Red Grape Varieties Research Articles

Characterization of seed proanthocyanidins of thirty-two red and white hybrid grape varieties

Grape seed extracts are known for their beneficial effects on health and on cardiovascular diseases due to antioxidant activity and the free radical-scavenging properties of proanthocyanidins (PAs). Moreover, grape seed tannins are used in oenology as additives to improve the organoleptic characteristics of wines, and for the clarification of must and wines. PAs in seed extract of 32 hybrid and three V. vinifera grape varieties were characterized by MALDI-TOF mass spectrometry. Signals of 148 compounds were identified as [M+H]+, [M+Na]+ and [M+K]+ adducts of B-type and A-type PAs formed from catechin/epicatechin subunits up to undecamers and with galloylation degree 0-7. The number-average molecular weight (Mn) of the samples, a parameter correlated with the molecular weight of polymers, and the polyphenolic content of extract, were also determined. Profiles of the hybrid grape varieties were compared with those of three V. vinifera samples studied as references. 'Terzi 108-6' showed high content of antioxidant polyphenols and 'Seyve Villard 12-390' higher content of higher oligomers. These two grape varieties are therefore potentially very interesting as sources of antioxidants and tannins for nutraceutical and oenological uses.

Characterization of Non-Anthocyanic Flavonoids in Some Hybrid Red Grape Extracts Potentially Interesting for Industrial Uses.

Previous studies showed that hybrid grapes often have qualitatively and quantitatively higher polyphenolic contents than the common V. vinifera grape varieties. In general, these compounds are studied for grape chemotaxonomy and for nutraceutical purposes due to their relevant antioxidant activity. Non-anthocyanic flavonoid composition of five red hybrid grape varieties produced by crossing of V. vinifera, V. aestivalis, V. cinerea, V. berlandieri, V. labrusca, V. lincecumii, and V. rupestris were studied by liquid chromatography/high-resolution mass spectrometry. Thirty-one compounds were identified, including methylnaringenin, a tetrahydroxy-dimethoxyflavanone-hexoside, two flavonols (quercetin and a pentahydroxyflavone isomer), 20 glycoside flavonols (four quercetin, two myricetin, two kaempferol, three isorhamnetin, one laricitrin, two syringetin, one kaempferide and two dihydroflavonol derivatives; myricetin-glucoside-glucuronide; myricetin-diglucoside; syringetin-dihexoside), three flavan-3-ols (−)-epicatechin, (+)-catechin, (−)-epicatechin gallate) and four proantocyanidins (procyanidin B1, procyanidin B2, procyanidin B3 or B4/B5, procyanidin T2 or T3/T4/C1). Seibel 19881, Seyve Villard 12-347 and Seyve Villard 29-399 were particularly rich in polyphenols. These findings emphasize that these grapes are especially interesting for the production of antioxidant extracts for nutraceutical and pharmaceutical uses.

Adaptability of some French red grape varieties cultivated at two different Portuguese terroirs: Comparative analysis with two Portuguese red grape varieties using physicochemical and phenolic parameters

In the last year's, several French grape varieties have been introduced in different world wine regions, increasing their representation in the world. Consequently, it is important to analyze the adaptability of several red grape varieties from French origin to the other specific ‘terroirs’ and compare their characteristics with native grape varieties. Thus, the aim of this study was to evaluate the physicochemical and phenolic composition of five French red grape varieties and two Portuguese red grape varieties grown at two different Portuguese wine regions. In general, French (except ‘Alicante Bouschet’ grape variety) and Portuguese red grape varieties collected in the vineyard located in ‘Dão’ wine region had higher positive physicochemical characteristics, especially for estimated alcohol degree and titratable acidity. Regarding the phenolic composition, French grape varieties showed significantly higher values of total phenols and flavonoid compounds, especially for the grape samples collected in the vineyard located in ‘Dão’ region. Thus, for example ‘Alicante Bouschet’ grape variety showed the highest values for total phenolic (global average value from 0.636 to 0.894mgg−1 of berry) and flavonoid compounds (global average value from 0.584 to 0.834mgg−1 of berry). However, for total anthocyanins it was clear that the two Portuguese grape varieties studied (‘Touriga Nacional’ and ‘Tinta Roriz’) showed significantly highest values independently of the wine region considered (global average value ranged from 0.603 to 0.785mgg−1 of berry). Similar tendency was also confirmed by significantly highest global average values for the sum of the glycosylated derivatives, where the values ranged from 0.389 to 0.539mgg−1 of berry, for the two Portuguese grape varieties considered.

