Antioxidant activity and phenolic content of wine vinegars produced by two different techniques

BACKGROUND: The presence of phenolics in fruit, red wine and vinegar has positive health effects due to their significant antioxidant activity. The aim of the study was to determine the effects of two different vinegar production methods on antioxidant activity and phenolic level of vinegars derived from Ulugbey Karasi grapes. Traditional surface and industrial submerge methods were used to make vinegar. Samples were taken from fresh red grape juice, maceration, wine, traditional vinegar and industrial vinegar. RESULTS: Total phenolic content of traditional and industrial vinegar samples were 2690 mg L^?1 and 2461 mg L^?1 GAE, respectively. ORAC values of traditional and industrial vinegar samples were 10.50 µmol mL^?1and 8.84 µmol mL^?1 TE, respectively. Antioxidant activity values of traditional and industrial vinegars were 13.50 mmol L^?1 and 10.37 mmol L^?1 TEAC, respectively. Gallic acid, catechin, epicatechin, chlorogenic acid, caffeic acid, syringic acid, p‐coumaric acid and ferulic acid were detected in grape juice, wine and vinegar samples. The content of catechin in industrial vinegar (27.50 mg L^?1) was significantly higher than that of in traditional vinegar (13.76 mg L^?1) (P < 0.05). Traditional vinegar had higher amounts of chlorogenic and syringic acids than the industrial vinegar (P > 0.05). CONCLUSION: Results of this study showed that different production methods affected the functional constituents of wine vinegars. Copyright © 2010 Society of Chemical Industry     

Phenolic composition and sensory characteristics of Cabernet Sauvignon wines: effect of water stress and harvest date

The effect of three water status level and two harvest date 55 and 64 days after veraison (DAV) on phenolic and sensory composition of Cabernet Sauvignon wines were investigated. The later harvest date led to wine with a higher alcohol content. Total phenols varied from 1439.66 to 1643.08 mg L^?1 with higher values at 64 DAV. No differences were observed between irrigation treatments. For total tannins and anthocyanins, no differences were found between harvest date. Separation of proanthocyanidins by Sep‐Pak Plus tC₁₈ cartridges showed only differences in concentration but not in the proportion of proanthocyanidin fractions. The wines from the most restricted treatment had a better colour and the same aroma of red fruits, persistence, astringency, fullness and bitterness, as the wine from the treatment with highest irrigation. Under the assay conditions, it was possible to obtain wines with a similar chemical and sensory composition earlier and using less irrigation water.     

Effect of Oak Chips on Evolution of Phenolic Compounds and Color Attributes of Bog Bilberry Syrup Wine During Bottle‐Aging

This study investigated the evolution of phenolic compounds of bog bilberry syrup wine during a bottle‐aging process, and further estimated the oak chip treatment on the wine color alteration. The wine was macerated with oak chips (2 or 5 g/L under light or medium toasting level) for 20 d and then bottle‐aged for 6 mo. Results showed that the oak chip treatment significantly increased the content of phenolic compounds and enhanced the copigmented anthocyanin level before aging. It also resulted in an increase on a^* and C^* but a decrease on L^*, b^*, and H^* of the wine. During aging process, a content decrease of total phenol and antioxidant capacity of the wine was observed. Phenolic acids, flavonol glycosides, and anthocyanins reduced the content, whereas flavonol increased the content. Free and copigmented anthocyanin levels decreased, whereas polymerized anthocyanins level increased. This process caused an increase on L^*, b^*, and H^*, but a decrease on a^* and C^*. The oak chip treatment delayed the wine color change and its effect was mainly depended on the addition amount. Partial least square regression revealed that flavonol glycosides, phenolic acids, and anthocyanins displayed a positive correlation with L^*, b^*, and H^*, but a negative correlation with a^* and C^*. Quercetin‐3‐O‐glucuronide, myricetin‐3‐O‐galactoside, chlorogenic acid, and quercetin exerted a more important effect on the color alteration in wine.     

