Different Diacetyl Perception Detected through MOX Sensors in Real-Time Analysis of Beer Samples

Beer is the most consumed alcoholic beverage; with 177.5 million kiloliters produced every year, it is one of the most relevant food products. Diacetyl is a typical byproduct of yeast metabolism that is formed during the fermentation inside breweries. The perception of this high volatile and butter-like flavor molecule varies according to the kind of beer, from a positive and highly sought characteristic to a characteristic that is avoided. Furthermore, its toxicity when inhaled has been proven. Typical diacetyl analysis includes voltametric detection and chromatographic analysis techniques. Using metal oxide sensors (MOS), this analysis can become fast and cost-effective, evaluating the differences in diacetyl concentrations through resistance variation. The S3+ (Nano Sensor Systems s.r.l.; Reggio Emilia, Italy; device can recognize volatile compounds through a tailormade array of different materials. The results can be shown on a PCA that is directly generated by the instruments and can be used to manage the productive process through an IoT integrated system. Testing different beer typology through electrochemical sensors allows for the validation of this new approach for diacetyl evaluation. The results have shown an excellent ability to detect diacetyl in different beer samples, perfectly discriminating among different concentrations.