Maceration affects mineral composition and pH of wines

Mineral composition of wines is affected by many ecological and technological factors. These variables are mostly discussed focusing on certification of origin and human health. This paper gives data on possible changes in mineral composition and pH of wines due to 4 hours skin maceration (1st trial) and fermentation sur marc (2nd trial). Experimental site is situated on acidic sandy soil in middle east Hungary. The variety collection was established in 2003 with own rooted planting material in 3x1 m spacing, trained for single curtain trainingsystem. Mineral composition of wines was determined with ThermoFischer Scientific iCAP 6300 ICP-OES, pH was measured with pH10pen (VWR International) in field, and with SevenEasyTM pH meter (Mettler Toledo) in laboratory. 1st trial with 9 PIWI white wine grape varieties pointed to demonstrate effects of skin maceration, which is abundantly used to elevate aroma content. 2nd trial with the use of ‘Medina’ red PIWI grape variety aimed to demonstrate effects of double pasta skin maceration in rose and red wine technology. Data of 1st trial show, that K, Cu, Mn and P respective increase with skin maceration, despite Fe show considerable decrease. Data of 2nd trial show, that K, Mg, Mn, P, Sr and B increase with longer skin contact and higher fermentation temperature, despite Fe and Ba decrease with this technology. In regard to pH, data show, that skin maceration and fermentation sur marc increase K content with about 30-70% respectively, withstanding that pH also increase with a considerable 0,4-0,5 value. K content can be higher in the end product, despite to earlier higher level of tartrate formation. An attention should be driven to lower level of tartaric acid and consequently higher pH characteristic for wines produced with the application of skin maceration or fermentation sur marc.

Response of ungrafted rootstocks and rootstocks grafted with wine grape varieties (Vitis sp.) to ‘lime-induced chlorosis’

ABSTRACTThe ungrafted rootstocks 41B, 1103P, 110R and 140Ru, the grafted combinations of 41B, 1103P and 110R with Xinomavro (one of the most important red wine grape varieties in Greece), as well as those of 1103P, 110R and 140Ru with Chardonnay, were evaluated for 'lime-induced chlorosis' tolerance by growing them with a) basic nutrient solution (BNS), b) BNS + 10 mM bicarbonate, c) BNS without iron (Fe) and d) BNS without zinc (Zn), in hydroponics. The ungrafted 140Ru followed by 41B under high bicarbonate presented the lowest degree of chlorosis; however only 41B presented non-differentiated biomass production and root/shoot ratio. Chlorotic symptoms in combination with plant growth parameters should be used as a tool for grapevine rootstock lime-tolerance screening whereas leaf Fe concentration and root ferric chelate reductase (FCR) activity should not. Lime-stress conditions affected plant mineral nutrition by depressing leaf nitrogen (N), phosphorus (P), calcium (Ca), magnesium (Mg) and increasing potassium (K), and zinc (Zn).

Aroma Fingerprint Characterisation of La Mancha Red Wines

In the present study, Rojal, Moravia Dulce and Tortosi wines were elaborated across four harvests (2006 to 2009) from minority red grape varieties cultivated in the La Mancha region of Spain. Wines were studied by instrumental and sensory analysis to determine the influence of grape variety on the aroma of the wine. Aroma compounds were isolated by solid phase extraction (SPE) to later be analysed using gas chromatography–mass spectrometry (GC/MS). The odour activity values (OAVs) for the different compounds were classified into seven odorant series that describe the aroma profile of these wines (1: fruity, 2: floral, 3: green/fresh, 4: sweet, 5: spice, 6: fatty, and 7: other odours). The total intensities of every aromatic series were calculated as sum of the OAV of each one of the compounds assigned to this series. All wines showed the same sequence, with the highest aroma contribution being those of the sweet and fruity series, followed by fatty. The sensory profile of Rojal, Moravia Dulce and Tortosi wines was evaluated by experienced wine tasters using a non-structured scale. The panellists founded several differences between their sensory profiles. This study provides a complete aromatic characterisation of these wines.

