Changes in SPME-extracted volatile compounds from Iberian ham during ripening

Abstract

PALABRAS CLAVES: Compuestos volátiles -JamónIbérico -Microextracción en fase sólida -Sistema de alimentación -SPME -Tiempo de curación. SUMMARYChanges in SPME-extracted volatile compounds from Iberian ham during ripening.A headspace SPME procedure was tested to study the evolution of volatile compounds during the ripening of Iberian hams from pigs reared in a Montanera system (outdoorbased, with acorn and pasture available) and a HO-Pienso system (indoor-based, with a high oleic acid concentrate). The effect of the ripening time on volatile compounds was more marked than the effect of feeding system. Most volatile compounds affected by the ripening time were compounds that come from Strecker and Maillard reactions, which increased significantly (p Ͻ 0.05) during the ripening time. This trend was clear for the volatile compounds 2-methylpropanal, 2-methylbutanal, 2-methy-l-butanol, disulfide dimethyl, 2,6-dimethylpyrazine ϩ dihidro-2(3H) furanone and benzenemethanol and, therefore they could be used as indicators of the ripening time. Conversely, some of the lipid oxidation-derived compounds decreased significantly throughout ham processing. Feeding system had a weak effect on volatile compounds, but it was significant for some compounds (p Ͻ 0.05). Some of them (butanoic acid, 2,6-dimethylpirazyne and 1-octen-3-ol) were more abundant in Montanera than in Pienso hams. These small differences could be important because they involve compounds that have been identified as Iberian ham odorants.

Analysis of volatile compounds from Iberian hams: a review

“…As can be observed, helium is the most commonly used carrier gas, but according to the van Deemter equation, hydrogen is better since the chromatographic column has better efficiency when the molecular weight of the carrier gas is lower (van Deemter et al, 1956). Several oven temperature programs have been employed, starting at 30 °C (lópez et al, 1992), 35 °C (Sabio et al, 1998;Carrapiso et al, 2002;Timón et al, 2002;Timón et al, 1998;Timón et al, 2001) or 40 °C (Ramírez and Cava, 2007;Narváez-Rivas et al, 2010b;Sánchez-Peña et al, 2005;Andrés et al, 2007;García et al, 1991;Jurado et al, 2009;García-González et al, 2008, Narváez-Rivas et al, 2010aRuiz et al, 2001;Andrés et al, 2002;Andrade et al, 2009) and increasing up to 175 °C (Sabio et al, 1998), 180 °C (lópez et al, 1992), 200 °C (Sánchez-Peña et al, 2005Andrés et al, 2007;García-González et al, 2008;28), 220 °C (Narváez-Rivas et al, 2010a, 2010b), 230 °C (Timón et al, 1998, 240 °C (García et al, 1991) or 250 °C (Ramírez and Cava, 2007;Carrapiso et al, 2002;Timón et al, 2002;Jurado et al, 2009;Timón et al, 2001;Ruiz et al, 2001;Andrade et al, 2009). Splitless mode injection is the most widely used by authors who study the volatile compounds of Iberian ham, but the split injection mode has also been used although only by Narváez-...…”

“…In some cases, a cylindrical stainless steel tool was used to extract a sample along the thickness and this was then cut into small slices (Sánchez-Peña et al, 2005) or ground (Jurado et al, 2009). Several authors have carried out the analysis by cutting a portion of ham (muscle, fat or muscle and fat), which was blended and minced (Sabio et al, 1998;Ramírez and Cava, 2007;Carrapiso et al, 2002;Narváez-Rivas et al, 2011;lópez et al, 1992;Timón et al, 1998;García et al, 1991;García-González et al, 2008).…”

“…The adsorption SPME technique, developed by Arthur et al (1990Arthur et al ( , 1992, is one of the most commonly used techniques to isolate volatiles from Iberian hams (Ramírez and Cava, 2007;Toldrá, 1998;Sánchez-Peña et al, 2005;Andrés et al, 2007;Jurado et al, 2009;García-González et al, 2008;Ruiz et al, 2001;Andrés et al, 2002;Andrade et al, 2009;zhang and Pawliszyn, 1993), since it is solvent free, inexpensive, easy to use and relatively fast (Andrade et al, 2009). SPME involves absorbing the analyte from the sample onto a modified solid support (fiber).…”

“…Several authors (Sabio et al, 1998;Ramírez and Cava, Carrapiso et al, 2002;Timón et al, 1998) have used bicep femoris muscle for this analysis. others (García et al, 1991;Jurado et al, 2009) used semi-membranosous and bicep femoris muscles. García-González et al (2008) and Sánchez-Peña et al (2005) analyzed the part located along and behind the femur, composed essentially of subcutaneous fat and bicep femoris, semi-membranosous and semitendinosous muscles.…”

“…when the process is completed, the fiber is inserted into the injector port of the gas chromatograph and the analytes are then desorbed by thermal means. The fibers chosen for the analysis of volatiles from Iberian hams are coated with divinylbenzene-carboxen-poly(dimethylsiloxane) (DvB/CAR/PDMS) (Ramírez and Cava, 2007;Sánchez-Peña et al, 2005;García-González et al, 2008) or carboxen-poly(dimethylsiloxane) (CAR/ PDMS) (Andrés et al, 2007;Jurado et al, 2009;Ruiz et al, 2001;Andrés et al, 2002;Andrade et al, 2009), because of their high sensitivity and varying thicknesses of the fiber used, which have been measured at 50/30 (Ramírez and Cava, 2007;Sánchez-Peña et al, 2005), 75 (Andrés et al, 2007;Jurado et al, 2009;Ruiz et al, 2001) and 100 µm (Andrade et al, 2009). A higher number of volatile compounds was found using CAR/PDMS as fiber (between 61 and 107 volatiles), but there is no relation between the thickness of the fiber and the number of volatiles and the highest number of volatiles (107 compounds) was found when using a thickness of 75 µm (Andrés et al, 2002) and the lowest (30 compounds) was found with a thickness of 50/30 µm (Sánchez-Peña et al, 2005).…”