Teflon covers and a 75-mm carboxen/polydimethylsiloxane fiber were purchased from Supelco Inc.
Before initial use, the fiber was preconditioned for 2 h on an Agilent 6890-5975 gas chromatograph at an injector temperature of 230 _C.
Then,below 1.5 cm square of minced samples for non-fermented pork jerky and fermented pork jerky (3 g) were respectively placed in a 15-mL vial at room temperature, and the vial was sealed with a Teflon cover, heated at 60 _C in a water bath for 30 min, and mixed at intervals.
The HS-SPME fiber was inserted for sampling for 40 min, which was adequate to extract the volatile compounds from the samples and introduce them into the GCeMS injector for desorption for 5 min.