Localization of free and bound aromatic compounds among skin, juice and pulp fractions some grape varieties

The localization and distribution of free and glycosidically-bound aroma compounds among the skin, pulp and juice of three red grape varieties ( Vitis vinifera L. var. Monastrell, Cabernet Sauvignon and Tempranillo) have been studied. An Amberlite XAD-2 column was utilized to separate and extract the free aroma compounds and the glycosidically-bound aromatic compounds. A commercial enzymatic preparation (Pectinol C) was used to release the bound aroma compounds. Gas chromatography and gas chromatography-mass spectrometry were used for the analysis of the compounds. The results showed that the major compounds in these varieties were alcohols and aldehydes, the skin being the fraction with the largest quantities of aromatic compounds. After the enzymatic hydrolysis. the analysis of the liberated compounds showed that they were mainly alcohols and monoterpenes. Two monoterpenes that did not appear as free aroma compounds could he found.

Phenolic Compounds and Bioactivity of Healthy and Infected Grapevine Leaf Extracts from Red Varieties Merlot and Vranac (Vitis vinifera L.).

We investigated the phenolic composition, radical scavenging activity, and antimicrobial activity of grapevine leaf extracts from two red grape varieties, Vranac and Merlot (Vitis vinifera L.). The extracts were prepared from healthy grapevine leaves and those infected by Plasmopara viticola (downy mildew). The phenolic composition of the grapevine leaf extracts was determined using spectrophotometric assays and reverse-phase high performance liquid chromatography (RP-HPLC). The radical scavenging activity of grapevine leaf extracts was determined by the 2,2-diphenyl-1-picrylhydrazyl assay, and their antimicrobial activity was determined by microwell dilution tests. The total phenolic content was higher in healthy grapevine leaf extracts than in infected grapevine leaf extracts. The RP-HPLC analysis detected significant amounts of flavonols, phenolic acids, and flavan-3-ols, and small amounts of stilbenes in the grapevine leaf extracts. Compared with the infected grapevine leaf extracts, the healthy grapevine leaf extracts were richer in flavonols, phenolic acids, and flavan-3-ols, but had lower stilbenes contents. All extracts showed strong free radical scavenging activity, which was strongly correlated with the total phenolic content (R(2) = 0.978). The extracts showed a stronger antimicrobial activity towards Gram-positive bacterial strains than towards Gram-negative bacterial strains and yeast. The phenolic compounds in grapevine leaves were responsible for their strong radical scavenging and antimicrobial activities. Together, these results demonstrate that grapevine leaves have high nutritional value and can be used as a fresh food and to prepare extracts that can be used as additives in food and medicines.

Comparison of the yeast microbiota of different varieties of cool-climate grapes by PCR-RAPD

The yeast microbiota occurring on different varieties of grapes grown in cool-climate is not completely researched. Therefore, its identification is important to research. On the other hand, yeasts occurring in these fruits can be potentially used as starter cultures to obtain particularly demanded features in the production of wine. In addition, rapid methods for yeast identification allow to eliminate the contamination with pathogenic yeasts, which could cause the loss of wine production. The aim of the study was to isolate and identify the yeasts occurring on the surface of the different varieties of white and red grapes, grown in cool-climate of Poland. Also, the aim was to compare the qualitative and quantitative composition of yeasts on the tested grapes. The 84 cultures of yeasts were isolated, that were initially macroscopic and microscopic analyzed and the purity of cultures was rated on the WL medium. Identification of yeasts by PCR-RAPD was carried using the M13 primer. In the PCR-RFLP method ITS1 and ITS4 primers, as well as restriction enzymes HhaI, HinfI, HaeIII, were used. Preliminary identification of yeasts by standard methods produced results very different from the results obtained by molecular methods. Among the isolated microorganisms yeasts were dominating, but bacteria and molds were also present. Using the PCR-RAPD method most strains of yeasts were identified. Yeast microflora of different varieties of white and red grapes was very similar as the same species of yeasts were identified. Yeasts of the genus Saccharomyces were present in all varieties of grapes. The Rhodotorula mucilaginosa, Saccharomyces cerevisiae, Metschnikowia pulcherrima, Rhodotorula minuta, Pichia kluyveri, Hanseniaspora uvarum and Rhodotorula mucilaginosa were identified by PCR-RAPD. 4 of the 33 tested strains of yeasts were identified by PCR-RFLP. By PCR-RAPD only Hanseniaspora uvarum was identified. The quantity and quality of microorganisms living on the surface of grape fruits is very important for the process of winemaking. Yeasts influence the course of alcoholic fermentation, the flavor, aroma, and thus the quality of the produced wine. To a large extent their presence depends on the condition of the surface of the fruit. Many researchers reported significant differences between yeast microflora in grapes of Mediterranean and cool-climate vineyards. As they are expected to affect the final wine properties precise researching of the microflora of cool-climate grapes may lead to the isolation of new species of yeasts and thus the wines with unique characteristics can be obtained.

