Colour and phenolic compounds in sweet red wines from Merlot and Tempranillo grapes chamber-dried under controlled conditions

Chamber drying under controlled temperature and humidity conditions of the red grape varieties Merlot and Tempranillo grown in Andalusia (Spain), and the fortification and maceration of the musts in the presence of skin from both types of grapes, to obtain sweet red wines, has been studied. Changes in colour and in monomeric and polymeric phenols during the vinification process were examined. Chamber drying increased the sugar content to about 31.4 °Brix within 48 h in Merlot grapes and 72 h in Tempranillo grapes. This drying process also causes skin rupture, facilitating the access of phenolic compounds to the pulp. The resulting musts exhibited slight browning and increased red hues, due to a high concentration of anthocyanins; maceration in the presence of grape skins for 24 h provided the best results. The end-product contained highly acceptable tannin, colour and phenolic compounds for marketing as a high quality sweet red wine, in comparison with other commercial sweet red wines.     

Influence of training system on chromatic characteristics and phenolic composition in red wines

Chromatic characteristics and phenolic composition of red wines elaborated from Sousón and Brancellao grapes (Vitis vinifera L.), whose vines were trained in cordon and Guyot systems, were determined. This comparison was possible because there were no significant differences between yields for each one. Hue was the only significantly different chromatic parameter for both training systems and cultivars. In Sousón cultivar, saturation, colour intensity and red percentage were greater for Guyot system. Sousón cultivar trained in Guyot system and Brancellao cultivar trained in cordon system were characterized by higher total anthocyanin concentration. However, greater ionization index and flavanols reagent with dimethyl aminocinemaldehyde were associated with Guyot and cordon systems, respectively, independently on cultivar. Furthermore, gentisic acid, as well as malvidin-3-glucoside, petunidin-3-acetylglucoside and malvidin-3-caffeoylglucoside in less extension, permitted to differentiate training systems in both Sousón and Brancellao cultivars. Principal component analysis was also performed for a better understanding of the differences found.     

Polyphenols and colour variability of red wines made from grapes harvested at different ripeness grade

Several red wines were elaborated in order to study the influence of the grape harvesting date (degree of maturity of the grape) on their chromatic characteristics and polyphenolic contents. Wines made from two grape varieties, at three different harvesting dates and from two consecutive vintages, were selected for this study. The results showed that the harvesting date of grapes (directly correlated with the degree of maturity of the grapes), influenced the chromatic characteristics of the wines, although their polyphenolic compositions were clearly different, especially in Cabernet Sauvignon wines. In general, higher intensities of blue or violet tones were detected in wines made from the grapes collected on the second harvesting date, in which the ratios anthocyanins/proanthocyanidins and anthocyanins/(proanthocyanidins + catechins) were the lowest. These ratios are proposed as probable indicators of the aptitude for wine ageing.     

Determination of phenolic compounds in wines: Influence of bottle storage of young red wines on their evolution

Various analytical methods based on the HPLC-DAD technique were used to determine 38 phenolic compounds in red wines. While anthocyanins and hydroxycinnamic acids were determined by direct injection of wine samples, hydroxybenzoic acids, catechins, procyanidins and flavonols required an analytical pretreatment involving liquid–liquid partitioning with ethyl ether followed by solid-phase extraction on C₁₈ mini-columns. The proposed analytical methods were used to establish the phenol composition of Mencía and Brancellao, two varietal young red wines, and its influence on colour stability during storage in bottles for one year. At the end of malolactic fermentation, Mencía wine was found to contain much greater amounts of anthocyan pigments than was Brancellao wine. This resulted in a higher colour density but a weaker hue in Mencía wine than in Brancellao wine. Phenolic compounds evolved similarly in both wines during storage; changes in such compounds involved a decrease in the levels of monomeric anthocyanins, phenolic acids, epicatechin and flavonols, and an increase in those of procyanidins. The absence of a relationship between the changes in colour density and monomeric anthocyanins in both wines suggests that copigmentation and polymerization with other phenolic compounds (viz. phenolic acids, catechins and/or flavonols) prevail over degradation of the pigments.     

