Identification of the aroma compounds in stinky mandarin fish (Siniperca chuatsi) and comparison of volatiles during fermentation and storage

Identification of aroma compounds in Stinky Mandarin fish (Siniperca chuatsi) and comparison of volatiles during fermentation (with spices and salt) and storage were analysed by electronic nose (e-nose) combining with gas chromatography-mass spectrometry (GC-MS). Among the sixty-one detected volatiles, thirteen aroma-active compounds, especially linalool, were identified in stinky mandarin fish according to thresholds and concentrations. Totally, twenty-four aroma compounds correlated well with the periods of fermentation and storage. Trimethylamine, indole, sulphur-containing compounds, acetic acid, esters and phenols increased continually, while aldehydes decreased. According to these quality indicators, e-nose data using principal component analysis showed a clear discrimination of the fermented fish and were in good agreement with the results of GC-MS. In conclusion, fermentation favoured to retard spoilage and provided new aroma compounds. The technique employing an e-nose in combination with GC-MS could compare and identify the aroma and quality of stinky mandarin fish.