Influence of the ripening chamber's geographical location on dry-cured Iberian ham's key odorants.

Olfactometric and sensory analyses have been applied to study the possible influence of the ripening chamber's geographical location on the aroma sensory profiles and key odorants of Iberian ham. Dry-cured Iberian ham was obtained from 3 acorn-fed pigs and, for the first time, both of the participating production facilities, located in two different Andalusian municipalities with different altitudes above mean sea level, processed one of the two hind legs from each pig. The descriptive sensory profile of orthonasal and retronasal odours was determined by trained panellists, while odour-active compounds were determined by gas chromatography/mass spectrometry-olfactometry (GC/MS-O). The results obtained showed that, separately, both techniques enable Iberian ham samples to be differentiated by their ripening chamber's geographical location. For sensory analysis, retronasal sensory analysis appeared to be the most suitable for this goal, highlighting the "meat broth odour" and "roasted nuts odour" descriptors which presented significant differences between geographical locations for samples from all pigs. Moreover, ripening chamber's geographical location characteristics and the initial composition of the raw material seemed to influence the content of some odour-active compounds. The odour-active compound identified as octane/acetone and isobutanol were conditioned by the ripening chamber's geographical location, while decanal/2-ethyl-1-hexanol, 1-undecanol, 2-furanmethanol and cis-2-nonenal were also influenced by the individual pig itself. This study showed that slight climatological differences due to the location of the ripening chamber seem to have somewhat of an influence on the aromatic profile.

A non-destructive sampling method for food authentication using gas chromatography coupled to mass spectrometry or ion mobility spectrometry.

The study of volatile compounds obtained by gas chromatography (GC) coupled to mass spectrometry (MS) or ion mobility spectrometry (IMS) may be very useful to protect food quality, especially when using a non-destructive sampling method. In this work, the authentication of the highly appreciated dry-cured Iberian ham by those techniques was studied and compared. The results obtained show the suitability of a non-destructive sampling method coupled to headspace sampling (HS)-GC-IMS or HS-GC-MS to determine volatile markers in the feeding Iberian pig regime. Although both methods were suitable to differentiate the ham categories, HS-GC-IMS was more sensitive detecting a higher number of compounds than HS-GC-MS, which provided accurate qualitative results. The results of principal component analysis showed that ethanol, 2-propanol and 3-methylbutanol, identified by HS-GC-IMS, and 3-methylbutanal and heptane, identified by HS-GC-MS, could be considered potential markers to identify ham from different feeding regimes.

Assessment of UV-visible spectroscopy as a useful tool for determining grape-must caramel in high-quality wine and balsamic vinegars.

The addition of E-150d caramel, known as grape-must caramel in vinegars, is a legal but without limitation practice in Spanish wine vinegars, as those with a protected designation of origin (PDO), for unifying the final colour of different batches and barrels. It is also used in the production of 'Balsamic vinegar of Modena' vinegars, with a maximum addition fixed at 2% v/v by law. Although its quantification in vinegars was studied by other techniques, there is still not any official method for it. Therefore, UV-vis spectroscopy was assessed as a quick analytical method able to quantify grape-must caramel in Balsamic vinegars of Modena and Spanish PDO wine vinegars. Univariate and multivariate calibrations were assessed for this quantification. Results demonstrated the ability of UV-vis spectroscopy coupled with multivariate calibration in the quantification of grape-must caramel, predicting caramel amounts under 2% v/v in both Balsamic and PDO wine vinegars.

Sensory and spectroscopic characterization of Argentinean wine and balsamic vinegars: A comparative study with European vinegars.

In Argentina, vinegars are cheap agro-food products without exhaustive regulation and the production of high-quality vinegars has not been exploited yet. In fact, Argentinean vinegars have not been studied. In this context, a first study of Argentinean balsamic and wine vinegars was carried out by a sensory and spectroscopic characterization and by a comparison with well-recognized European vinegars. For that, ultraviolet-visible and fluorescence spectroscopies were applied together with principal component analysis (PCA) and parallel factor analysis (PARAFAC) performed on each data set, respectively. Results showed differences between acetification processes, origin countries and a wide variability within Argentinean production. The sensory characterization on Argentinean wine vinegars was performed by triangular and ordering preference tests showing statistically significant preferences toward the traditional and the rapid vinegars. This work highlights the effect of production on quality in order to provide added value to the Argentinean vinegars.

Influence of Saccharomyces cerevisiae and Lachancea thermotolerans co-inoculation on volatile profile in fermentations of a must with a high sugar content.

The aim of this work was to evaluate how the use of mixed cultures of Saccharomyces cerevisiae and Lachancea thermotolerans indigenous yeast strains influences the volatile composition of wine. Multivariate curve resolution (MCR) method has been applied to data analysis. Five fermentation trials were carried out: three co-inoculated with L. thermotolerans:S. cerevisiae, at the ratio of 50:1, 20:1 and 5:1 respectively, and two with a pure culture of each strain. A must from sun-dried Pedro Ximénez grapes was employed. Volatile composition was determined by dual sequential stir bar sorptive extraction, followed by GC-MS analysis. MCR provided 171 peaks. Results in co-inoculation fermentations revealed that the majority compounds obtained in each case followed the same trend as that observed for the pure culture of the strain that was present in a higher proportion. Finally, 50:1 and 20:1 seemed to be the best proportions to obtain a wine with a quality volatile profile.

Recent developments in the analysis of musty odour compounds in water and wine: A review.

One of the most common taints in foods is a musty or earthy odour, which is commonly associated with the activity of microorganisms. Liquid foods, particularly wine and water, can be affected by this defect due to the presence of certain aromatic organic compounds at very low concentrations (ng/L) consistent with human threshold perception levels. The volatile compounds responsible for a mouldy off-aroma include approximately 20 compounds, namely, haloanisoles, geosmin, 2-methylisoborneol, several alkyl-methoxypyrazines, 1-octen-3-ol, 1-octen-3-one, trans-octenol, 3-octanone, fenchol and fenchone. Methods for determining these very low concentrations of odour compounds must be extremely sensitive and selective with efficient preconcentration treatments. A number of extraction techniques based on LLME (liquid-liquid microextraction), SPME (solid-phase microextraction) or SBSE (stir-bar sorptive extraction) can be applied and should be selected on a case-by-case basis. Moreover, recent developments in GC instrumentation coupled to different detection systems can effectively increase the selectivity and sensitivity of the analysis of target compounds.