (phosphorescence lifetime readout) and working characteristics and are simpler and cheaper to produce and integrate into standard packaging materials than existing commercial sensors. When exposed to a panel of standard food simulants and upon direct contact with raw beef and chicken meat and cheddar cheese samples packaged under modified atmosphere, the sensors based on ungrafted polypropylene fabric, impregnated with PtBP dye by the swelling method, outperformed the other sensors. The sensors are also stable upon storage under normal atmospheric conditions for at least 12 months, without any significant changes in calibration.

A Simple Sensor System for Onsite Monitoring of O2 in Vacuum-Packed Meats during the Shelf Life

“…It is worth noting that, according to the industry standards, the residual O 2 levels in commercial VP meat packs should be maintained below 0.3-0.5% [2,3,6]. The results also reflect good stability of sensors in such applications [22,23,26].…”

“…It is worth noting that, according to the industry standards, the residual O2 levels in commercial VP meat packs should be maintained below 0.3-0.5% [2,3,6]. The results also reflect good stability of sensors in such applications [22,23,26]. To demonstrate that the O2 sensor system provided meaningful information about the quality of the individual packaged meat samples in a simple and nondestructive manner, we measured several conventional parameters and readouts of meat quality and analysed and compared them to each other.…”

“…The O 2 sensors were intended for off-line testing of batches of packaged meat samples which were discarded after testing. In this case, sensor toxicity was not an issue, also considering that high safety and stability and low toxicity had been demonstrated for similar types of sensors [ 22 , 23 , 26 ].…”

“…Some O 2 sensors are commercially available or can be manufactured on a large scale using relatively inexpensive materials and equipment [ 8 ]. Robust, long-term and periodic monitoring of the residual O 2 levels in packs with disposable O 2 sensors has been demonstrated in various food and nonfood applications [ 17 , 19 , 21 , 22 , 23 ]. Optical O 2 sensing systems have previously been applied using commercial O 2 sensors to monitor the evolution of meat spoilage in VP samples of raw beef and to analyse the efficiency of different vacuum packaging machines [ 24 ].…”

Optical Chemosensors and Biosensors

“…A comparative study of five differently stable types of phosphorescence-based oxygen sensors for food packaging applications was conducted by Kelly at al. [17]. When exposed to a panel of standard food simulants and upon direct contact with raw meat and cheese samples packaged under a modified atmosphere, the sensors based on ungrafted polypropylene material and impregnated with phosphorescent dye by the soaking method were shown to provide the best implementation in terms of stability and performance.…”