Résumé
In 2015, the United Nations adopted SDG (Sustainable Development Goals) that states to reduce FWI (FoodWaste Index). To comply with this, food market must use strong logistic management and extend products shelf-life. World Health Organization (WHO) estimated that more than 600 million foodborne disease have beendeclared in 2010 and these diseases led to numerous fatalities including death and disabilities [1]. In United Statesof America, many years of improvements in food safety regulations have not dramatically reduced the risks [2].Between 1993 and 1997, 37 % of foodborne disease are due to improper storage temperature. This led to successof Time-Temperature Indicator (TTI). But, among the remaining cases, only 11 % foodborne disease are due toimproper cooking. Spoiled food must be discarded before cooking, and monitoring must target other variablesincluding food package gas concentration. Using bio-sourced biopolymer sensors are suggested for this need.Their dielectric properties have proven to be sensitive to environmental gas changes that are related to foodspoilage [3].To address logistics needs (i.e., non-line of sight and long-range reading) and SDG waste reduction, battery-lessUHF RFID (RAIN compliant) transponder layout is chosen. The developed transponder antenna is a curved-dipoleT-match. A biopolymer layer is used to tune the antenna and to make it sensitive to gas concentration. And, tobetter sense biopolymer permittivity, interdigitated electrodes take place between its T-match stubs, as describedin Figure 1. In this paper, experiments in real food packaging conditions are presented to prove that developedsolution can successfully track food packages through their shelf-life. To emulate real conditions, beef meat isstored in Modified Atmosphere Packages (MAP) consisting of 30 % CO2 and 70 % O2. Food spoilage is monitoredusing humidity logger, microbiological tests, colorimetry, and subjective visual aspect. Over RFIDcommunication measurements, forward transponder turn-on power is preferred. So, surrounding perturbation islimited to one-way signal trip. As of now, RFID measurements must stay with same distance between reader andtransponder, and with same environment. According to previous experiments with humidity or gaseous changes[4], 3 steps differentiate in Figure 2. Between start to second day, it is ambient atmosphere to MAP stabilization.Then, signals are steady for 5 days. Finally, they rise again with exponentially growing microbiological activityand with related gaseous changes inside the foodpackaging. Resulting RAIN transponder can sensefood spoilage in MAP.