Determination of phenolic compounds of grape skins during ripening by NIR spectroscopy

The potential of near infrared spectroscopy (NIRS) to determine the content of phenolic compounds in red grapes has been evaluated. The near infrared spectra of intact grapes and grape skins throughout maturity were recorded using a fibre-optic probe and a transport quartz cup, respectively. Reference values of phenolic compounds were obtained by HPLC-DAD-MS. Modified Partial Least Squares (MPLS) regression was used to develop the quantitative models for flavanols, flavonols, phenolic acids, anthocyanins and total phenolic compounds. The procedure reported here seems to have an excellent potential for fast and reasonable cost analysis. The results of this work show that the models developed using NIRS technology together with chemometric tools allow the quantification of total phenolic compounds and the families of main phenolic compounds in grape skins throughout maturation. The validation of these models showed the best results for the determination of flavonols (differences between HPLC and NIRS of 7.8% using grapes and 10.7% using grape skins) in the external validation procedure. Good results in the external validation were also obtained for the determination of total phenolic compounds (differences of 11.7% using grapes and 14.7% using grape skins). The best results were generally obtained recording the spectra directly in intact grapes.     

Changes in contents of phenolic compounds during maturing of barrique red wines

Concentrations of derivatives of benzoic and cinnamic acids and furaldehyde were studied during maturing of a red wine (a mixture of Cabernet Sauvignon and Merlot) in barrique barrels (Quercus robur). Samples were taken at three-week intervals over 6 months. The influence of degree of toasting of the wood on the amount of phenolic compounds in barrique wine was also investigated. The samples were pre-separated using a solid-phase extraction on an RP 105 polymeric sorbent and analysed by high-performance liquid chromatography with UV-DAD detection. Gallic, protocatechuic, p-hydroxybenzoic, vanillic, caffeic, syringic, p-coumaric, ferulic, benzoic and ellagic acids and p-hydroxybenzaldehyde, vanillin, 2-furaldehyde, 5-methoxy-2-furaldehyde and 5-methyl-2-furaldehyde were identified in the extracts of natural and toasted wood chips and in the extracts of the wine. Syringaldehyde was identified only in the extracts of the toasted wood chips. Ellagic acid can be regarded as a characteristic compound of barrique wine ageing and its constant level during some periods could become a marker of maturity of barrique wines. Due to the absence of furaldehydes in natural wines, these compounds can be considered as typical components of barrique wines and so they can serve as a marker of authenticity of barrique wines.     

低分子量岩藻多糖的生产途径及药理作用

介绍了近年来一些产岩藻多糖酶的微生物菌株及酶的固态发酵条件，经过酶解得到低分子量的岩藻多糖，有着诸多药理作用。     

Original article: Prediction of the colour and polyphenolic composition of the young red wines from the phenolic potential of the grapes

The phenolic potential of the grapes of Tannat, Cabernet Sauvignon and Merlot produced in the south region of Uruguay was analysed in four years. The grapes of Tannat had the highest total phenolic richness (A280 = 80.0), total anthocyanin potential (ApH1 = 2540 mg L^?1) and extractable anthocyanin potential (ApH3.2 = 1269 mg L^?1), although there were important differences between the years. Representative winemaking of each vineyard was carried out. The differences verified in the grapes phenolic indexes were related to the colour and polyphenolic composition of the wines. The correlations between the phenolic indexes of the grapes and the colour and polyphenolic composition of the wines were very high. The estimation of the polyphenolic richness and the extractability of the anthocyanins of the grapes allow to improve the management of the winemaking and the prediction of the chromatic characteristics and the global polyphenolic composition of the wines.     

Determination of fermentative volatile compounds in aged red wines by near infrared spectroscopy

The purpose of this work was to study the possibility of determination of fermentative volatile compounds in aged red wines using NIR spectroscopy. To achieve this, 240 wines belonging to different geographic zones and elaborated with one or two varieties were analyzed. The volatile compounds were quantified by SBSE-GC–MS. Spectra obtained by NIR were co-related with these values using partial least square (PLS) regression. Calibration and validation statistics showed the quality of the model, after all when is done separately for each of the four geographic zones, and in the case of wines elaborated with two varieties. Consequently, near infrared spectroscopy can be used as an easy and rapid tool to determine fermentative volatile compounds in aged red wines.     

