Moscatel vine-shoot extracts as a grapevine biostimulant to enhance wine quality.

Non-aromatic vine-shoot extracts (Airén) has been recently proposed as "viticultural biostimulants" when applied to grapevine. In this paper, the application of extracts from non-toasted (MVS) and toasted (MVSToasted) vine-shoots from the well-known aromatic variety such Moscatel were applied on Airén grapevine leaves, observing an increased for grape yield and wines with a lower alcohol degree. All wines at the end of the alcoholic fermentation were characterized by their fruity and floral descriptors, especially MVS wines; and 4 months later, MSV and MVSToasted wines surprised by their higher spicy notes, which correspond with the highest OAVs values for compounds such as norisoprenoids (ß-damascenone), vanillin derivatives (vanillin, acetovanillone) and volatile phenols (guaiacol, syringol), compared to control wine. Wine phenolic composition was affected positively over all by MVS in case of phenolic acids. These results confirm that Moscatel vine-shoot extracts foliar application into Airén non-aromatic grapevines produce an interesting enhance on wine quality.

Effect of toasting on non-volatile and volatile vine-shoots low molecular weight phenolic compounds.

Low molecular weight phenolic compounds (LMWPC), including non-volatile and volatile, of Airén and Moscatel vine-shoot cultivars waste submitted to different toasting conditions (light, 180°/15min; medium, 180°/30min; high 180°/45min) were studied in order to exploit them with oenological purposes. The LMWPC differences were mainly due to the toasting times rather than vine-shoot variety. In non-volatile LMWPC fraction, flavanols and almost all phenolic acids decreased by toasting. The presence of trans-resveratrol has a special relevance at light toasting: 14 times more concentrated in Airén and 6 times in Moscatel vine-shoots, than their respective non-toasted samples. The volatile LMWPC showed a significant increment with toasting, being vanillin the one with the highest difference respect to non-toasted samples at high conditions: more than 15 times in Airén and 11 in Moscatel. Although toasting reduced some LMWPC, particular characteristics of these vine-shoots must be taken into account when considering its future use.

Vine-shoot waste aqueous extract applied as foliar fertilizer to grapevines: Effect on amino acids and fermentative volatile content.

The aim of this work was to study the influence of foliar applications of different wood aqueous extracts on the amino acid content of musts and wines from Airén variety; and to study their relationship with the volatile compounds formed during alcoholic fermentation. For this purpose, the foliar treatments proposed were a vine-shoot aqueous extract applied in one and two times, and an oak extract which was only applied once. Results obtained show the potential of Airén vine-shoot waste aqueous extracts to be used as foliar fertilizer, enhancing the wine amino acid content especially when they were applied once. Similar results were observed with the aqueous oak extract. Regarding wine fermentative volatile compounds, there is a close relationship between musts and their wines amino acid content allowing us to discuss about the role of proline during the alcoholic fermentation and the generation of certain volatiles.

Effect of vine foliar treatments on the varietal aroma of Monastrell wines.

The effects of four vine treatments, comprising the application of eugenol and guaiacol (individually or as a mixture) or whiskey lactones on the concentration of glycosidically bound aroma precursors, determined as glycosyl glucose content by HPLC-IR, in Monastrell grapes and their wines were studied. The impact of treatments on the free varietal wine aroma determined by SBSE-GC-MS and descriptive analysis after alcoholic and malolactic fermentations and six months of ageing were also determined. A synergistic effect was observed between the eugenol and guaiacol on the glycosidically bound aroma precursor fraction. The rate of release of such aroma precursors was time and treatment dependent. The impact on wines varietal aroma at the end of the alcoholic fermentation was reduced by treatments, whereas the opposite effect was observed in the following samplings. At a sensory level, the wood/oak notes were appreciated in all wines; however, the typicity of the Monastrell variety was especially enhanced at the end of the malolactic fermentation, in the wines from whiskey lactone treatment.

Potential application of aromatic plant extracts to prevent cheese blowing.