Development of a high-performance liquid chromatography method based on a core–shell column approach for the rapid determination of multiclass polyphenols in grape pomaces

A rapid and economically affordable reverse-phase chromatographic approach based on a core–shell column with high-performance liquid chromatography multi-wavelength detector (HPLC-MWD) is proposed for the quantification and quality control of multiclass polyphenols (PPs). The separation of 20 relevant polyphenols from grape pomace extracts (GPEs) was achieved in less than 12min by using a Kinetex C18 column (3.0mm×100mm, 2.6μm) with a gradient system of ultrapure water (0.1% formic acid) and acetonitrile, a temperature of 35°C and a flow rate of 0.8mLmin−1. The maximum backpressure reached was 327bar, meaning the developed method is adequate for standard HPLC instruments. The applicability of the method was demonstrated by the determination of PPs in GPEs of different red grape varieties. Cabernet Sauvignon GPE showed the highest content of studied PPs (9804.2μgg−1GPE) followed by Bonarda GPE (7302.0μgg−1GPE). Besides the methodological development for a high throughput routine quality control of GPEs, this is the first report of PPs content for Bonarda and Aspirant Bouchet GPE, so the results add knowledge for these grape varieties cultivated in Argentina.

Effects of Different Crop Load of Vine and Length of Maceration on Polyphenolic Content of Vranac Cultivar

Polyphenols have a significant impact on the quality of the red wine grape varieties. Certain amphelotechnical measures and technological pro­cesses affect directly the content of polyphenols in grapes and wine. The aim of the study was to investigate the influence of different crop load of the vine and length of maceration of grape pomace on polyphenolic content and sensory properties of Vranac cultivar which represents the leading red variety in the Republic of Macedonia. Studied the different crop load of the vine (control, variant 1 with a 25% reduction of the yield, variant 2 - 35% reduction of the yield and a variant of 3- 50% reduction of the yield) as well as different times of maceration (7days and 14 days) on the phenolic composition of wine. Test results showed a positive correlation between the crop load and the content of total polyphenols, ie, reducing the number of bunches per vine comes to an increase in the content of total polyphenols in wine as well as length of maceration achieves the same correlation.

Automatic grape bunch detection in vineyards with an SVM classifier

Precise yield estimation in vineyards using image processing techniques has only been demonstrated conceptually on a small scale. Expanding this scale requires significant computational power where, by necessity, only small parts of the images of vines contain useful features. This paper introduces an image processing algorithm combining colour and texture information and the use of a support vector machine, to accelerate fruit detection by isolating and counting bunches in images. Experiments carried out on two varieties of red grapes (Shiraz and Cabernet Sauvignon) demonstrate an accuracy of 88.0% and recall of 91.6%. This method is also shown to remove the restriction on the field of view and background which plagued existing methods and is a first step towards precise and reliable yield estimation on a large scale.

Green extraction of antioxidants from different varieties of red grape pomace.

The extraction yield, phenolic content, anthocyanin content and antioxidant activity of extracts from different varieties of red grapes, Cabernet Sauvignon, Merlot, Petit Verdot, Syrah, Tempranillo and Tintilla, using pressurized green solvents have been analyzed. Two techniques were studied and compared: supercritical fluid extraction (SFE) with CO2 + 20% ethanol and pressurized liquid extraction (PLE) with either ethanol, water or an ethanol/water mixture as the extraction solvents. The Petit Verdot variety allowed the highest global and phenolic yield, and antioxidant activity. The best conditios for PLE obtained from the experimental design and kinetic study were 50% ethanol/water as the pressurized solvent at 90 bar, 120 °C, a flow rate of 5 g/min and, an extraction time of 90 min. A statistical analysis of variance has been performed and it was found that temperature is the only variable that has a statistical influence on the extraction yield. The antioxidant activity levels of the extracts are very promising and they are similar to those obtained with the antioxidant tocopherol.

