Antioxidant and antimicrobial properties of polyphenolic fractions from selected Moroccan red wines

The present study is the first effort to a comprehensive evaluation of the antioxidant and antimicrobial activities of fractionated red wines from Morocco. The results obtained revealed that the wine samples were characterized by a higher phytochemical concentration than the same variety of wines with a different geographical origin and other more consumed red wines, confirming what was reported in a previous authors' work. The most phenolic-rich fractions were the ones containing phenolic acids and quercetin glucoronides from Syrah and Merlot wine samples while Cabernet Sauvignon exhibited the highest monomeric anthocyanin content. The antioxidant activity of wine extracts was tested by ferric reducing antioxidant power and 1,1-diphenyl-2-picrilhydrazyl assays. Samples revealed a higher reducing capacity than radical scavenging property and a good correlation between antioxidant activity and polyphenolic content values. As regards the antimicrobial properties, each fraction exhibited activity against a broad spectrum of food-borne microorganisms, revealing not only a moderate to high natural preserving capacity, but also potentially beneficial influence on human health. PRACTICAL APPLICATION: In consideration of the scarcity of data regarding composition and biological properties of Moroccan red wines, the present study may represent a valuable reference for wine consumers and producers.     

Presence of cork-taint responsible compounds in wines and their cork stoppers

 Chloroanisoles [2,4-dichloroanisole, 2,4,6-trichloroanisole (TCA), 2,3,4,6-tetrachloroanisole and pentachloroanisole], chlorophenols [2,4,6-trichlorophenol, 2,3,4,6-tetrachlorophenol and pentachlorophenol (PCP)] and guaiacol were detected in red and white cork-tainted bottled wines. These compounds were also found in the cork stoppers from those bottles. A significant correlation was found between TCA in wines and TCA in cork stoppers, and between TCA in wine and intensity of cork taint. At low levels of TCA, the presence of guaiacol or PCP were also found to influence in cork taint. Received: 29 November 1999     

An invertase fragment responsible for improving the protein stability of dry white wines

The thermoprotective effect of yeast parietal mannoproteins improves the protein stability of white wines aged on their lees (sur lie). The substance responsible for this is an N‐glycosylated, 31.8 kDa mannoprotein that corresponds to a parietal invertase fragment of Saccharomyces cerevisiae. This mannoprotein is released into the wine during autolysis of the lees by the combined action of β‐glucanases from the cell wall and the yeast's vacuolar protease. This mannoprotein may be obtained industrially by extracting yeast mannoproteins using enzymatic digestion of the cell wall with commercially prepared β‐glucanases (Glucanex^TM ‐Novo‐Nordisk). A wine's susceptibility to protein breakdown may be considerably reduced by adding this mannoprotein extract. As a result, less bentonite is needed to stabilise the wine. © 1999 Society of Chemical Industry     

Protein A-tagging for purification of native macromolecular complexes from Candida albicans

Protein A-tagging has become an important tool in characterization of protein-protein interactions in many systems, allowing purification of multicomponent complexes under native conditions. Here we provide a set of vectors that allow protein A-tagging in Candida albicans, through addition of the tag to open reading frames. These vectors were successfully used to generate stably tagged proteins that were functional, shown to be localized appropriately or assembled into complexes. These new vectors comprise a useful addition to the C. albicans molecular toolbox.     

天然大豆球蛋白亚基的分离纯化

利用变性剂脲和还原剂β-巯基乙醇解聚大豆球蛋白,在还原条件下通过DEAE琼脂糖凝胶F阴离子交换层析分离大豆球蛋白亚基,并对制备的亚基进行复性,从而建立了系统的分离纯化大豆球蛋白天然亚基的方法。对该方法分离亚基的产率和亚基的纯度进行评定,并利用大豆球蛋白免疫家兔制备的抗血清检测各种纯化亚基的免疫活性。结果表明：在还原条件下利用阴离子交换层析,可以有效地分离大豆球蛋白的碱性亚基和不同种类的酸性亚基。该方法的产率较高,以大豆球蛋白分离纯化碱性亚基及酸性亚基A1a,A2,A3,A4的产率分别为23．93％,14．95％,14．33％,12．06％,7．12％。制备的碱性亚基和酸性亚基A1a,A2,A3,A4的纯度分别为84．39％,90．48％,92．00％,65．91％,85．00％;纯化亚基能与抗大豆球蛋白血清特异性结合,具有免疫活性。     

The use of phenol compounds as parameters for distinguished red and rose wines from pale wines in multivariate analysis

The concentration of different types of phenol compounds and the ratio of such compounds to total phenols was established for red, rosé, and pale (claret) wines. Linear discriminant analysis was applied to these parameters to differentiate the red and rosé wines from the pale wines. Two discriminant functions correctly classified 100% of the red and rosé wines and 93.3% of the pale wines, with classification errors of 0.87% for the red wine-pale wine function and 1.7 × 10^–4% for the rose wine-pale wine function.

