The pervasiveness of RFID technology in novel application fields, such as agriculture and food chain integrated management, is related to the addition of sensor and computational capabilities to the systems, and as a consequence, their powering become a challenge. Passively powered devices, such as inductively coupled passive HF RFID systems, utilize an external electromagnetic field to operate without an internal power source. This paper presents a battery-less RFID sensor useful to create a safer and more manageable food supply chain of perishable comestibles.