Monitoring of volatile production in cooked poultry products using selected ion flow tube-mass spectrometry

Cooked poultry products are nutritious and economically valuable products that are at risk of bacterial spoilage, which can be postponed by cooling and modified-atmosphere-packaging (MAP). In this study, a cooked chicken product was stored at three different temperature ranges (4–6 °C, 7–9 °C, and 11–13 °C) and volatile production was measured over time using selected ion flow tube-mass spectrometry (SIFT-MS). The identities of the volatiles formed were confirmed by headspace solid-phase microextraction coupled with gas chromatography time-of-flight mass spectrometry (HS-SPME-GC-TOF-MS) analysis. In total, 33 volatiles were proposed using the latter technique and their concentrations were calculated using product ion counts after assignment of these counts to specific volatiles. The results indicated that 1-octen-3-ol, 2,3-butanediol, acetoin, benzaldehyde, ethanol, methylbutanal, and methylbutanol may serve as biomarkers for bacterial growth and/or chemical degradation of cooked poultry products. In parallel, the bacterial loads of the product samples were determined on selective agar media. A total of 495 bacterial isolates was classified and identified by (GTG)5-PCR fingerprinting, followed by gene sequencing of representative cluster isolates. Carnobacterium divergens, Carnobacterium maltaromaticum, Rahnella aquatilis, and Serratia proteamaculans were the most commonly found species, besides minor contributions of Lactobacillus sakei and Hafnia alvei. Differences in volatile profiles could thus be ascribed to variations in bacterial loads and storage temperatures.