Sensory and analytical study of rose sparkling wines manufactured by second fermentation in the bottle

The sensory and analytical characteristics of five rose sparkling wines manufactured by the traditional method have been determined. Moreover, the changes that take place in the nitrogen and volatile fraction of the wines during the second fermentation and the aging with the yeasts have been studied. Each of these wines was made from a single industrial rose base wine of the Garnacha Tinta variety, with five selected yeasts strains. The base wine had a low content in free amino acids, 16 mg/L, and the yeast consumed more peptides than free amino acids during second fermentation. From the application of the two-way analysis of variance, yeast strain, and aging time factors to the data of volatile compounds, it has been found that most of the differences between these sparkling wines are due to the aging time. It has been verified that these rose sparkling wines have foam of good quality and that the grape variety Garnacha Tinta is suitable for the production of rose sparkling wines.     

Polyphenols-enriched Chardonnay white wine and sparkling Pinot Noir red wine identically prevent early atherosclerosis in hamsters

The effects of a white wine enriched with polyphenols (PEWW) from Chardonnay grapes and of a sparkling red wine (SRW) from Pinot Noir and Chardonnay grapes were studied for the first time on early atherosclerosis in hamsters. Animals were fed an atherogenic diet for 12 weeks. They received by force-feeding PEWW, SRW, ethanol 12% (ETH), or water as control (mimicking a moderate consumption of approximately 2 red wine glasses per meal for a 70 kg human). Plasma cholesterol concentrations were lower in groups that consumed PEWW and SRW accompanied by an increase in the ratio apo A-1/apo B. Liver-specific activities of superoxide dismutase and catalase were significantly increased by PEWW (38 and 16%, respectively) and by SRW (48 and 15%, respectively). PEWW and ETH significantly increased plasma antioxidant capacity and vitamin A concentrations. Aortic fatty streak area (AFSA) was significantly strongly reduced in the groups receiving PEWW (85%) and SRW (89%) in comparison with the control. AFSA was reduced by ethanol to a lesser extent (58%). These data suggest that tannins from the phenolics-enriched white wine induce a protective effect against early atherosclerosis comparable to that produced by sparkling red wine containing tanins and anthocyanins and dissociated from the antioxidant action of these compounds.     

Sensory threshold of 1,1,6-trimethyl-1,2-dihydronaphthalene (TDN) and concentrations in young Riesling and non-Riesling wines

1,1,6-Trimethyl-1,2-dihydronaphthalene (TDN) is well-known to contribute "petrol" aromas to aged Riesling wines, but its prevalence and contribution to young Riesling or non-Riesling wines is not well understood. TDN concentrations were measured in 1-3-year-old varietal wines produced from Cabernet franc (n = 14 wines), Chardonnay (17), Cabernet Sauvignon (4), Gewurztraminer (4), Merlot (9), Pinot gris (6), Pinot noir (9), Riesling (28), or Sauvignon blanc (6). TDN concentrations in the Riesling wines, 6.4 ± 3.8 μg/L, were significantly higher than in all other varietals, 1.3 ± 0.8 μg/L. The odor detection thresholds for TDN were then determined in both model wine and a neutral white wine. Group sensory thresholds were found to be the same in both matrices, 2 μg/L, indicating little masking of TDN due to the odorants in the neutral white. The TDN sensory threshold was a factor of 10 below the previously reported odor threshold. On the basis of this revised threshold, 27 of 28 Riesling wines had suprathreshold TDN, whereas only 7 of 69 non-Riesling wines had suprathreshold TDN. The monoterpenes linalool and geraniol were also measured in the Riesling wines, and odor activity values (OAVs) were calculated for the monoterpenes and TDN. The OAV for TDN was higher than for the monoterpenes in 25 of 28 Riesling wines.     