Influence of major polyphenols on antioxidant activity in Mencía and Brancellao red wines

The purpose of this work was to examine the relationship of the total polyphenol index (TPI) as measured spectrophotometrically and individual phenols as determined by HPLC to antioxidant activity in red wines made from two Vitis vinifera grape varieties grown in NW Spain (viz. Mencía and Brancellao) during bottled storage in the dark for 12 months. Antioxidant activity was determined by using various methods based on inhibition of the coupled oxidation of the β-carotene/linoleic acid mixture. Also, free radical scavenging activity was determined with 2,2-diphenyl-1-picrylhydrazyl (DPPH). Antioxidant activity as measured by DPPH after storage for 3 months was higher in Mencía wines than in Brancellao wines (4.5 ± 0.60 vs. 3.7 ± 0.30 mmol/L trolox equivalents). Beyond 3 months of storage, radical scavenging activity increased in both types of wine (from 4.5 ± 0.60 to 6.0 ± 0.80 mmol/L in Mencía wines and from 3.7 ± 0.30 to 4.7 ± 0.71 mmol/L trolox equivalents in Brancellao wines). The significant correlation found between antioxidant activity and TPI in all wines (r > 0.88) is indicative of the significance of condensation and polymerisation products to the total antioxidant activity of the wines. The relatively high correlation of total flavonols (r = 0.89) and acylated anthocyanins (r = 0.70) as measured by HPLC with to the overall antioxidant capacity suggests that these two polyphenol classes can substantially influence the antioxidant properties of these wines. The linoleic acid/β-carotene assay exposed a higher antioxidant capacity in Brancellao wines than in Mencía wines after 3 months of storage (6.0 ± 0.80 vs. 4.7 ± 0.70). Most of the studied wines lost an average 45% antioxidant activity during bottled storage. Antioxidant activity as measured with the linoleic acid/β-carotene assay was closely correlated with both hydroxycinnamic acids (r = 0.90) and flavanols (r = 0.71 and 0.61 for monomeric and polymeric forms, respectively).     

小分子(M≤8000)肝素制备工艺的研究

试验以牛肺为原料提取肝素粗品,采用酶解结合氧化法精制肝素,提高肝素的效价,通过亚硝酸钠控制解聚法制备分子量在4000～7000D的低分子量肝素。通过正交试验考察了反应时间、亚硝酸钠浓度、溶液pH值等条件对解聚反应的影响。用红外图谱对其结构进行了鉴定,测定了产物的分子量,经Sephadex G-75凝胶色谱柱对解聚的低分子量肝素进行分离纯化。     

Consideration of the influence of aging process,type of wine and oenological classic parameters on the levels of wood volatile compounds present in red wines

The contents of the volatile compounds extracted from wood: cis- and trans-whiskylactones, vanillin, syringaldehyde, furfural, 5-methylfurfural, eugenol, guaiacol, p-ethyl-phenol and p-ethylguaicol have been studied in 12 single-variety wines aged in new American oak barrels. The concentration of these compounds were determined after the following combinations of time in wood and time in bottle: 0 months in wood plus 18 months in bottle, 4 months in wood  + 14 months in bottle, 9 months in wood + 9 moths in bottle and 12 months in wood + 6 months in bottle. According to the composition of the wines, it is possible to conclude in general, that, the extraction of these compounds was faster during the first four or 9 months of aging in wood, depending on the wines. After 12 months of oak maturation, the extraction of these compounds slowed down. Furthermore, the final concentrations of these volatile compounds were different among studied wines. These differences could be related to some of the values of some of their oenological parameters, such as the contents of tartaric acid and sulphur dioxide of each wine.     

