Identification of polyphenolic compounds in red and white grape varieties grown in R. Macedonia and changes of their content during ripening

Abstract

The composition of polyphenols in the skin, seed and pulp extracts of the grapes of Vranec and Smederevka varieties, and Merlot and Chardonnay as well, was analyzed by liquid chromatography-diode array detectionmass spectrometry (HPLC-DAD-MS) and MS/MS techniques. Thirty-one phenolic compounds, including anthocyanins, flavonols and flavan-3-ols, as well as phenolic acids derivatives, have been identified in the extracts prepared from the grapes at physiological maturity, by mass spectrometry applying electrospray ionization operated in alternating ion mode and by performing tandem MS experiments in the ion trap mass analyzer. Grapes were analyzed at three different phases: (i) veraison, (ii) physiological ripeness and (iii) late harvest, in order to follow the evolution of polyphenolic content during berry development, applying spectrophotometric methods. Vranec had a higher polyphenolic content compared to Merlot due to the higher levels of total phenolics and flavonoids in the skins and seeds as well as a higher content of flavan-3-ols and anthocyanins in the skins, allowing discriminating the varieties. HPLC-DAD-MS analysis presented significantly higher relative amounts of anthocyanin monoglucosides and p-coumaroylglucosides in Vranec grapes. Smederevka seeds had a higher amount of flavan-3-ols than Chardonnay, while a higher content of total phenolics and flavonoids was found in the skins of the Chardonnay variety. Anthocyanin content in both red varieties increased during the berry ripening, while flavan-3-ols in seeds were mainly accumulated in the veraison phase followed by decrease of the content with ripening.Crown

Effects of Cultural Practices on Total Phenolics and Vitamin C Content of Organic Table Grapes

“…One interesting result was that 'Red Globe' had less total phenolic compounds than 'Buca Razakısı' in all the treatments, except for the girdling alone. This is a result that conflicts with previous studies, which have reported that white varieties generally have fewer phenolic compounds than coloured varieties (Cantos et al, 2002;Lachman et al, 2004;Ivanova et al, 2011). This might have been the result of the 'Red Globe' vines being harvested before they had the chance to reach their "phenological maturity".…”

“…The coloured varieties, 'Alphonse L.', 'Red Globe' and 'Trakya Ilkeren', contained more phenolics in their berries, as expected, compared to 'Buca Razakısı', the white cultivar. Coloured grape cultivars accumulate more anthocyanins in the skin and has the highest total polyphenols (Ivanova et al, 2011). One interesting result was that 'Red Globe' had less total phenolic compounds than 'Buca Razakısı' in all the treatments, except for the girdling alone.…”

Differentiation of wines with the use of combined data of UV–visible spectra and color characteristics

“…The formation of color in grapes generally takes place during the veraison period with the biosynthesis of phenolic compounds (Ivanova et al, 2011;Kalkan Yildirim, 2006). In wine, color develops by the extraction of phenolic compounds in the grape during crushing, maceration and fermentation, and evolves through oxidation and aging (Gó mez-Míguez et al, 2007;Ivanova et al, 2011).…”

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

“…As expected, no anthocyanins were determined in the flours obtained from 'Italian Riesling', because white cultivars lack the UFGT expression, a gene involved in anthocyanins synthesis (Boss et al, 1996). Also, as support to these results, other studies reported the lack of anthocyanins in white grapes (Kammerer et al, 2004;Ivanova et al, 2011). On the other hand, this analytical was 535 performed by taking into account the early discovery of the occurrence of anthocyanins in white berries of Muscat Gordo Blanco cultivar (Gholami and Coombe, 1995).…”