Fast, Accurate Sensor To Detect Food Spoilage

In the study, John Lavigne and colleagues describe the need for better sensors that can detect food spoilage caused by E. coli, Salmonella, and other disease-causing bacteria. Existing methods, such as "electronic noses" and "electronic tongues," require expensive equipment, are time consuming and involve complicated analyses.

In the study, they describe development of a polymer material that raises a red flag, changing color in the presence biogenic amines, compounds produced by the bacterial decay of food proteins. In laboratory tests, the polymer identified and distinguished between 22 different kinds of key food-spoilage amines with 97 percent accuracy.

Researchers also used the polymer to check the freshness of a tuna by detecting the amount of amines present in the sample. "The sensitivity of the described assay is better than the typical mammalian sense of smell and is able to detect this nonvolatile amine at hazardous levels before the fish would begin to smell rancid," the report states. The approach also shows promise for detecting spoilage in other food types, it adds.

The article "A Food Freshness Sensor Using the Multistate Response from Analyte-Induced Aggregation of a Cross-Reactive Poly(thiophene)" is scheduled for the Aug. 16 issue of ACS' Organic Letters.