磁场对新鲜干红葡萄酒酚类物质影响的研究

为了缩短葡萄酒陈酿时间,使其品质在较短时间内得到改善,本文将磁场处理后的新鲜干红葡萄酒采用反相高效液相色谱法测定其黄烷-3-醇和酚酸两种酚类物质的含量,然后将这两种酚类物质含量的变化与其经自然陈酿后的变化相比较.研究结果表明,随着磁场处理时间的延长,5种黄烷-3-醇和11种酚酸的含量都发生了复杂的变化,且变化趋势基本符合自然陈酿效果.因此,磁场处理对于加速葡萄酒陈酿、提高葡萄酒品质是具有一定效果的.     

Extraction/oxidation kinetics of low molecular weight compounds in wine brandy resulting from different ageing technologies

This study provides innovative information on the influence of new technologies of ageing (stainless steel tanks with wood staves or wood tablets of chestnut or Limousin oak), in comparison with traditional technology (oak wooden barrels), on the extraction/oxidation kinetics of low molecular weight compounds of wine brandy. The brandy was sampled and analysed by HPLC during the first year of ageing. The results show that most of the compounds tend to increase over the time, but their extraction/oxidation kinetics depend on the ageing technology. The wooden barrels promote greater enrichment in the majority of the compounds. However, gallic acid, ellagic acid and syringaldehyde, and vanillin and 5-methylfurfural, which are strong antioxidants and key-odourant compounds, respectively, present higher contents in the brandy aged with the alternative technologies. Chestnut proves to be a suitable alternative to Limousin oak for the ageing of brandy in all the studied technologies, inducing faster evolution and high quality.     

Influence of the elaboration process on the peptide fraction with angiotensin I-converting enzyme inhibitor activity in sparkling wines and red wines aged on lees

The influence of some variables on the manufacturing process for sparkling and red wines on the angiotensin I-converting enzyme inhibitory (ACEI) activity has been studied. Ageing on lees significantly influenced the angiotensin I-converting enzyme inhibitor activity in sparkling wines. It reached maximum values at 9 months, decreasing afterwards. In red wines, the ACEI activity also increased in the wines aged on lees. In both wines, hydrophobic peptides were responsible for the ACEI activity. These peptides would make a much greater contribution to the total activity if present in higher proportions. It would therefore be advantageous to increase their concentrations in wines, either by using starting materials with high initial peptide contents or by using a highly autolytic yeast, giving a greater degree of hydrolysis of wine proteins, and higher concentrations of peptides with ACEI activity.     

Effect of molecular weight of chitosans on their antioxidative activities in apple juice

This work studies how chitosans with low molecular weight (LMWC, M_W = 12 kDa), medium molecular weight (MMWC, M_W = 95 kDa) and high molecular weight (HMWC, M_W = 318 kDa) affect antioxidant activity in an aqueous system and in apple juice. Antioxidant activity was determined, including that of DPPH radicals, hydrogen peroxide and superoxide anion radicals, as well as metal ion chelating capacity, ABTS radicals of chitosans with different molecular weights (DMWCs) in apple juice.     

Varietal and geographic classification of French red wines in terms of pigments and flavonoid compounds

Thirty-four French red wines originating from six different grape varieties and three different production areas were analysed in duplicate for 15 anthocyanins, ten flavonoids and three colour parameters, F-statistics, principal component analysis and stepwise discriminant analysis were used to identify and to explain differences among samples. Clear difference between wines made from different varieties were mainly related to anthocyanin 3-acylglucosides. Malvidin and peonidin 3-acetylglucosides were found in increasing concentrations in wines made respectively from Grenache, Carignan, Cinsault, Merlot, Carbernet Sauvignon and Cabernet Franc grapes; the concentrations of peonidin and malvidin 3-p-coumarylglucosides were higher in the Cinsault wines studied. Cabernet Sauvignon and Merlot wines made near Bordeaux had a less intense colour and a higher malvidin 3-glucoside content than wines from the same varieties produced near Narbonne. Wines made from Merlot, Cabernet Sauvignon and Cabernet Franc grapes contained more catechin, epicatechin and myricetin when produced in the south than in the north (Narbonne, Bordeaux, Angers). Of the samples analysed, 96%, and all of the nine extra wines, were correctly classified according to the variety of the grapes using four anthocyanins and catechin selected by step wise discriminant analyses.     