Influence of sequential inoculum of Starmerella bacillaris and Saccharomyces cerevisiae on flavonoid composition of monovarietal Sangiovese wines

The selection of Starmerella bacillaris strains to be used with Saccharomyces cerevisiae as mixed cultures has been recently suggested in order to produce wines containing lower ethanol and higher glycerol concentrations and to promote fructose degradation due to their fructophilic character. However, studies about effects of such mixed starter cultures on phenolic compounds, which are responsible for the colour and health-enhancing properties in red wines, are currently lacking. Therefore, in this work, the influence of sequential inoculated fermentation (SIF) with Starm. bacillaris and S. cerevisiae on phenolic content of monovarietal Sangiovese wine was evaluated by fermentations at laboratory scale. Axenic fermentations (AXFs) with S. cerevisiae were performed as control. S. cerevisiae attained higher cell densities in AXF compared with SIF. The experimental wines obtained by SIF showed significant lower ethanol and higher glycerol concentrations, whereas no significant difference was detected in colour intensity. The total phenol index reached significantly lower values in SIF. Furthermore, the wines produced by SIF contained higher concentrations of vitisin A that has a greater colour stability than the anthocyanin monomer. Finally, a lower content of both free anthocyanins and flavan-3-ols, key compounds for wine quality possessing also health-enhancing properties, was found in wines obtained by SIF. On the contrary, no significant difference was detected on flavonol concentration between SIF and AXF. This study highlighted that the use of sequential inoculum of Starm. bacillaris and S. cerevisiae can contribute to increasing the colour stability of red wines, even if at the expense of compounds with health properties.     

Inhibition and inactivation evaluation of exogenous glycosidases in wines using p‐nitrophenylglycosides

BACKGROUND: Glycosidases are often used to improve the aroma of wines via hydrolysis of glycosidic precursors. The aim of this work was to develop a method to test activity and stability of these enzymes in wine environments using p‐nitrophenylglycosides, avoiding interference by colored substances. RESULTS: The proposed procedure for determination of glycosidase activity in wines involves quantification of the hydrolysis product p‐nitrophenol by HPLC. The method was applied to compare the inhibition of some commercial glycosidases by red and white wines. It was found that inhibition of a β‐D ‐glucosidase by ethanol, glucose and gluconolactone was smaller than that produced by wine. This enzyme was also inhibited by wine fractions rich in phenolic compounds and glycosides. When glycoside fractions were first hydrolyzed, their inhibition was strongly reduced. The stability of glycosidases in red wines was tested, showing a destabilizing effect of β‐glucosidases that was stronger than in white wine. CONCLUSION: The method developed allows measurement of glycosidase activity on p‐nitrophenylglycosides in the presence of colored wine compounds. Comparison of relative glycosidase activity in wines to that in buffer solution under the same conditions can assist in the selection of appropriate aroma‐enhancing enzymes. Copyright © 2009 Society of Chemical Industry     

Phenolics of Vaccinium berries and other fruit crops

The concentrations and profiles of phenolics of selected fruit crops common in the Western diet, including several Vaccinium species, were examined to better understand how these crops may be useful sources of phenolic phytochemicals. Vaccinium fruit had a high phenolic concentration compared to non‐Vaccinium fruit. Some Vaccinium fruit were particularly rich in certain phenolic subgroups, especially anthocyanins and pro‐anthocyanidins. Among the pro‐anthocyanidin oligomers measured using fluorometric and mass spectroscopic detection, the trimers and tetramers were most abundant, while pro‐anthocyanidins with a degree of polymerization greater than 8 were least abundant. As biomedical studies determine which phenolic structures are associated with particular bioactivities, information on the phenolic concentration and profile of selected species will be useful in developing specific uses for fruit crops in human health. Methods were compared to assess the usefulness of simpler versus more sophisticated means of phenolic analysis. The phenolic components of fruit extracts were purified approximately 20‐fold, and not qualitatively altered, by C18 solid‐phase extraction. However, fruit extracts obtained from C18 solid‐phase extraction differed in their relative abundance of phenolic components. Colorimetric and HPLC‐DAD measures of phenolic concentration were correlated (R² = 0.79), as was pro‐anthocyanidin concentration detected fluorometrically and by mass spectrometry (R² = 0.44). Copyright © 2007 Crown in the right of Canada and Society of Chemical Industry     