This study aimed to inhibit the growth of Escherichia coli and Clostridium tyrobutyricum, common bacteria responsible for early and late cheese blowing defects respectively, by using novel aqueous extracts obtained by dynamic solid-liquid extraction and essential oils obtained by solvent free microwave extraction from 12 aromatic plants. In terms of antibacterial activity, a total of 13 extracts inhibited one of the two bacteria, and only two essential oils, Lavandula angustifolia Mill. and Lavandula hybrida, inhibited both. Four aqueous extracts were capable of inhibiting C. tyrobutyricum, but none were effective against E. coli. After extracts' chemical composition identification, relationship between the identified compounds and their antibacterial activity were performed by partial least square regression models revealing that compounds such as 1,8 cineole, linalool, linalyl acetate, ß-phellandrene or verbene (present in essential oils), pinocarvone, pinocamphone or coumaric acid derivate (in aqueous extracts) were compounds highly correlated to the antibacterial activity.

Characterization of the antimicrobial susceptibility of fungi responsible for onychomycosis in Spain.

Due to the increase of choices relative to antifungals, there is a need to improve the standardization of in vitro methods used to determine the antifungal susceptibility of fungal pathogens. Our study evaluated the in vitro susceptibility of filamentous fungi isolated from patients with toenail onychomycosis against itraconazole, ciclopirox, eberconazole, fluconazole and terbinafine. The minimum inhibitory concentration (MIC) of these antifungal agents was determined with 100 isolates, including dermatophytes (70 strains) and non-dermatophyte molds (30 strains). The susceptibility of fungal isolates was measured by using a technique modified for dermatophytes (0.5 × 10(3)-0.5 × 10(4) conidia/ml as inocula) which followed the procedures described by the Antifungal Susceptibility Testing Subcommittee of the European Committee on Antimicrobial Susceptibility Testing (AFST-EUCAST) and the Clinical and Laboratory Standard Institute (CLSI M38-A). MIC ranges were 0.016-8.0 µg/ml for itraconazole, ciclopirox and eberconazole, 0.063-32.0 µg/ml for fluonazole, and 0.004-2.0 µg/ml for terbinafine. In vitro susceptibility tests indicated that eberconazole has a broad antimicrobial profile, including dermatophytes, as well as other filamentous fungi. Terbinafine was active (0.016-0.250 µg/ml) against dermatophytes.

Haloanisole and halophenol contamination in Spanish aged red wines.

This is the first study to be carried out on the incidence of halophenols and haloanisoles, including trichloroanisole, in aged red wines. A total of 966 red wines, aged for 6, 12 and 24 months in oak barrels and from different Spanish production areas, were analysed by stir bar sorptive extraction followed by gas chromatography/mass spectrometry (GC/MS). From the wines sampled, 155 (16.1%) were contaminated with one or several compounds, with 7.6, 6.9 and 1.5% corresponding to the 12- (aged-12), 6- (aged-6) and 24-month-aged (aged-24) wines, respectively. The most abundant compounds causing taint were 2,3,4,6-tetrachloroanisole and 2,4,6-trichloroanisol (6.8 and 5.3%, respectively). No 2,4,6-tribromophenol was found in any of the samples. Contamination with halo compounds was highest in samples from South-West Spain, followed by those from Northern Spain. The mean concentration for all compounds were always higher than their respective olfactory threshold, but none of these halo compounds represent a health hazard to humans through the consumption of commercial red aged wines.

A new approach to saffron aroma.

The aroma of saffron has received much attention from scientists in recent years, not only for the compounds that make it up, but also for its glycosidic precursors. Despite it all, the volatile generation mechanisms of the spice are almost completely unknown. Only the generation of safranal, the major compound, from picrocrocin has been established. The great effort carried out to detect and identify the volatile compounds of saffron has not been enough to clarify which compounds are responsible for saffron aroma. In general, scientists has devoted little attention to the sample analyzed, taking for granted that all saffron is the same, something that makes it difficult to establish a comparison between the results obtained by the different authors, to the point that saffron aroma has not been defined yet. It must be clarified whether saffron aroma is what the consumer perceives via nasally when a container of the spice is uncovered, or whether on the contrary, it is the aroma conferred to food, normally after a thermal cooking process, and perceived retronasally. After an extensive bibliographic research, simple assays are suggested to understand what could be considered as saffron aroma, results that may help to delimit the research for future studies.

Analysis of wine primary aroma compounds by stir bar sorptive extraction.