Employment of near infrared spectroscopy to determine oak volatile compounds and ethylphenols in aged red wines

The aim of this work was to study the ability of NIR spectroscopy to determine oak volatile compounds and ethylphenols levels in aged red wines. For this purpose 510 wines aged with different storage time and in different oak barrel types were analyzed. Calibration models were developed from SBSE-GC–MS and NIR data using partial least squares (PLS) regression. In order to validate the calibration, full cross validation was employed. Results showed that the calibration statistics were very good (R² > 0.86) for all the compounds studied. In wines aged in French and in American and French oak barrels, and in “reserva” and “gran reserva” wines, the residual predictive deviation (RPD) obtained was higher than 1.5 in all the compounds and it was higher than 2 in some of the cases. In conclusion, near infrared spectroscopy can be used as a rapid tool to determine oak volatile compounds and ethylphenols in aged red wines.     

Statistical interpretation of the color parameters of red wines in function of their phenolic composition during aging in bottle

The relationships between the color parameters (colorimetric indexes and CIELAB variables) and the phenolic components (anthocyanins, pyranoanthocyanins, hydroxybenzoic and hydroxycinnamic acids, flavanols and flavonols) of young red wines from Vitis vinifera L. cv. Tempranillo, Graciano and Cabernet Sauvignon (vintage 2000, Navarra, Spain), have been investigated during 26 months of wine aging in bottle (a period embracing their commercial life), through the application of different statistical analysis (principal component, correlation and polynomial regression). The results of the principal component analysis first indicated that for each variety a high degree of interrelation existed between the color parameters and the anthocyanin pigments. Moreover, it was found that for each variety the color parameters were correlated with the anthocyanins during aging in bottle. Finally, by the application of polynomial regression analysis, both anthocyanins (simple glucosides and acetyl-glucosides) and pyranoanthocyanins (anthocyanin-pyruvic acid adducts) were selected as the variables that best described the different color parameters during aging in bottle. However, differences were found between varieties in relation to the type of anthocyanin pigment selected for describing each color parameter, finally indicating the importance of the grape variety factor in the definition of the wine chromatic characteristics.     

Changes in chromatic characteristics and phenolic composition during winemaking and shelf-life of two types of red sweet sparkling wines

The Brachetto variety is the most important aromatic red grape used for the production of sweet sparkling wines in Italy. The phenolic composition and chromatic characteristics were studied in base and red sweet sparkling wines made from this variety. The present work represents the first study on sparkling wines manufactured with Brachetto grapes. The amount of pigments extracted in the base wine was low as a consequence of the necessity for short maceration time (48 h) and low alcohol content (< 3.5% v/v). The second fermentation (prise de mousse) caused a pigment content decrease, accompanied by both a color intensity decrease and a tonality increase. In terms of phenolic compounds and chromatic characteristics, lightly sparkling wines (final bottle pressure < 1.7 bar) agreed with fully sparkling wines (final bottle pressure > 3.0 bar) at the end of the second fermentation and, therefore, the chromatic quality was independent on the winemaking methodology used, excepting for lightness and color intensity.Response surface methodology was applied to predict the effect of two independent variables, namely time and temperature of storing, on the phenolic composition and chromatic properties in both lightly and fully sparkling wines. So, it is possible to evaluate the development of two types of sweet sparkling wines during their ageing in bottle and their commercial shelf-life. A central composite design (CCD) and response surface methodology (RSM) were used for this purpose. Quantitative changes were observed in the color parameters. Although the time variable strongly influenced them, the two sparkling wines were stable enough only at low temperatures after 12 months of ageing. During the wine ageing in bottle, an increase in the formation of polymeric red pigments can be suggested taking into account the losses observed in monomeric anthocyanins. The results obtained showed that the color of fully sparkling wines was more stable than that of lightly ones and, therefore, the shelf-life of the former ones could be longer.