Detection of rancidity in freeze stored turkey meat using a commercial gas-sensor array system

Rancidity has been investigated with a commercial solid state based gas-sensor array system in freeze stored turkey stored at two different temperatures, −10 and −20 °C and different atmospheric conditions, respectively in presence of air and under vacuum. Samples were kept stored up to 9 months and analyzed at different times during storage. The gas-sensor readings showed high correlation with reference measurement data as TBARS, secondary volatile oxidation products, and rancidity related sensory attributes (r > 0.9, p < 0.001). It could be demonstrated that the gas-sensor based method had a similar ability as a trained sensory panel to detect lipid oxidation in freeze stored turkey meat. For samples stored in vacuum or at −10 °C a better discrimination was obtained with the gas-sensor array system. It was possible by means of selected sensor readings to obtain a complete discrimination between the samples stored in air at −10 and −20 °C, and vacuum and air stored samples from −20 °C, respectively. The performance of the gas-sensor array system with regard to the prediction of rancid odour and flavour was confirmed by GC/MS analysis showing that the major volatile compounds where also the lipid oxidation derived products representing the key rancid odour compounds. The results suggest that solid state based gas-sensor arrays could be an alternative rapid method to detect and quantify lipid oxidation in freeze stored poultry products.