Odor potency of aroma compounds in Riesling and Vidal blanc table wines and icewines by gas chromatography-olfactometry-mass spectrometry

This study aimed to elucidate the odor potency of aroma compounds in Riesling and Vidal blanc (syn. Vidal) table wines and icewines from the Niagara Peninsula using stir bar sorptive extraction-gas chromatography-olfactometry-mass spectrometry. Dilution analysis determined the most odor-potent compounds in Vidal and Riesling icewines (n = 2) and table wines (n = 2) from a commercial producer. The top 15 odor-potent compounds in each wine were identified and quantified, resulting in 23 and 24 compounds for Riesling and Vidal, respectively. The most odor-potent compounds were β-damascenone, decanal, 1-hexanol, 1-octen-3-ol, 4-vinylguaiacol, ethyl hexanoate, and ethyl 3-methylbutyrate. In general, icewines had higher concentrations of most aroma compounds compared to table wines. Through computation of odor activity values, the compounds with the highest odor activity for the icewines were β-damascenone, 1-octen-3-ol, ethyl octanoate, cis-rose oxide, and ethyl hexanoate. In table wines the highest odor activity values were found for ethyl octanoate, β-damascenone, ethyl hexanoate, cis-rose oxide, ethyl 3-methylbutyrate, and 4-vinylguaiacol. These findings provide a foundation to determine impact odorants in icewines and the effects of viticultural and enological practices on wine aroma volatile composition.     

Aroma chemical composition of red wines from different price categories and its relationship to quality

The aroma chemical composition of three sets of Spanish red wines belonging to three different price categories was studied by using an array of gas chromatographic methods. Significant differences were found in the levels of 72 aroma compounds. Expensive wines are richest in wood-related compounds, ethyl phenols, cysteinil-derived mercaptans, volatile sulfur compounds, ethyl esters of branched acids, methional, and phenylacetaldehyde and are poorest in linear and branched fatty acids, fusel alcohols, terpenols, norisoprenoids, fusel alcohol acetates, and ethyl esters of the linear fatty acids; inexpensive wines show exactly the opposite profile, being richest in E-2-nonenal, E-2-hexenal, Z-3-hexenol, acetoin, and ethyl lactate. Satisfactory models relating quality to odorant composition could be built exclusively for expensive and medium-price wines but not for the lower-price sample set in which in-mouth attributes had to be included. The models for quality reveal a common structure, but they are characteristic of a given sample set.     

Synergistic effect of high and low molecular weight molecules in the foamability and foam stability of sparkling wines

The foam of sparkling wines is a key parameter of their quality. However, the compounds that are directly involved in foam formation and stabilization are not yet completely established. In this work, seven sparkling wines were produced in Bairrada appellation (Portugal) under different conditions and their foaming properties evaluated using a Mosalux-based device. Fractionation of the sparkling wines into four independent fractions, (1) high molecular weight material, with molecular weight higher than 12 kDa (HMW), (2) hydrophilic material with molecular weigh between 1 and 12 kDa (AqIMW), (3) hydrophobic material with molecular weigh between 1 and 12 kDa (MeIMW), and (4) hydrophobic material with a molecular weight lower than 1 kDa (MeLMW), allowed the observation that the wines presenting the lower foam stability were those that presented lower amounts of the MeLMW fraction. The fraction that presented the best foam stability was HMW. When HMW is combined with MeLMW fraction, the foam stability largely increased. This increase was even larger, approaching the foam stability of the sparkling wine, when HMW was combined with the less hydrophobic subfraction of MeLMW (fraction 3). Electrospray tandem mass spectrometry (ESI-MS/MS) of fraction 3 allowed the assignment of polyethylene glycol oligomers (n = 5-11) and diethylene glycol 8-hydroxytridecanoate glyceryl acetate. To observe if these molecules occur in sparkling wine foam, the MeLMW was recovered directly from the sparkling wine foam and was also analyzed by ESI-MS/MS. The presence of monoacylglycerols of palmitic and stearic acids, as well as four glycerylethylene glycol fatty acid derivatives, was observed. These surface active compounds are preferentially partitioned by the sparkling wine foam rather than the liquid phase, allowing the inference of their role as key components in the promotion and stabilization of sparkling wine foam.     

Terpene compounds as possible precursors of 1,8-cineole in red grapes and wines

While the contribution of 1,8-cineole to the aroma of wine has been reported, it is a matter of controversy that the vineyards producing such wines are surrounded by Eucalyptus trees, which may contribute their essence to the grapes. However, experimental information presented in this paper suggests that 1,8-cineole can be produced by chemical transformation of limonene and alpha-terpineol, and this process may be responsible for the occurrence of Eucalyptus-like aroma in Tannat wines from vines not grown in the vicinity of Eucalyptus trees. A mechanism for the chemical transformation of these aroma compounds is proposed.     