Influence of fruit maturity at harvest on the intensity of smoke taint in wine.

Bushfire smoke can affect the composition and sensory properties of grapes and wines, in some cases leading to wines which exhibit undesirable “smoky”, “ashy” and “medicinal” characters. This study investigated the extent to which fruit maturity (i.e., ripeness) influences the perception of smoke taint in wine. Two white grape varieties (Chardonnay and Sauvignon Blanc) and two red grape varieties (Merlot and Shiraz) were exposed to smoke under experimental conditions, at approximately seven days post-veraison. Fruit was then harvested at two levels of maturity: Harvest A, when total soluble solids were 16–20 °Brix, i.e., the berry ripeness typically required for production of sparkling or light-bodied wines; and Harvest B, when total soluble solids were 22–25 °Brix, i.e., the berry ripeness typically required for production of full-bodied wines. The intensity of smoke taint in resulting wines was found to be influenced by fruit maturity, but differed between grape varieties. Smoke-related sensory attributes were apparent in Sauvignon Blanc wine made from early-harvested fruit and in Chardonnay wine made from late-harvested fruit, only; whereas Merlot and Shiraz wines exhibited smoke taint irrespective of fruit maturity. Smoke-derived volatile phenols, and various alcohols, esters and acids, were also quantified to determine the impact of smoke exposure and fruit maturity respectively, on wine composition.

Monitoring trans-Resveratrol in Grape Berry Skins During Ripening and in Corresponding Wines by HPLC.

Trans-resveratrol (3,5,4'-trihydroxy-trans-stilbene) is naturally present in the skin of grapes and therefore is expected to occur in grape products. Recently, there has been a renewal of interest in wine as medical treatment for various disorders. In this study, berry skins of five red grape varieties were analysed at weekly intervals for trans-resveratrol production, during 2012 and 2013 harvest. The obtained wines were also evaluated. Quantification of trans-resveratrol in grape skin extracts and wines was carried out by high-performance liquid chromatography. Favourable viticultural climate during harvest in 2012 resulted in a higher content of trans-resveratrol. The highest trans-resveratrol content was in Pinot Noir and Feteasca Neagra grape varieties, both in berry skins and wines, while the lowest amounts were identified in Cabernet Sauvignon variety. We can conclude that there was a significant correlation between the content of trans-resveratrol in grape skins and that in the respective wine.

Yeast contribution to melatonin, melatonin isomers and tryptophan ethyl ester during alcoholic fermentation of grape musts.

Melatonin (MEL) has been found in some medicinal and food plants, including grapevine, a commodity of particular interest for the production of wine, a beverage of economic relevance. It has also been suggested that MEL in wine may, at least in part, contribute to the health-promoting properties attributed to this beverage and, possibly, to other traditional Mediterranean foodstuffs. After a preliminary screening of 9 yeast strains in laboratory medium, three selected strains (Saccharomyces cerevisiae EC1118, Torulaspora delbrueckii CBS1146(T) and Zygosaccharomyces bailii ATCC36947(T) ) were inoculated in experimental musts obtained from 2 white (Moscato and Chardonnay) and 2 red (Croatina and Merlot) grape varieties. The production of MEL, melatonin isomers (MIs) and tryptophan ethyl ester (TEE) was monitored during the alcoholic fermentation. The screening showed that the three investigated strains produced the highest concentrations of MEL and two MIs in optimal growth conditions. However, MEL and MIs were not produced in oenological conditions, but the three strains synthesized high concentrations of a new MI and TEE in musts.

