Phenolic profile of Macedonian red wines

Wine possess a variety of recognized beneficial effects on human health, such as anti-inflammatory, antimicrobial and anti-aging effects, as well as prevention of cardiovascular diseases. All these effects are due to the high content of phenolic compounds, such as stilbenes, anthocyanins, flavonols, flavan-3-ols and phenolic acids. In this study, red wines from Vranec, Cabernet Sauvignon and Merlot varieties (V. Vinifera L.) have been analysed using high-performance liquid chromatography coupled with diode array detector and on line mass spectrometry (HPLC-DAD–ESI-MS and MS/MS) in order to determine their phenolic profile. All wines presented a complex phenolic profile represented by anthocyanins, pyranoanthocyanins, flavonols, hydroxycinnamic acids and their derivatives, stilbenes, gallic acid and flavan-3-ols. Vranec wine, which is characterized with deep red colour, showed highest concentration of all phenolic families compared to Cabernet Sauvignon and Merlot wines, indicating the important role of variety in differentiation of phenolic composition

Assay of the phenolic profile of Merlot wines from Macedonia: Effect of maceration time, storage, SO2 and temperature of storage

Spectrophotometric assays of total anthocyanins, total phenolics, total catechins, total flavonoids, color intesity and hue were performed on Merlot wines obtained with 3, 6 and 10 days of maceration, containing 30 and 70 ppm SO2. Changes of phenolic contents were observed during three stages of the wines: after maceration, after 6 and 16 months in order to check the effect of maceration time, SO2 and storage of the wines. Wines were stored at low and higher temperature to check also the influence of storage temperature on the studied parameters. It was found that maceration time influences the content of polyphenol compounds, observing increasing of their concentrations with increased maceration time, while lower contents were measured in the wines after 16 months of storage (3006, 1732 and 1602 mg/l total phenolics and 478, 188 and 98.5 mg/l total anthocyanins, after maceration, after 6 and 16 months of storage, respectively, in wine with 30 ppm SO2). SO2 had not a significant effect, whereas higher temperature caused slight changes of polyphenols contents

Effect of the Winemaking Practices and Aging on Phenolic Content of Smederevka and Chardonnay Wines

Changes of the polyphenolic content, including total phenolics (TP), total flavonoids (TF), and total flavan- 3-ols (TF3-ols) determined by spectrophotometric methods, have been studied in Macedonian white wines from Vitis vinifera L. cv, Smederevka and Chardonnay, obtained under different vinifications and analyzed during 16 months of aging in bottles. Winemaking treatments for both varieties included an addition of two doses of SO2 (50 and 100 mg/L) and two commercial yeasts for fermentation, Vinalco and Levuline, both Saccharomyces cerevisiae species, in order to study the influence of SO2 and yeasts on the phenolic content of the wines. Comparing the two varieties, Chardonnay wines contained higher levels of total phenolics, flavonoids, and flavan-3-ols, probably as a result of the cultivar differences. Sulfur dioxide protected the phenolic oxidation, resulting in higher phenolic content in the wines with higher SO2 dose, while the yeast did not show significant influence on the total phenolics. During aging, the TP, TF, and TF3-ols in the wines from both varieties decreased significantly up to the second month of storage and remained stable till the sixth month. The Student–Newman–Keuls test has been applied to ascertain possible significant differences between the studied wines, and a principal component analysis has been employed, showing separation and grouping of the wines according to the cultivar and time of aging

Effect of the Winemaking Practices and Aging on Phenolic Content of Smederevka and Chardonnay Wines

Changes of the polyphenolic content, including total phenolics (TP), total flavonoids (TF), and total flavan- 3-ols (TF3-ols) determined by spectrophotometric methods, have been studied in Macedonian white wines from Vitis vinifera L. cv, Smederevka and Chardonnay, obtained under different vinifications and analyzed during 16 months of aging in bottles. Winemaking treatments for both varieties included an addition of two doses of SO2 (50 and 100 mg/L) and two commercial yeasts for fermentation, Vinalco and Levuline, both Saccharomyces cerevisiae species, in order to study the influence of SO2 and yeasts on the phenolic content of the wines. Comparing the two varieties, Chardonnay wines contained higher levels of total phenolics, flavonoids, and flavan-3-ols, probably as a result of the cultivar differences. Sulfur dioxide protected the phenolic oxidation, resulting in higher phenolic content in the wines with higher SO2 dose, while the yeast did not show significant influence on the total phenolics. During aging, the TP, TF, and TF3-ols in the wines from both varieties decreased significantly up to the second month of storage and remained stable till the sixth month. The Student–Newman–Keuls test has been applied to ascertain possible significant differences between the studied wines, and a principal component analysis has been employed, showing separation and grouping of the wines according to the cultivar and time of aging

Nutritional phenolic compounds in red wines determined by HPLC-DAD-ESI-MS and MS/MS technique