Investigation of potent odorants and afterodor development in two Chardonnay wines using the buccal odor screening system (BOSS)

Potent odorants of two Chardonnay wines were characterized according to their specific overall aroma profiles and their intraoral release patterns after wine consumption. Therefore, aroma compounds were isolated and analyzed by means of high resolution gas chromatography-olfactometry (HRGC/O), leading to the detection of 36 odor-active compounds in both wines. All compounds were identified. Of the most potent odorants, 25 were quantified in both wines by means of stable isotope dilution assays. For the intraoral investigation of odor compounds at defined times after Chardonnay wine consumption, the recently developed buccal odor screening system was used. Significant differences in the oral persistence of characteristic odor notes were observed for both wines with mainly the characteristic barrique-notes being highly persistent, while fruity notes quickly disappeared from the oral cavity. The obtained analytical data were related to time-resolved retronasal aroma evaluation.     

Influence of yeast strain and aging time on free amino acid changes in sparkling ciders

An analytical method for the determination of free amino acids in ciders is reported. It is based on high-performance liquid chromatography with an automatic precolumn derivatization with o-phthaldehyde and 3-mercaptopropionic acid and diode array detection. The method was applied to monitor the amino acids during second fermentation of sparkling ciders. This paper reports the influence of yeast strains and aging time on the amino acid composition of sparkling ciders. The application of principal component analysis enables the ciders to be differentiated on the basis of the two factors considered (yeast strain and aging time). The first principal component, which accounts for 58% of the total variance, achieved the separation according to aging time with serine, glycine, alanine, valine, ornithine, leucine, and lysine as the most important variables. The second principal component, accounting for 28% of the explained variance, is closely related to aspartic acid and asparagine and separates the samples according to the yeast strain.     

Extraction of phenolics and changes in antioxidant activity of red wines during vinification.

The moderate consumption of alcoholic beverages has been associated with protection against the development of coronary heart disease. Although alcohol itself can help prevent coronary heart disease through a number of mechanisms, red wine appears to offer protection above and beyond that attributable to alcohol alone. Red wine is a complex fluid containing grape, yeast, and wood-derived phenolic compounds, the majority of which have been recognized as potent antioxidants. The aim of this study was to investigate the major phenolic contributors to the antioxidant activity of wine. To this end, four wines were followed during the first 7-9 days of vinification. Individual phenolic compounds were quantified by HPLC, and antioxidant activity was determined by electron spin resonance spectroscopy. The extraction of the phenolics was found to be influenced by vinification procedure, grape quality, and grape variety. Although fermenting wines reached a total phenolic content comparable to that of a bottled wine after 9 days of vinification, the antioxidant activity was significantly lower than that of a finished wine. This suggests that the larger polyphenolic complexes and condensation products that appear during aging make a sizable contribution to the overall antioxidant activity of red wines.     

Earthworm activity and soil structure changes due to organic enrichments in vineyard systems

 The effect of organic enrichment on earthworm activity and soil structure was studied in two French vineyards, by comparing control and test plots. In each vineyard the organic matter quantitatively increased the abundance and biomass of the earthworm community. These increases were associated with a higher level of species diversity and a higher evenness corresponding to the development of endogeic community. These earthworm community changes were associated with an increase in granular bioturbated areas and in macroporosity in the top soil layer. The micromorphological approach incorporated an original process of image analysis which appeared to be an appropriate method for characterizing pore morphology in this study. The pores when characterized by their size and shape could be related to ecological groups and growth stages of earthworms. Received: 4 August 1997     

Comparative changes in color features and pigment composition of red wines aged in oak and cherry wood casks

The color features and the evolution of both the monomeric and the derived pigments of red wines aged in oak and cherry 225 L barriques have been investigated during a four months period. For cherry wood, the utilization of 1000 L casks was tested as well. The use of cherry casks resulted in a faster evolution of pigments with a rapid decline of monomeric anthocyanins and a quick augmentation formation of derived and polymeric compounds. At the end of the aging, wines stored in oak and cherry barriques lost, respectively, about 20% and 80% of the initial pigment amount, while in the 1000 L cherry casks, the same compounds diminished by about 60%. Ethyl-bridged adducts and vitisins were the main class of derivatives formed, representing up to 25% of the total pigment amount in the cherry aged samples. Color density augmented in both the oak and cherry wood aged samples, but the latter had the highest values of this parameter. Because of the highly oxidative behavior of the cherry barriques, the use of larger casks (e.g., 1000 L) is proposed in the case of prolonged aging times.     