Due to the great importance of some primary aroma compounds on wine quality, these compounds which includes terpenes, C(13)-norisoprenoids and C(6) compounds, have been analyzed by stir bar sorptive extraction (SBSE) followed by a thermal desorption-gas chromatography-mass spectrometry analysis. The stir bar sorptive extraction method was optimized in terms of temperature, time, pH and NaCl addition. The best SBSE sorption kinetics for the target analytes were obtained after submitting the solutions to 60 degrees C during 90min. The addition of sodium chloride did not enhance the volatile extraction. The method proposed showed good linearity over the concentration range tested, with correlation coefficients higher than 0.98 for all the analytes. The reproducibility and repeatability of the method was estimated between 0.22 and 9.11%. The detection and quantification limits of all analytes were lower than their respective olfactory threshold values. The application of this SBSE method revealed that monovarietal white wines were clearly separated by two canonic discriminating functions when grape varieties were used as differentiating variable, the first of which explained 98.4% of the variance. The compounds which contributed most to the differentiation were limonene, linalool, nerolidol and 1-hexanol.

Stir bar sorptive extraction for the determination of volatile compounds in oak-aged wines.

Stir bar sorptive extraction (SBSE) followed by a thermal desorption-gas chromatography-mass spectrometry analysis has been optimized for the determination of 13 of the most important oak volatiles in wine samples, all in a single run. The stir bar sorptive extraction method was optimized in terms of temperature, time, pH and NaCl addition, and the best results were obtained after stirring the wine sample with the polydimethylsiloxane stir bar during 90min at room temperature. The addition of sodium chloride did not enhance the volatile extraction. The method proposed showed good linearity over the concentration range tested, with correlation coefficients ranging from 0.92 to 0.99 for all the analytes. The reproducibility and repeatability of the method was estimated between 0.11 and 5.45%. The detection and quantification limits of all analytes were lower than their respective olfactory threshold values, and, most importantly, no artifacts have been observed during the analysis as described in most extractions using other current methodologies.

Screening method for the detection of artificial colours in saffron using derivative UV-Vis spectrometry after precipitation of crocetin.

A screening method for the detection of artificial colours (naphthol yellow, tartrazine, quinoline yellow, Sunset yellow, Allura red, amaranth, azorubine, Ponceau 4R and Red 2G) in saffron is described. The method involves removal of crocins by precipitation of crocetin (pH 0.1, 90 degrees C) before adsorption of the artificial colours on polyamide SPE cartridges (pH 2). After washing with methanol, acetone and methanol, elution was done with a methanol:ammonia solution (95:5 v/v), and detection was performed by derivative spectrometry. Sample pretreatment changes the UV-Vis saffron extract profile in such a way that second derivative spectra can be used to identify the presence of added colours. Erythrosine, which was found to be pH dependent, could not be detected under the above conditions. The lowest detectable amount for each colour was strongly dependent on chemical structure. The recovery of carminic acid was very low possibly due to irreversible retention on the polyamide. This procedure can replace the current ISO TLC method (2003) and be used alternatively or in combination with HPLC procedures adopted in the same standard.

Stir bar sorptive extraction for the analysis of wine cork taint.

A magnetic stir bar with a polydimethylsiloxane coating was used to absorb 2,4,6-trichloroanisole, 2,3,4,5-tetrachloroanisole, pentachloroanisole and their respective phenols from synthetic and real wine samples. The stir bar sorptive extraction method was optimised to obtain the best extraction conditions in terms of temperature, time, pH and NaCl addition. The stir bar was desorbed in a thermal desorption system coupled to a gas chromatograph-mass spectrometer. The method proposed showed good linearity over the concentration range tested and correlation coefficients ranged from 0.96 to 0.99 for all the analytes. The reproducibility and repeatability of the method was estimated between 1.29 and 4.02%. With no a pre-concentration step and with a much reduced analysis time, all the analyzed compounds showed detection and quantification limits that were lower than those observed with other methods found in the bibliography. Except for pentachlorophenol due to its poor absorptivity in polydimethysiloxane, in red wines, LOD ranged between 7.56 and 61.56 pg/l, and LOQ ranged between 17.21 and 205.11 pg/l; while in white wines, the LOD ranged between 5.82 and 30.50 pg/l and LOQ ranged between 19.41 and 101.61 pg/l. These concentrations were always lower than their respective olfactory thresholds values.