Red wine is a rich source of bioactive and nutritional phenolic compounds which show antioxidant properties, present potential health effect, exhibit a free radical scavenging activity as well as a protective activity against arteriosclerosis, coronary heart disease or inhibit the cancer cell growth. In this study, the detailed phenolic profile of Macedonian red wines Vranec, Merlot and Cabernet Sauvignon, was determined. For that purpose, a high-performance liquid chromatography coupled with diode array detector and on line electrospray ionization mass spectrometry (HPLC-DAD-ESI-MS and MS/MS) was used for determination of the individual nutritional phenolic compounds in the wines. For analysis of anthocyanins and other pigments, wines were only diluted with 0.1M HCl (1:4). A solid-phase extraction with Oasis MCX cartridges was applied for separation of flavonols, phenolic acids and stilbenes [1,2]. ESI-MSn analysis were performed in positive ionization mode for identification of anthocyanins, flavonols and flavan-3-ols, and for gallic acid, hydroxycinnamic acid derivatives and stilbenes determination, ESI operated in negative ionization mode [3]. Complex phenolic profile was revealed for all wines composed of anthocyanins, vitisins, hydroxyphenyl-pyranoanthocyanins, flavonols, hydroxycinnamic acid derivatives, flavan-3-ols and stilbenes. Vranec wine was richest in all phenolics, especially anthocyanins that make it deeply colored, fresh and stable, appropriate for production of high quality red wines [4]

Comparison of four merlot clonal selections from Skopje's vineyard region, R.Macedonia

Merlot clonal selections located in Skopje's vineyard region, R.Macedonia, were studied during the period from 2005 to 2007. The aim was making a comparative examination of some agrobiological and technological characteristics of four Merlot clonal selections (181, 184, 346 u 348), cultivated in same agrotechnical and ampelotechnical measures. Different values for the examined characteristics were gained as a result of the grape variety specifications and ecological conditions during the examination years. During the examination period, Merlot clonal selection 181 has the most stabile yields with varying coefficient of 17,58 and the Merlot clonal selection 348 has the most biggest varying coefficient of 32,8. In the chemical composition of must some significant variations in the compositions of all acids, and insignificant variations in the sugar-glucose are noticed. The total average tasting value of 17.6 points was smallest at the wine produced from clone 184 and biggest at wines produced from clones 181 and 348 with 17.9 points

Characterization of Merlot wines based on phenolic composition determined by HPLC-DAD-ESI-MS and MS/MS technique

The concentration of phenolic compounds in wine depends on many factors, such as the variety, climate, soil, oenological practices applied for winemaking, aging and storage conditions. The purpose of this investigation was to determine the detailed phenolic profile of Merlot wines (vintage 2008), produced in Tikveš wine region in Republic of N. Macedonia. High-performance liquid chromatography with diode array detection coupled to mass spectrometry (HPLC-DAD-ESI-MS/MS) was used to identify and quantify the phenolic compounds in wines. Identification of the individual phenolic compounds was carried out by comparison of their UV/Vis spectra and retention times with those of the available standards, as well as by comparing the ESI-MS and MS/MS data with the standards analyzed under the same experimental conditions and those found in the literature. Different families of phenolic compounds were considered: anthocyanins, vitisins, hydroxyphenyl-pyranoanthocyanins, flavonols, hydroxycinnamic acids derivatives and stilbenes. With regards to pigments, malvidin-3-glucoside and its 3-acetylglucoside and 3-p-coumaroylglucoside derivatives were the major anthocyanins, while vitisin A and 10-DHP-pyranomalvidin-3-glucoside (pinotin A) were the dominant pyranoanthocyanins. Obtained results are significant data for the Macedonian winemaking industry to understand the nature and content of phenolic compounds in Merlot wines, as the most important components that influence the color, stability and sensorial properties of wines

HPLC analysis of hydroxycinnamic acid derivatives in Smederevka and Chardonnay wines

A reversed phase liquid chromatographic method for identification and quantification of hydroxycinnamic acid derivatives was used to analyze their content in Macedonian white wines, Smederevka and Chardonnay (Vitis vinifera L.) produced under different vinifications. Winemaking procedures for both varieties included addition of two doses of SO2 (50 and 100 mg/L) and two yeasts for fermentation (Vinalco and Levuline). Separation of the components by direct injection into HPLC was performed using reversed-phase Atlantis dC18 column, monitored at 320 nm, and the mobile phase consisted of water/formic acid (99:1; solvent A), and acetonitrile/water/formic acid (80:19:1; solvent B). The main phenolic acids present in the wines were caftaric acid (caffeoyltartaric acid) and coutaric acid (coumaroyltartaric acid). In addition, HPLC-MS analysis was carried out to confirm the identity of the separated compounds, recording the spectra in negative ion mode. In general, differences in their contents in Smederevka and Chardonnay wines were observed. Thus, Chardonnay wines were richer in phenolic acids compared to Smederevka wines. The dominant component in Chardonnay wines was trans-caftaric acid, while, trans-coutaric dominated in Smederevka wines. Regarding the influence of SO2, it was observed that wines with higher dose of SO2 contained higher levels of acids, since SO2 suppress the activity of oxidases, preventing oxidation of these readily oxidizable phenols and wine browning. The influence of the yeast on the content of phenolic acid derivatives was not significant. Principal component analysis was performed in order to check if the studied wines can be distinguished, showing separation of the samples according to the variety and SO2 doses