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Verwendung der Phenole bei der linearen Diskriminanzanalyse zur Trennung der Rot- und Roseweine yon Klaret-Wein

Zusammenfassung Man hat für Rot-, Rosé- und Klaret-Wein die Konzentration bestimmter Phenolanteile bestimmt und weiterhin ihr Verhältnis zu den gesamten Phenolen. Diese Parameter wurden mit der linearen Diskriminanzanalyse gemessen, mit dem Ziel, die Rot- und Roséweine von den KlaretWeinen zu unterscheiden. Zwei diskriminierende Funktionen reichen aus, um 100% der Rot- und Roséweine und 93,3% der Klaret-Weine zu klassifizieren, bei einer Fehlerquote yon 0,87% für Rot- zu Klaret-Wein und von 1,7 x 10^–4% für Rosé- zu Klaret-Wein.

     

Modification of the polyphenolic and aromatic fractions of red wines aged on lees assisted with ultrasound

The ageing on lees is a technique particularly interesting in the production of red wines due to the possibility of enhancing some of their sensory characteristics. Different authors have researched the ultrasound assistance to accelerate this ageing process in wines. The present work evaluated the modification that both fractions, polyphenolic and aromatic, of red wines suffer during the ageing on lees process assisted with ultrasounds and with the addition of oak chips. The results obtained during the experimental design indicate that the ultrasound treatment decreased the concentration of proanthocyanidins (between 20.3% and 32.8% with and without oak chips, respectively) and the total pigment content (with the highest reduction in the control sonicated wine 55.9% without chips and lees and from 47.8% to 48.9% when having oak chips/lees and lees, respectively). In addition, it has been observed that the ultrasound treatment did not affect the amount of fermentative volatile compounds present in the wine but, it increased the concentration of phenolic aldehydes coming from oak wood chips (10.8% in control wine and from 35.92% with oak chips/lees to 55.8% with lees).     

Ageing impact on the antioxidant and antiproliferative properties of Port wines

This study is focused on the impact of Port wine ageing on some antioxidant features and antiproliferative properties towards human cancer cells. For this, two types of Port wines with different ageing stages were used: a young Vintage and a 20-year-old Tawny. The wines were dealcoholized and two wine phenolic fractions were also characterized and tested. The radical scavenging capacity was similar amongst the wines tested but the reducing capacity was significantly reduced for both Port wine extracts. The results from the FRAP assay, but not DPPH, seem to be positively correlated with the amounts of phenolics with lower structural complexity.MKN-28 (stomach) was found to be the most susceptible cell line to the antiproliferative effect of the young Vintage Port. However, for all wines, Caco-2 (colon) was the cell line that showed the lowest IC₅₀. Interestingly, the old Tawny Port was found to maintain some antiproliferative activity.     

Fractionation and partial characterization of protein fractions present at different stages of the production of sparkling wines

Soluble proteins from sparkling wines (var. Chardonnay) manufactured industrially following the Champenoise method were analysed by analytical anion-exchange FPLC (fast protein liquid chromatography). Samples of the must, the unfined wine, the fined wine and the sparkling wines after 3, 6, 9, 12, 15 and 18 months of ageing with yeast lees were taken. Eight main must protein fractions were collected and characterized by isoelectric focusing and capillary electrophoresis. Six fractions consisted of proteins with isoelectric points (pIs) from 4.27 to 3.04. Two fractions, according to their UV spectra, seemed to contain phenolic compounds. A comparison of FPLC profiles of the must, the unfined wine and the fined wine indicated that both fermentation and stabilization processes decrease the concentration of those proteins with less affinity for the anion-exchange column and with a higher pI. No changes in the protein profiles of sparkling wines were observed during the first 18 months of ageing with yeast..     

酚类物质的结构与性质及其与葡萄及葡萄酒的关系

酚类物质是一类大而复杂的化合物。葡萄与葡萄酒中常见的酚类物质可分为类黄酮和非类黄酮两大类，它们是葡萄中重要的次生代谢产物，与葡萄的抗病性、采后生理、贮存、保鲜等密切相关。葡萄酒中的酚类物质来自于葡萄果实、果梗、酵母代谢以及橡木桶，参与形成葡萄酒的味道、骨架、结构和颜色等，对红葡萄酒的特征和质量尤其重要。     

Polyphenolic compounds and antioxidant properties of selected China wines

Thirty-seven China wines, produced from different geographical origins, were examined in this study. The antioxidant activity of wines was measured by different analytical methods: oxygen radical absorbance capacity (ORAC), reducing power, 2,2-azino-di-(3-ethylbenzothialozine-sulphonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH·), hydroxyl radical-scavenger activity, superoxide radical-scavenger activity, lipid peroxidation and chelating capacity. Furthermore,total phenols, total flavonoids, total flavanols and total anthocyanins of wines were determined. As expected, the red wines had much higher phenolic content and antioxidant capacity than rosé wines or white wines. Among the red wines, Cabernet Sauvignon and Muscat Hamburg, respectively, represented the wines with the highest and lowest phenolic contents and antioxidant capacity. Among the white wines, Italian Riesling had the lowest phenolic content and antioxidant capacity. Taken together, a close relationship between phenolic contents and antioxidant capacity, for all wines, was observed.     

