Comparative Polyphenolic Content of Grape Pomace Flours from ‘Fetească neagră’ and ‘Italian Riesling’ Cultivars

Grape pomace is a waste from wine industry which pollutes the environment. This by-product is considered a potential source of polyphenols, which were proven to be powerful antioxidants or natural coloring agents. The aim of this study was to quantify total polyphenols, total anthocyanins content and some stilbenes in grape pomace seed, skin and mixed flours from ‘Fetească neagră’ (cultivar for red wines) and ‘Italian Riesling’ (cultivar for white wines), grown in Miniș-Măderat vineyard, Romania. Flours were obtained by natural drying and ulterior grinding. One-way ANOVA and Tukey’s post-hoc test were used.anthocyanins content was high in all the flours from ‘Fetească neagră’, with the highest concentration in skin flour (35.98 mg malvidin-3-O-glucoside/g dry weight). Stilbenes were also determined through HPLC methods. Cis-resveratrol was present in all forms of flour (0.90 to 10.14 μg/g dry weight), compared to its trans-isomer, which was not determined in ‘Italian Riesling’ seed and mixed flour. Trans-piceid was the most abundant stilbene and varied between 12.35 μg/g dry weight (‘Italian Riesling’ mixed flour) and 29.01 μg/g dry weight (‘Fetească neagră’ seed flour). The concentration of cis-piceid was similar among all forms of flour from ‘Italian Riesling’, while in ‘Fetească neagră’ seed flour (9.40 μg/g dry weight) it was present at a higher rate. Thus, results proved that ‘Fetească neagră’ flours are a better source of stilbenes than ‘Italian Riesling’ flours and seed flours from both varieties are richer in polyphenols than skin flours. Also, the concentration of anthocyanins in ‘Fetească neagră’ skin flour was high

Qualitative Assessment of the White Wine Varieties Grown in Dealu Bujorului Vineyard, Romania

Ecoclimatic conditions have a great influence on grapevine growth and development. Favourable conditions (solar radiation, temperature, humidity etc.) are important and have a positive effect on the growth and fruition. Critical conditions have negative influences resulting in low grape production and wine quality. The purpose of this research was to analyse the quality of wine obtained from eight grapevine varieties (four Romanian autochthonous varieties: ‘Feteasca regala’, ‘Feteasca alba’, ‘Babeasca gri’, ‘Sarba’, and four world-wide varieties: ‘Aligoté’, ‘Sauvignon Blanc’, ‘Muscat Ottonel’, and ‘Italian Riesling’). The wine samples were obtained from micro-wine production under local weather conditions of Dealu Bujoruluivineyard, Romania. The physico-chemical analysis of young wines showed that the highest alcohol content was recorded at the ‘Sauvignon blanc’ variety (14.35% vol.) followed by ‘Sarba’ (14.10% vol.). The highest level of acidity was registered to ‘Babeasca gri’ (5.90 g/L C4H6O6) and the lowest acidity in the ‘Muscat Ottonel’ wine (4.40 g/L C4H6O6). The pH values were between limits of 3.62 (‘Feteasca alba’) and 3.27 (‘Aligote’). In order to get a wider perspective about the wine quality, another 11 parameters were examined at these varieties, using spectrophotometric methods (acetic acid, potassium, calcium, free amino nitrogen, tartaric acid, copper, L-lactic acid, iron, L-malic acid, D-gluconic acid and glycerol). The results showed the suitability of ecoclimatic conditions and the proper growth and development of the tested varieties for obtaining wines withsuperiors quality

Comparative Polyphenolic Content of Grape Pomace Flours from ‘Fetească neagră’ and ‘Italian Riesling’ Cultivars

Grape pomace is a waste from wine industry which pollutes the environment. This by-product is considered a potential source of polyphenols, which were proven to be powerful antioxidants or natural coloring agents. The aim of this study was to quantify total polyphenols, total anthocyanins content and some stilbenes in grape pomace seed, skin and mixed flours from ‘Fetească neagră’ (cultivar for red wines) and ‘Italian Riesling’ (cultivar for white wines), grown in Miniș-Măderat vineyard, Romania. Flours were obtained by natural drying and ulterior grinding. One-way ANOVA and Tukey’s post-hoc test were used.anthocyanins content was high in all the flours from ‘Fetească neagră’, with the highest concentration in skin flour (35.98 mg malvidin-3-O-glucoside/g dry weight). Stilbenes were also determined through HPLC methods. Cis-resveratrol was present in all forms of flour (0.90 to 10.14 μg/g dry weight), compared to its trans-isomer, which was not determined in ‘Italian Riesling’ seed and mixed flour. Trans-piceid was the most abundant stilbene and varied between 12.35 μg/g dry weight (‘Italian Riesling’ mixed flour) and 29.01 μg/g dry weight (‘Fetească neagră’ seed flour). The concentration of cis-piceid was similar among all forms of flour from ‘Italian Riesling’, while in ‘Fetească neagră’ seed flour (9.40 μg/g dry weight) it was present at a higher rate. Thus, results proved that ‘Fetească neagră’ flours are a better source of stilbenes than ‘Italian Riesling’ flours and seed flours from both varieties are richer in polyphenols than skin flours. Also, the concentration of anthocyanins in ‘Fetească neagră’ skin flour was high