Diversity in Spoilage Yeast Dekkera/Brettanomyces bruxellensis Isolated from French Red Wine. Assessment During Fermentation of Synthetic Wine Medium

Yeast Brettanomyces bruxellensis is a contaminant found worldwide and is responsible for red wine spoilage due to the development of animal and phenolic off‐odours. During this study, 24 Brettanomyces bruxellenis isolates were obtained from red wine samples from two French wineries and these were discriminated as 23 strains. Nine strains coming from 2 wineries and 4 vintages were cultivated in synthetic wine medium for 1500 hours and they gave nine different behaviours. Four main growth patterns (with different growth steps and durations) and three main different sugar consumption profiles were obtained. Glucose and fructose were not limiting substrates for all strains. The production level of 4‐ethylphenol was found to vary from strain to strain (from 0.350 to 2.773 mg L^?1) and was independent of the biomass concentration. Some strains presented a coupled‐to‐growth production of volatile phenols, others did not. This study showed that different strains of Brettanomyces bruxellensis behaved differently, one from another, under the given conditions taking into consideration several aspects. The results thus demonstrate a large intraspecific diversity.     

Optimisation of the Amido Black assay for determination of the protein content of grape juices and wines

While the heat/chill stability of white wines cannot be predicted from the total protein concentration, this information is useful in assessing the effectiveness of fining treatments. We have adapted the Amido Black assay for use in grape juice and wine. The response of bovine serum albumin (BSA) was similar in water, model wine and model juice. The linear range of the assay (<100 mg l^?1) extends beyond protein concentrations typically found in grape juices and wines. The limit of quantification was 11.1 mg l^?1 for BSA in model wine and 7.6 mg l^?1 in model juice, while the limit of detection was found to be less than 3 mg l^?1 in either solution. In contrast to other methods of protein determination, this assay is not affected by common wine phenolic and pectic compounds or by glutathione. The mean response of BSA was similar in model juice and red and white grape juices. The mean response of BSA in red wine was lower than in white wine and model wine (p < 0.001), and there was considerable variation in response among wines. Protein concentrations determined using this method were reproducible (CV < 10%). This optimised assay can be used to monitor protein levels in grape juices and wines. © 2001 Society of Chemical Industry     

Measurement of total phenolic content in wine using an automatic Folin–Ciocalteu assay method

Measuring the total phenolic content in wine is important in estimating the taste and health benefits of wine. We developed an automatic Folin–Ciocalteu (F‐C) method to reduce processing times (3 min), human errors and waste volume as compared it to the manual method. The gallic acid standard responded linearly up to 5000 μg mL^?1, and the wine dilution series responded linearly between four‐ and sixteenfold dilutions. Anthocyanins showed slower reaction rate compared with wine, gallic acid and quercetin, while ascorbic acid showed the fastest rate. Fructose and glucose at the 10% level showed approximately 8% interference in port wines, and the interference was thought to be negligible in most dry wines containing <1% sugar. Total phenolic contents ranged between 1600 and 3300 μg mL^?1 by the automatic method and were approximately 20% less than those by the manual method, except in pink wines which was nearly identical. The regression analysis of the phenolic contents showed a very linear relationship between the methods (r² = 0.97***). This automatic method was thought to be efficiently adopted in wine testing laboratories as a fast and reproducible assay.     

Assessing the Potential Content of Ethyl Carbamate in White,Red, and Rosé Wines as a Key Factor for Pursuing Urea Degradation by Purified Acid Urease

The ethyl carbamate (EC) content of a wine after a given temperature‐time storage was theoretically predicted from the potential concentration of ethyl carbamate (PEC), as determined via an accelerated EC formation test. Such information was used to decide whether an enzymatic treatment was needed to reduce the wine urea level before bottling/aging. To this end, 6 white, red, and rosé wines, manufactured in Italy as such or enriched with urea, were tested for their PEC content either before or after enzymatic treatment using a purified acid urease preparation derived from Lactobacillus fermentum. The treatment was severely affected by the total phenolic content (TP) of the wine, the estimated pseudo‐first‐order kinetic rate constant for NH₃ formation reducing by a factor of approximately 2000 as the TP increased from 0 to 1.64 g L^‐1. Such a sensitivity to TP was by far greater than that pertaining to a killed cell‐based enzyme preparation used previously. Urea hydrolysis was successful at reducing EC concentration in wines with low levels of TP and other EC precursors.     