A comparative study on the antioxidant properties of Slovakian and Austrian wines

The antioxidant properties of 86 wine samples (35 white and 17 red from the Slovak, and 12 white and 22 red from the Burgenland, regions) were investigated by Electron Paramagnetic Resonance (EPR) spectroscopy using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt cation radical (ABTS⁺) as oxidants. Generally, the red wines showed, on the average, more than 10 times higher antioxidant activity towards ABTS⁺ than the white wines. A similar ratio was found for the total phenolics content. A linear correlation was found between the antioxidant activities determined by DPPH and ABTS⁺ and the phenolics concentration. This trend is supported by the significant difference of the total integral value of the aromatic region in ¹H NMR (Nuclear Magnetic Resonance) spectra between the red and white wine samples. The content of the phenolic acid components of 16 selected wine samples determined by High Performance Liquid Chromatography (HPLC) correlates with the antioxidant activities. No significant differences were found between Slovakian and Austrian wines.     

Short communication: Identification of the aroma compounds responsible for the floral/rose flavor in water-soluble fractions of Manchego cheese

Water-soluble fractions from Protected Denomination of Origin Manchego cheese, with molecular weight <1,000 Da, were fractionated using gel permeation chromatography and studied using both instrumental and sensorial analysis. In 2 of the fractions, panelists detected a floral, rose-like flavor. Analysis of these fractions by gas chromatography-mass spectrometry after simultaneous distillation extraction with dichloromethane identified 2-phenylethanol and phenylacetaldehyde as the compounds responsible for this flavor.     

Antiglycative and antioxidative properties of coffee fractions

In this work the inhibitory activity of coffee low molecular weight compound (LMWC) and high molecular weight compound (HMWC) fractions against in vitro advanced glycation end-products (AGEs) formation was investigated. The HMWC fraction was characterised for its content in total phenolic groups, proteins and carbohydrates. The chlorogenic acids of LMWC fraction were identified by liquid chromatography coupled with tandem mass spectrometry. HMWC inhibited bovine serum albumin glycation by acting as radical scavenger and Fe-chelator in the post-Amadori phase of the reaction and by inhibiting dicarbonyl reactive compounds production during glucose autoxidation. LMWC fraction was able to inhibit protein glycation and dicarbonyl reactive compounds formation more than HMWC fraction. Chlorogenic acids are the main compounds responsible for the antiglycative activity of LMWC fraction.     

Principal component analysis of the polyphenol content in young red wines

In the present study the content of 15 polyphenols was determined in 55 samples of red wines from different denominations of origin in the Canary Islands (Spain) using high performance liquid chromatography (HPLC) with UV and fluorescence detection. The most important differences in content among wines according to different categories (island, zone and denomination of origin) were established. In general, red wines from the Canary Islands had a content in polyphenols in the lower part of the range considered normal. The exception was quercetin, with a mean content (17.5 mg/l) higher than in other wines, which may be a peculiarity of these particular wines. The principal component analysis (PCA) technique was used to study the latent structure. A good differentiation among wines according to their production area was obtained using linear discriminant analysis (LDA).     

Phenolic compounds and antioxidative properties of selected wines from the northeast of Thailand

The phenolic contents and antioxidative properties of selected wines, produced in the northeast of Thailand, were evaluated and compared, particularly those produced at Suranaree University of Technology (SUT) Farm as a case study. Nine wine varieties were used to evaluate their total phenolic content (TPC) by Folin–Ciocalteu method, free radical scavenging efficacy by DPPH method and reducing power by ferric reducing-antioxidant power (FRAP) method. The red wines had significantly higher (p < 0.05) amounts of total phenols, flavonoids and antioxidant activities (AA) compared to white wines. Capillary electrophoresis (CE) was used as a powerful and high performing tool for analysis of principal phenolic compounds in the wines. t-Resveratrol was found in Shiraz, Zinfandel and blended wine varieties. (+)-Catechin was found in all wine varieties, except in Chasselar Dore. (+)-Catechin was present in wines at a higher level than (−)-epicatechin. In red wine, gallic acid was the dominant phenolic acid found.