Advances in food spoilage detection through gas sensing: From material insights to prospects for commercialisation

Food spoilage poses a significant threat to global food security, public health, and economic sustainability, emphasising the need for quick and reliable spoilage detection sensors. Conventional detection techniques, such as microbiological assays and chromatographic methods, are often lengthy and require extensive laboratory procedures, making them unsuitable for on-site food quality assessment. During the spoilage and ripening processes, various gaseous, volatile organic compounds, and biogenic amines are emitted, serving as key indicators of food safety and quality. Gas sensors have gained increasing demand for their ability to detect these markers in real-time, owing to their quick response, high sensitivity, and cost-effectiveness. This review provides a comprehensive analysis of gas-sensing systems for food spoilage detection. It begins by introducing the key spoilage-related gases, volatile organic compounds, and biogenic amines produced in the food sector, followed by a brief discussion of traditional detection approaches. Furthermore, the operating principles of resistive and electrochemical sensors are crucial in understanding the gas sensing mechanisms, especially with nanostructured sensing materials, including metal oxides, conducting polymers, carbon-based nanomaterials, and metal nanocomposites. These nanomaterials have unique physicochemical properties that improve selectivity, sensitivity, and response time, thus enhancing sensing performance due to their high surface area, rapid charge transport, and tunable electronic properties. Somewhat uniquely, a dedicated concluding section outlines the status of commercialisation of food spoilage sensors, particularly of interest to entrepreneurs and industry stakeholders. In conclusion, this work aims to bridge material innovation with practical sensing needs in guiding the development of next-generation gas sensors for high-performance, intelligent, real-time, market-ready solutions for food quality monitoring.