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..     

Chemical and Structural Analysis of Fibre and Core Tissues from Flax

Samples of flax ( Linum usitatissimum ) stems from the cultivars ‘Natasja’ and ‘Ariane’ were separated into fibre and core fractions and analysed by gas–liquid chromatographic methods, ¹³C CPMAS NMR spectrometry, histochemistry, electron microscopy and UV absorption microspectrophotometry to assist in determining the structure and composition of these cell walls in relation to quality and utilisation. Analyses from chromatography and NMR gave similar results for carbohydrate and phenolic constituents in various samples and in the lower, more mature regions of the stem. Amounts of uronic acids and xylose were lower while amounts of mannose, galactose and glucose were higher in fibre vs core fractions. Quantities of phenolic constituents were significantly higher in the core than the fibre, with groups representative of both guaiacyl and syringyl lignins; amounts of phenolic acids were low. NMR showed a low intensity signal for aromatics in fibre, and it is possible that such signals arise from compounds in the cuticle rather than the fibre. Microscopic studies indicated that aromatic constituents were present in core cell walls, cuticle of the epidermis, and cell corners and middle lamellae of some regions within the fibre tissues. The lignin in fibre appeared to be of the guaiacyl type and may be too low in concentration to be unambiguously detected by NMR. Aromatic compounds were not observed in the epidermis or parenchyma cell walls. Similar analyses of dew-retted (unscutched) samples indicated that core tissues were mostly unchanged from unretted samples. Retted fibre tissues still contained lignified cell corners and middle lamellae in some regions. The cuticle, which was associated with retted fibres, was not degraded by dew-retting fungi. Fungi removed interfibre materials in some places and at times degraded the secondary wall near the cell lumen of fibre cells. Results indicate that microspectrophotometry and histochemistry are useful to identify the location and type of aromatics in fibre cell walls.     

Extraction,identification and enzymatic synthesis of acylated derivatives of anthocyanins from jaboticaba (Myrciaria cauliflora) fruits

Polyphenols were extracted from the skin of jabuticaba fruits (Myrciaria cauliflora). Their total concentration and in vitro antioxidant activity were analysed by the DPPH and ABTS methods. The corresponding results (dry basis) were 1290 mg gallic acid equivalent (GAE)?(100 g)^?1, 98% of DPPH radical inhibition and 120 μm TEAC?g^?1 (ABTS method). All these values are at least as higher as average values reported in the literature for other fruits. A more specific analysis of the fractions of phenolic compounds was also performed by HPLC‐MS. Ellagic acid, quercetin, rutin, delphinidin‐3‐glucoside and cyanidin‐3‐glucoside were the main compounds detected; the latter two were the most abundant. The crude extract was subjected to enzymatic acylation assays in order to synthesise new esters with new potential techno‐functionalities. Palmitic acid was used as acyl donor and lipase B of Candida antactica (CALB) as biocatalyst. HPLC‐MS evidenced the formation of palmitic monoesters in connection with the delphinidin‐3‐glucoside and cyanidin‐3‐glucoside fractions.     