Early changes due to sorghum biofuel cropping systems in soil microbial communities and metabolic functioning

Evaluation of biofuel production cropping systems should address not only energy yields but also the impacts on soil attributes. In this study, forage sorghum (Sorghum bicolor L. Moench) cropping systems were initiated on a low organic matter soil (<0.9 %) with a history of intensively tilled low-input cotton production in the semiarid Southern High Plains of the U.S. Sorghum cropping systems were evaluated in a split-plot design with sorghum cultivar as the main plot and the combination of irrigation level (non-irrigated and deficit irrigated) and aboveground biomass removal rate (50 % and 100 %) as the split plot. The sorghum cultivars used varied in yield potential and lignin content, which are important features for feedstock-producing crops. Within 1 year, the transition from long-term cotton cropping systems to sorghum biofuel cropping systems resulted in increased soil microbial biomass C (16 %) and N (17 %) and shifts in the microbial community composition as indicated by differences in fatty acid methyl ester (FAME) profiles. Additionally, enzyme activities targeting C, N, P and S cycles increased 15–75 % (depending on the enzyme) after two growing seasons. Increased enzyme activities (16–19 %) and differences in FAME profiles were seen due to irrigation regardless of aboveground biomass removal rate. Biomass removal rate and the cultivar type had little effect on the soil microbial properties during the time frame of this study. Early results from this study suggest improvements in soil quality and the sustainability of sorghum biofuel cropping for low organic matter agricultural soils.     

Productivity increase in Northern Austria Norway spruce forests due to changes in nitrogen cycling and climate

We investigated the long‐term temporal trend in growth rate, soil chemical status, and nutrient content of needles of two Norway spruce (Picea abies) stands in the Bohemian Massif, Austria. The aim was to quantify changes in the site productivity over the last four decades as a consequence of the enriching effect of N deposition, rising CO₂ levels in the atmosphere, and changes in forest‐management practices. We used the data records of control plots from forest‐amelioration experiments that have been monitored for more than four decades. Both stands showed increased growth rates and a large deviation from the growth pattern of earlier applicable yield tables. The nutrient levels in the foliage remained unchanged and neither suggested luxury consumption nor nutrient imbalances. Results from soil chemistry analysis were inconclusive in respect of changes in soil conditions: an enrichment of the mineral soil with N and a decrease in the C : N ratio. Changes were confined to the uppermost part of the soil profile. Our data support the hypothesis that the sites are in a steady process of aggradation and that site productivity is rising.     

生态文明视角下四川省资源环境压力的时空变化特征

基于足迹家族原理,构建了由生态压力、温室气体(GHGs)排放、水资源压力构成的资源环境压力评价指标体系,并应用于四川省的资源环境压力评价。结果表明,1990—2013年四川省人均生态足迹增加109.57%,生物承载力变化不大,生态压力由中下(Ⅱ_a)升至很高(Ⅲ_b)等级;林业碳汇提高32.01%,GHGs排放虽保持较低(Ⅰ_b)等级,但其排放指数增高了234.97%;水足迹增速很小,水资源压力很低(Ⅰ_a);全省资源环境压力由很低(Ⅰ_a)升为中下(Ⅱ_a)。空间上,生态压力很低(Ⅰ_a)的是甘孜和阿坝,广元为中上(Ⅱ_b),成都、自贡和攀枝花等其余19市(州)很高(Ⅲ_b);GHGs排放状况,攀枝花很高(Ⅲ_b),内江较高(Ⅲ_a),乐山中上(Ⅱ_b),眉山中下(Ⅱ_a),甘孜、雅安和阿坝为碳汇(Ⅰ_a),成都、自贡和泸州等其余14市(州)均属较低(Ⅰ_b)等级;水资源压力方面,自贡、遂宁、眉山、内江和资阳很高(Ⅲ_b),成都较高(Ⅲ_a),泸州和达州为中上(Ⅱ_b),德阳为中下(Ⅱ_a),宜宾和攀枝花较低(Ⅰ_b),甘孜、阿坝和广安等其余10州(市)很低(Ⅰ_a);资源环境压力状况,阿坝、甘孜、雅安和广元很低(Ⅰ_a),凉山和绵阳较低(Ⅰ_b),广安、巴中和南充为中下(Ⅱ_a),宜宾、德阳、乐山和达州为中上(Ⅱ_b),泸州、资阳和成都较高(Ⅲ_a),遂宁、攀枝花、眉山、自贡和内江很高(Ⅲ_b)。研究表明,四川省的资源环境压力主要归因于较高的生态压力。今后的生态文明建设中,除了严守耕地生态红线以确保耕地生产力外,还要通过大力发展水电以优化能源消费结构,以及加强森林保育以提高碳汇潜力。     

