Citric acid sensor is faster and cheaper

Citric acid is the most widely used acidulant and preservative in the world and is used in many foods, drinks and pharmaceutical preparations. Members of a photochemistry research group at the University Jaume I, Spain designed a molecule, which could have applications in the food and pharmaceutical industries. The molecule produces light in the presence of citric acid, with more emitted for higher concentrations. On of the advantages of the new sensor is its ability detect one citric acid molecule among millions of water molecules through fluorescence, the developers claim. Francisco Galindo, co-author of the research study, said another advantage is the improved fluorescence intensity. "With the complexes developed it is possible to achieve gains of up to 1500 per cent in fluorescence intensity in the presence of citrate,"​ he said. "This implies multiplying the signal by a factor of 15, which results in very reliable measurements." ​​The molecule is also designed to react with samples immediately, as opposed to the waiting time that can be up to 30 minutes with the traditional lyase enzyme method, the developers claim. "This advantage in the data acquisition speed can be very important when it comes to developing automatic real-time measurement systems, such as those required in food quality control to detect possible defects in the manufacturing quality of a given product, or in urgent medical urine or blood tests for the rapid diagnosis of diseases associated with the presence of citric acid,"​ the researchers said. The University, which has patented the technology, now expects to target the food and pharmaceutical sectors. Formulation and processing purposes require food processors to know citric acid level present in products derived from fruits such as oranges or lemons. In the pharmaceutical industry, citric acid is used as a stabiliser, as a drug component and as an anticoagulant in blood for transfusions.