Isolation and Identification of Phenolic Antioxidants in Black Rice Bran

Black rice bran contains phenolic compounds of a high antioxidant activity. In this study, the 40% acetone extract of black rice bran was sequentially fractionated to obtain 5 fractions. Out of the 5 fractions, ethyl acetate fraction was subfractionated using the Sephadex LH‐20 chromatography. The antioxidant activity of phenolic compounds in the extracts was investigated by 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical assay, 2,2‐azino‐bis‐(3‐ethylenebenzothiozoline‐6‐sulfonic acid) (ABTS) radical cation assay, reducing power. The subfraction 2 from ethyl acetate fraction had the highest total phenolic contents (TPC) (816.0 μg/mg) and the lowest EC₅₀ values (47.8 μg/mL for DPPH radical assay, 112.8 μg/mL for ABTS radical cation assay, and 49.2 μg/mL for reducing power). These results were 3.1, 1.3, and 2.6 times lower than those of butylated hydroxytoluene (BHT), respectively. At a concentration of 100 μg/mL, the antioxidant activity and TPC of various extracts was closely correlated, with correlation coefficients (R²) higher than 0.86. The major phenolic acid in subfraction 2 was identified as ferulic acid (178.3 μg/mg) by HPLC and LC‐ESI/MS/MS analyses. Our finding identified ferulic acid as a major phenolic compound in black rice bran, and supports the potential use of black rice bran as a natural source of antioxidant.     

Extracts of Mexican Oregano (<Emphasis Type="Italic">Lippia berlandieri</Emphasis> Schauer) with Antioxidant and Antimicrobial Activity

Antimicrobial activity of fractions obtained from Mexican oregano (Lippia berlandieri Schauer) chloroform extract was tested by growth inhibition against Escherichia coli, Staphylococcus aureus and Bacillus cereus, and antioxidant capacity was tested by inhibition of linoleic acid oxidation. Fractions were obtained by differences in polarity or structure (phenolic and non-phenolic fraction). Gram-positive organisms were more susceptible to Mexican oregano extracts. Fraction 3 (by polarity) and phenolic fractions I, II, III, IV and V were the extracts with higher antimicrobial activity. The non-phenolic fraction had effect against B. cereus. Polarity fraction 5 and phenolic Fraction II had a high antioxidant capacity; a 0.08% concentration of fraction 5 had a similar effect as butylated hydroxytoluene at 0.01% concentration. Fractions of Mexican oregano with different polarity and functional groups had antioxidant and antimicrobial activity and can be used in a variety of applications.     

Influence of wine turbidity on the accumulation of biogenic amines during aging

In this work the concentration of biogenic amines in filtered and unfiltered wine during aging in oak barrels was studied. Red wine from Merlot grapes was used. The wine remained for 243 days in barrels of American oak (Quercus alba) and French oak (Quercus sessilis) from the Allier and Nevers regions. Results showed that the different degree of wine turbidity did not have any influence on the accumulation of biogenic amines during the aging period. Histamine and tyramine were degraded at the end of aging; however, the concentration of histamine in both matured wines was higher than 8 mg l^?1, which could be a toxic danger to consumers. Putrescine and cadaverine were formed during aging and were not degraded. Phenylethylamine + spermidine were formed, above all, towards the end of the aging period, and the concentration of spermine did not show any appreciable variation. Copyright © 2004 Society of Chemical Industry     

Wine composition plays an important role in the control of carcinogenic precursor formation by Lactobacillus hilgardii X1B

BACKGROUND: Lactobacillus hilgardii, a wine lactic acid bacterium, is able to use arginine, through the arginine deiminase pathway with the formation of citrulline, a precursor of the carcinogen ethyl carbamate. The influence of different Argentine wine varieties (Merlot, Cabernet Sauvignon and Malbec), on bacterial growth and arginine metabolism was examined. Furthermore, the effect of different components normally present in wines on the enzyme activities of the arginine deiminase system was determined. RESULTS: Malbec wine under all conditions assayed (33, 50 and 100% supplemented wine:basal media) showed higher arginine consumption and citrulline production than the other wines, as well as the highest bacterial growth and survival of Lactobacillus hilgardii X₁B. Glucose and L ‐malic inhibited both arginine deiminase enzymes while fructose and citric acid only inhibited arginine deiminase. The red wines assayed in this study had different composition, and this is an explanation for the different behavior of the bacterium. CONCLUSION: The highest citrulline production in Malbec wine could be correlated with its lower concentrations of glucose, fructose, citric and phenolic acid than the other wines. Therefore, a wine with lower concentration of these sugars and acids could be dangerous due to the formation of ethyl carbamate precursors. Copyright © 2012 Society of Chemical Industry     

