Kinetics of browning, phenolics, and 5-hydroxymethylfurfural in commercial sparkling wines.

We analyzed the degree of browning (absorbance at 420 nm), the phenolics, and the 5-hydroxymethylfurfural (5-HMF) content in six sparkling wines series kept at three temperatures (4, 16, and 20 °C) for over 2 years. Caffeic acid, trans-coutaric acid, p-coumaric acid, and 5-HMF were the compounds with the greatest correlation with browning and time. 5-HMF was the only compound that evolved linearly at all temperatures. We propose that 5-HMF is a better time-temperature marker than the A420 parameter or phenolics, because it shows higher linearity with time at all temperatures, is more sensitive to temperature changes, and has lower variability. The kinetics of 5-HMF was studied showing a zero-order behavior. We propose mathematical models that wineries can use to predict the browning shelf life of their sparkling wines as a function of the storage time and temperature.

Identification of 5-hydroxymethyl-2-furfural (5-HMF) in Cava sparkling wines by LC-DAD-MS/MS and NMR spectrometry.

The aim of this study was to elucidate the structure of a potential ageing marker for Cava sparkling wine. In order to clarify the structure of this compound, NMR spectroscopy and hyphenated UHPLC-DAD-MS/MS techniques were used. We identified the hitherto unknown compound as 5-hydroxymethyl-2-furfuraldehyde (5-HMF). This is the first time that this compound has been reported in sparkling wines. A survey, based on the analysis of 80 commercial sparkling wines, showed that 5-HMF is present between 0.25 and 12.81 mg/L, and is compared with those reported for other types of wine. Hypothetical origin of 5-HMF in Cava sparkling wine is discussed.

Sensory characterization of dry gins with different volatile profiles.

The aim of this study was the sensory characterization of dry gins in relation to their chemical volatile composition. The development of a specific vocabulary was necessary as a basis for quality control and to ensure the brand flavor integrity. The lexicon was obtained according to ISO 11035 (1994), on the basis of discussions between the panelists and the panel leader, reference materials, and an aroma wheel. Ten notes of the preliminary vocabulary were reduced by calculating the geometric mean (M) and applying ANOVA and principal component analysis. Finally, juniper, citric, aniseed, spice, and licorice were applied to describe 4 London Dry Gins (G1 to G4) and 2 gins with geographic indications (G5 and G6) by generic descriptive analysis (GDA). The latter were characterized by citric and juniper notes, respectively, while G 1 was characterized by spice and aniseed attributes. Licorice was uniform in all of the samples. Chemical volatile composition of samples obtained by headspace-solid phase microextraction (HS-SPME) coupled with gas chromatography/mass spectrometry (GC/MS) was in agreement with the sensory results.

Foam aptitude of trepat and monastrell red varieties in cava elaboration. 1. Base wine characteristics.

The foam properties of base wines made from red autochthonous varieties (Trepat and Monastrell) were studied. Four wines of each variety were elaborated (fermented off skins at industrial scale in two consecutive harvests) and blended at different proportions with the white traditional variety (Macabeo, Xarel.lo, and Parellada) wines to elaborate Cava (closed-bottle-fermented sparkling wine). When crescent amounts of Trepat were added to the traditional white blend, the foamability and the color intensity (CI) of the wine increased polinomically. The increase of the CI depended on the year of harvest. Thus, oenologists could decide the blend proportion most suitable to elaborate either a "blanc de noirs" sparkling wine or a new type of Cava.

Foam aptitude of trepat and monastrell red varieties in cava elaboration. 2. Second fermentation and aging.

The foam properties of sparkling wines (Cava) made from two red autochthonous grape varieties, Trepat and Monastrell, and coupages, including different percentages of them, were studied during second fermentation and aging. The effect of second fermentation on foam gave the highest decreases when the base wines had the highest foam values, while gave the lowest decreases or even increases for the base wines with the lowest foam characteristics. However, the greater the HM and Sigma of the base wine, the greater the foam values of the sparkling wine. Base wine determinations for quality control in cellars could provide information about future sparkling wine foaming. Acidity parameters, ethanol, sulfur, and polysaccharides contents were correlated to foam characteristics in the sparkling wines. In terms of color and foaming, wines made from the red varieties Trepat and Monastrell blended with white variety wines could be appropriate for elaborating "blanc de noirs" sparkling wines.

Influence of yield and maturation index on polysaccharides and other compounds of grape juice.