Using segmented regression models to fit soil nutrient and soybean grain yield changes due to liming

Frequently soil-plant relationships and responses are complex combinations of increases-level-decreases consisting of linear segments of differing slope. Segmented regression is very useful to express and quantify such relationships and responses. Fitting segmented regression models to such data, however, remains a challenge. The problem is in estimating the join points and coefficients. We use median functions to express segmented regression models, and estimate the join points by standard estimation routines such as Marquardt, Newton, and doesn’t use derivatives (DUD) methods that are available in statistical software such as SAS. Segmented straight-line models are fit to data reflecting soil Manganese (Mn), Calcium (Ca), Phosphorus (P), and soybean yield changes under different soil pH conditions due to liming. A systematic comparison of the slopes and join points suggests that different mechanisms are limiting soybean yield at different intervals as soil pH increased.     

Soil physical and chemical changes due to tillage and their implications for erosion and productivity

A seven-year tillage trial was conducted in central New South Wales, Australia to measure the effect and extent of conservation tillage practices on soil physical and chemical properties. Three tillage treatments, traditional tillage (TT), reduced tillage (RT) and direct drilling (DD) were imposed on hardsetting red-brown earths at Cowra and Grenfell. A fourth treatment, direct drilling without grazing (NT) was imposed at Cowra only.

At Cowra there was a significant trend of reduced total runoff in the DD and NT treatments but not in the RT treatment. Runoff significantly increased in the TT treatment.

At Grenfell, runoff decreased in all treatments but only significantly in the DD and RT treatments. Similar trends in total sediment loss were measured at both sites.

Associated physical measurements of saturated hydraulic conductivity, sorptivity and bulk density confirmed that the changes in runoff were due to the creation of macroporosity greater than 0.75 mm diameter. The relationship between macroporosity, organic carbon and aggregate stability is discussed. Conclusions were that in these soil types runoff and sediment loss were affected more by destruction of macroporosity due to cultivation than changes in organic carbon from residue retention. To achieve these soil improvements using conservation tillage a continuous cropping period of four years was necessary to obtain significant and consistent trends.

Soil chemical data showed that total nitrogen increased with conservation tillage practices. Available phosphorus changes due to tillage were not observed because of more than adequate fertiliser applied. Soil pH decreased significantly in the DD and NT treatments at Cowra only. The implications of these chemical changes are discussed.     

Phenolic compounds and browning in sherry wines subjected to oxidative and biological aging

The composition in hydroxybenzoic and hydroxycinnamic acids, hydroxycinnamic esters, tyrosol, syringaldehyde, and flavan-3-ol derivatives of three different types of sherry wine obtained by aging of the same starting wine under different conditions was studied. So-called "fino" wine was obtained by biological aging under flor yeasts, "oloroso" wine by oxidative aging, and "amontillado" wine by a first stage of biological aging followed by a second oxidative step. On the basis of the results, the wines subjected to oxidative aging exhibited higher phenol contents, in addition to scarcely polar compounds absorbing at 420 nm that were absent in the wines obtained by biological aging. Taking into account that flavan-3-ol derivatives play an important role in wine browning, a model catechin solution was inoculated with flor yeast which, contrary to the findings of other authors in the absence of yeasts, formed no colored compounds. This different behavior may account for the resistance to browning of pale sherry wines in the presence of flor yeasts.