Effect of high pressure treatments on the physicochemical properties of a sulphur dioxide-free red wine

The application of high hydrostatic pressure (HHP) in winemaking for substitution of the use of sulphur dioxide is still at a very early stage of development, since knowledge about the effect on physicochemical and sensorial characteristics of the wine during storage is very scarce. In this work, the evolution of colour, antioxidant activity and total phenolic compounds of SO₂-free red wines treated by HHP and aged in bottles was followed for 12 months. The pressurised wines were compared with wine samples prepared with addition of 40 ppm of SO₂ and without any of these two treatments. After 12 months, the pressurised wines presented higher values of CIELab parameters (a^∗, b^∗, and L^∗) and a lower monomeric anthocyanin content (45–61%) when compared to the unpressurised ones. The pressurised wines showed also a better global sensorial assessment, with the pressure treatments imparting aged-like characteristics to the wines. The wine deposits of pressurised wines had higher total phenolic content, namely proanthocyanidins (3- to 10-fold). The results demonstrate that HHP can influence long term red wine physicochemical and sensorial characteristics, hypothesised to be due to an increase of condensation reactions of phenolic compounds, forming compounds with higher degree of polymerisation that became insoluble in wine along storage.     

Stability of Individual Phenolic Compounds and Antioxidant Activity During Storage of a Red Wine Powder

The addition of maltodextrin DE 10 to red wine (Cabernet Sauvignon) followed by freeze-drying allowed to obtain a free-flowing (dealcoholized) wine powder (WP) having a phenolic concentration about 3.6 times higher than the original liquid red wine. The powder, having a water activity (a _w) of 0.053 and 0.330 was stored at 28 °C and 38 °C and the content of ten different phenolic compounds was determined by HPLC. Caftaric acid, quercetin 3-glucoside, caffeic acid, gallic acid and resveratrol contents in the WP stored at 28 °C and 38 °C, remained almost constant during 70 days of storage, while epicatechin gallate, catechin, malvidin 3-G and epicatechin showed slight losses (about 15–25 %) during storage. On the contrary, epigallocatechin experienced a strong loss of concentration (around 61 % loss) during storage at the same conditions. A moderate decrease of antioxidant activity, determined by free radical scavenging capacity of the 2,2-diphenyl-1-picrylhydrazyl free radical (DPPH*) and ferric reducing antioxidant power (FRAP) was observed along storage. This decrease was more important at higher temperature (38 °C) and higher a _w (0.33). These results would allow the feasibility of using this WP as a healthy ingredient in alcohol-free powder drinks.     

Preliminary studies on acidity-astringency interactions in model solutions and wines

Intensity of astringency in model solutions and wines varying in total acid and total phenols was evaluated by paired comparisons by 10 trained judges. Model solutions consisted of tannic (500, 1000, 2000 mg litre^?1) and tartaric (0, 2, 4, 6 g litre^?1) acids dissolved in aqueous solutions of ethanol (120 ml litre^?1) and sucrose (5 g litre^?1). Wine solutions were prepared by addition of citric acid (0, 0.5, 1, 2, 3 g litre^?1 as tartaric acid) to a high phenol-red wine (2645 mg litre^?1 GAE) and a moderate phenol-white wine (800 mg litre^?1 GAE). At all three levels of tannic acid, astringency of model solutions increased significantly (P<0.001) with tartaric acid concentration. Astringency of white wine also increased significantly (P<0.05) with citric acid concentration. A negative linear relation was found between relative astringency and pH at a given tannin level for both model solutions and white wine. As pH was reduced, more phenolic molecules were in the phenol form thereby increasing the likelihood of hydrogen bonding between hydroxyl groups of wine tannins and ketoimide groups of mouth proteins. The preliminary hypothesis that hydrogen bonding is the main reaction involved in the formation of protein-tannin complexes resulting in the sensation of astringency was reinforced.