Wine producers may attempt to increase vine productivity, which usually decreases the quality. The quality of Cava (Spanish sparkling wine; Certified Brand of Origin in Spain) mainly depends on the composition of its colloids, which also determine foam quality. The yield (kg of grape/ha) and maturation index (ratio between soluble solids and titratable acidity) are two external factors that may alter grape characteristics, especially its composition. Twenty white grapes of the same variety (Parellada), but different yields (between 6000 and 17,000 kg/ha) were studied. By PCA, two grape groups were separated according to yield (<10,500 and >10,500 kg/ha). Yield and maturation index were not significantly correlated. Grapes obtained with yield >10,500 kg/ha had significantly higher content of soluble proteins and lower content of total polysaccharides and some polysaccharides fractions (M(r) 62,000-48,000, M(r) 28,000-24,000, and M(r) 7000-5000) than the grapes of the low-yield group (<10 500 kg/ha). Thus, it may be interesting to monitor yield, below 10 500 kg/ha, in vines used to produce Cava.

A flavonoid-rich diet increases nitric oxide production in rat aorta.

1. Red wine intake is associated with a low risk of cardiovascular disease. This effect has been partly attributed to the action of polyphenolic compounds, which decrease the oxidation of plasma low density lipoproteins. Moreover, nitric oxide ((*)NO) is a vasodilator and polyphenolic compounds induce endothelium-dependent vasorelaxation in vitro. 2. Here we studied whether a diet rich in dealcoholated red wine (DRW) increases acetylcholine-induced vasorelaxation and whether ingestion of DRW-, quercetin- or catechin-rich diets modifies the (*)NO-cyclic guanosine-3',5'-monophosphate (cyclic GMP) pathway and superoxide anion (O2(.-)) release in aorta in a resting state in rats fed semi-purified diets containing either 35% (v w(-1)) DRW, 0.3% (w w(-1)) quercetin or 0.3% (w w(-1)) catechin for 10 days. 3. (*)NO-mediated vasorelaxation induced by acetylcholine was greater in rats fed the DRW-rich diet than in those that received the control diet. 4. Expression of endothelial (*)NO synthase (eNOS) was similar in the four dietary groups. The aortic rings of rats fed either the DRW-, quercetin-, or catechin-rich diets showed higher NOS activity, (*)NO production and cyclic GMP content than those of rats fed the control diet. No changes were observed in O2(.-) production. 5. In summary, diets rich in either DRW, quercetin or catechin induced endothelium-dependent vasorelaxation in rat aorta in a resting state through the enhancement of (*)NO production, without modifying O2(.-) generation, thus the bioavailability of (*)NO was increased. The increase in the (*)NO-cyclic GMP pathway explains the beneficial effect of flavonoids at vascular level.

Prediction of wine foaming.

A procedure for estimating the foam properties of sparkling base wines without specifically measuring foam was developed. This method was based on mathematical equations established between the usual parameters of wine quality control (independent variables of the equations) and the wine foam parameters [foamability (HM), Bikerman coefficient (Sigma), and surface tension (ST)] obtained with the specific equipment (dependent variables of the equations). Ninety-six white wines from the Cava region produced at industrial scale were used to establish these equations. Two predictive equations that could be applied to different types of wine from different origins were obtained: one to predict the foamability (HM) and the other to predict the Bikerman coefficient (Sigma). Moreover, the database of foam parameters of the 96 wines allowed a qualitative assessment of wine foaming values.

Whole blood and serum copper levels in relation to sex and age.

The copper content in whole blood and serum was determined in healthy human subjects (240 males and 217 females) by atomic absorption spectrophotometry. The mean level of copper obtained in whole blood was 104.8 +/- 20.5 micrograms/100 ml in males and 117.1 +/- 20.1 micrograms/100 ml in females. The mean level of copper in serum was 102.3 +/- 21.7 micrograms/100 ml and 123.9 +/- 30.4 micrograms/100 ml, in males and females respectively. The copper concentration in whole blood and serum in females proved to be significantly higher than in males (p less than 0.001). With respect to age, the copper level showed a slightly negative correlation which is only statistically significant in whole blood in females (p less than 0.05).

Whole blood and serum zinc levels in relation to sex and age.

The zinc content in whole blood and serum was determined in 239 healthy males and 217 healthy females by atomic absorption spectrophotometry. The mean level of zinc obtained in whole human blood from males was 607.0 +/- 105.3 micrograms/100 ml and in females 585.2 +/- 122.9 micrograms/100 ml. The mean level of zinc in serum was 116.6 +/- 55.2 micrograms/100 ml and 105.2 +/- 66.9 micrograms/100 ml in males and females respectively. The zinc concentration in whole blood and serum in males proved to be slightly higher than in females though the difference is not statistically significant. For the males a positive correlation was found between age and the zinc level in whole blood and serum; this is only statistically significant in whole blood. In females, the zinc level in whole blood showed a positive correlation with age which was not statistically significant, while in serum this correlation was negative and statistically significant.