Influence of the type of fiber coating and extraction time on foal dry-cured loin volatile compounds extracted by solid-phase microextraction (SPME)

Extraction of dry-cured loin volatile compounds by solid-phase microextraction (SPME) was optimized. Two different fiber coatings: carboxen/polydimethylsiloxane (CAR/PDMS) and divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS), and three extraction times (15, 30 and 45 min) were assayed. Between the fibers tested, CAR/PDMS coated fibers extracted between two and three times more total amount of volatile compounds than the DVD/CAR/PDMS coating (1314 × 106 vs. 526 × 106 area units). Fifty five compounds were extracted by the CAR/PDMS fiber, while only 48 of these were found with the DVB/CAR/PDMS fiber. On the other hand, 6 additional volatile compounds were extracted by the CAR/PDMS coating, all of them being of low molecular weight. Three of the major compounds extracted, hexanoic acid, methyl ester; butanoic acid, 3-methyl-, methyl ester and hexanal, were found in high proportion in both fiber coatings. The effect of exposure time was more marked for the DVD/CAR/PDMS fiber than for the CAR/PDMS coating. Fifteen minutes of extraction provided a volatile compounds profile with lower area counts for most compounds and significantly different to that obtained with 30 and 45 min of extraction. The extraction yields of dry-cured loin volatile compounds varied according to the fiber coating used and the time of exposure. Therefore, extraction conditions should be selected depending on the objective of the study. Finally, it can be concluded that both porous fibers tested, CAR/PDMS and DVB/CAR/PDMS, provide a similar volatile compounds profile for dry-cured foal loin.