A polypyrrole based gas sensor for detection of volatile organic compounds (VOCs) produced from a wheat bread

Early detection of contamination in food items is the current interest of research. Changes in concentration of volatile organic compounds emitted by the food items can provide valuable information about its contamination. Hence, a polypyrrole based gas sensor is developed for the detection and monitoring the organic volatiles produced from wheat bread during storage. Gas chromatography-mass spectroscopy results show that 1-heptanol, 1-pentanol, 1-octanol are the predominant volatiles produced from wheat bread during storage. Multifrequency impedance measurement technique is used to monitor the changes in electrical properties, mainly capacitance of the developed sensor over a frequency range 10 Hz-2 MHz upon exposure to the above organic volatiles produced from the bread during storage of 120 h. Electrical property data show that the quantitative change in the above volatiles has influence on the change in capacitance of the developed sensor. © 2011 Springer Science+Business Media, LLC.