Carbon Dioxide and Oxygen Gas Sensors-Possible Application for Monitoring Quality, Freshness, and Safety of Agricultural and Food Products with Emphasis on Importance of Analytical Signals and Their Transformation

Intelligent packaging technologies are rapidly gaining interest in the agriculture and food industries. Intelligent packaging for agricultural and food products has great potential to improve the shelf life and safety of agricultural and food products apart from its basic functions of keeping the products clean and protecting against unwanted physical and chemical changes. Intelligent packaging components are not limited to radio frequency identification (RFID) sensors, time-temperature indicators, ripeness indicators, and biosensors. Carbon dioxide, oxygen gas sensors and nanobiosensor can be used for real-time monitoring of freshness or quality for agricultural and food products. In this review, details of different sensors that are primarily used for carbon dioxide or oxygen gas sensing and their possible potential to be incorporated into agricultural and food packaging for product quality monitoring are discussed. In addition, special emphasis is placed on detailing the importance of analytical signals and their transformation, because these aspects play crucial role in monitoring the quality and freshness of agricultural and food products via intelligent packaging systems. Signal transducers contribute to the establishment of communication between the product quality sensor and the communication components such as RFID sensors in smart packaging systems by converting a signal in one form of energy to another form.