Influence of wine region provenance on phenolic composition, antioxidant capacity and radical scavenger activity of traditional Portuguese red grape varieties

The introduction and spread of world-renowned varieties has caused a massive loss of indigenous grapevine varieties traditionally grown in various wine countries. In this point of view, Portugal is no exception to this situation. Thus, the aim of this study was to analyze seven traditional Portuguese red grape varieties cultivated at the same time in two wine regions of Portugal in order to determine the potential influence of these two provenances on several phenolic and antioxidant capacity parameters. Taking into account the general phenolic parameters, the highest values were found for the grape varieties cultivated in ‘Dao’ region (a global average value of 0.640 and 0.526 mg/g berry for total phenolic compounds and total anthocyanins, respectively). Regarding the values of total antioxidant capacity and superoxide radical scavenger activity (using SRSA method), a similar trend was observed (a global average value of 6.57 and 5.92 µmol trolox/g berry for antioxidant capacity, using ABTS and DPPH methods, respectively). However, for non-flavonoid phenols, the highest values were quantified in the samples harvested from ‘Douro’ region (a global average value of 0.047 mg/g berry). With this work, it was clear that the variability of the results obtained were determined by the genetic and also by environmental factors.

Distinctive Anthocyanin Accumulation Responses to Temperature and Natural UV Radiation of Two Field-Grown Vitis vinifera L. Cultivars

The responses of two red grape varieties, Bovale Grande (syn. Carignan) and Cannonau (syn. Grenache), to temperature and natural UV radiation were studied in a three-years field experiment conducted in Sardinia (Italy), under Mediterranean climate conditions. Vines were covered with plastic films with different transmittances to UV radiation and compared to uncovered controls. Light intensity and spectral composition at the fruit zone were monitored and berry skin temperature was recorded from veraison. Total skin anthocyanin content (TSA) and composition indicated positive but inconsistent effects of natural UV light. Elevated temperatures induced alterations to a greater extent, decreasing TSA and increasing the degree of derivatives acylation. In Cannonau total soluble solids increases were not followed by increasing TSA as in Bovale Grande, due to both lower phenolic potential and higher sensitivity to permanence of high temperatures. Multi linear regression analysis tested the effects of different ranges of temperature as source of variation on anthocyanin accumulation patterns. To estimate the thermal time for anthocyanin accumulation, the use of normal heat hours model had benefit from the addition of predictor variables that take into account the permanence of high (>35 °C) and low (<15 °C and <17 °C) temperatures during ripening.

Wine tartrate stabilization by different levels of cation exchange resin treatments: impact on chemical composition, phenolic profile and organoleptic properties of red wines

The aim of this work was to evaluate the impact of cation exchange resin, on tartrate stabilization, chemical composition, general phenolic composition, individual anthocyanin and different proanthocyanidin fraction content of a red wine made from a mixture of three Portuguese red grape varieties. Additionally, the influence of this tartrate stabilization process on organolpetic properties was another aim of this work. The cation exchanged red wines were mixed in different proportions with the untreated red wine. The results showed that the application of a cation exchange resin used was useful to adjust the pH and total acidity and revealed a good capacity to retain potassium and calcium. In addition, the cation exchange resin treatment caused a significant decrease in the contents of individual anthocyanins well as in the different fractions of proanthocyanidins (especially in monomeric fraction). Finally, considering the organoleptic properties, the most highly evaluated wine, especially considering taste parameters, was the control wine. These results confirm that cation exchange is an interesting in red winemaking to improve tartaric stability, but at same time it is important analyze potential effects on phenolic content and organoleptic properties of red wines.

Molecular and oenological characterization of Touriga Nacional non-Saccharomyces yeasts.

The aim of this study was to evaluate non-Saccharomyces yeasts isolated from spontaneous fermenting musts of Touriga Nacional (TN), one of the most important Portuguese red grape variety, to improve and diversify TN wines. Two hundred and seventy nine isolates were assigned to 11 yeast species by conventional molecular and growth tests. Starmerella bacillaris was the most frequently detected yeast species, followed by Hanseniaspora guilliermondii and Hanseniaspora uvarum. Twenty-three isolates from 10 species were selected for oenological study, namely fermentation performance, physicochemical and quantitative descriptive sensory analysis of the wines produced. A significant species effect was observed for most of the variables evaluated, some species generating wines with quite interesting aromas. Candida diversa and S.bacillaris isolates produced wines with higher overall quality, higher balance and more intense and diverse aroma. Furthermore, S.bacillaris isolates generated wines with enhanced TN typical aroma, such as bergamot, violet and rock-rose, and were thus regarded as the most promising for improving TN wines. This study revealed the diversity of wine aroma profiles generated by non-Saccharomyces yeast isolates. This knowledge is particularly important given the growing trend from industry to use non-Saccharomyces yeasts as a tool for improving and diversifying the sensory characteristics of wine.