A cost-effective and reusable impedimetric sensing platform utilizing molecularly imprinted polymers for edible oil spoilage detection.

Volatile organic compounds (VOCs) are low-molecular-weight, high-vapor-pressure gases that readily evaporate with a distinct odor profile. In the food industry, spoilage of food products is accompanied by the release of undesirable VOCs with a rancid odor profile. Monitoring these VOCs across the farm-to-fork value chain provides crucial information on product quality and enables data-driven decision-making for consumers and stakeholders, such as logistics and cold chain operators. In particular, degradation-related VOCs in edible oils are extremely challenging to detect due to the strong masking from other aroma-related VOCs and the lack of observable visual cues. In this work, we developed a highly sensitive and specific Molecularly Imprinted Polymer (PA-MIP) functionalized VOC sensor for the detection of Pentanoic Acid. Using only a 10 mL sample volume, the PA-MIP sensor achieved a rapid response time of 5 min and a detection limit of 25 ppm for Pentanoic Acid, with at least threefold higher response compared to structurally related and fragrance-related VOCs in fragrant peanut oil. The sensor was reusable for at least ten measurement cycles without significant performance degradation and reliably discriminated artificially aged peanut oil from fresh oil. Together, these metrics position the VOC sensing system as a practical tool for real-time peanut oil freshness monitoring that strengthens food safety and helps curb food wastage.