Evaluating the Polyphenol Profile in Three Segregating Grape (Vitis vinifera L.) Populations

This paper explores the characteristics of the anthocyanin and flavonol composition and content in grapes from plants resulting from intraspecific crosses of Vitis vinifera varieties Monastrell × Cabernet Sauvignon, Monastrell × Syrah, and Monastrell × Barbera, in order to acquire information for future breeding programs. The anthocyanin and flavonol compositions of twenty-seven hybrids bearing red grapes and 15 hybrids bearing white grapes from Monastrell × Syrah, 32 red and 6 white from Monastrell × Cabernet Sauvignon, and 13 red from Monastrell × Barbera have been studied. Among the intraspecific crosses, plants with grapes presenting very high concentrations of anthocyanins and flavonols were found, indicating a transgressive segregation for this character, and this could lead to highly colored wines with an increased benefits for human health. As regards the qualitative composition of anthocyanins and flavonols, the hydroxylation pattern of the hybrids that also may influence wine color hue and stability presented intermediate values to those of the parentals, indicating that values higher than that showed by the best parental in this respect will be difficult to obtain. The results presented here can be helpful to acquire information for future breeding efforts, aimed at improving fruit quality through the effects of flavonoids. 1. Introduction Anthocyanins are responsible for the color of red grape varieties and the wines produced from them. Flavonols are also important because they participate both in stabilizing anthocyanins in young red wines through copigmentation and in increasing the health-related properties of wine [1, 2]. Grape anthocyanins and flavonols are final products arising from the flavonoid biosynthetic pathway (Figure 1). Vitis vinifera varieties are characterized by the presence of 3-O-glucosides of delphinidin, peonidin, petunidin, cyanidin, and malvidin, together with their acylated derivatives [3]. The 3-O-glucosides of kaempferol, quercetin, and myricetin are the major flavonols in grapes as first reported by Cheynier and Rigaud [4] and recently confirmed by Castillo-Mu？oz et al. [5], with quercetin glycosides usually being dominant [5], although a high presence of quercetin-3-O-glucuronide has also been observed in some varieties such as Petit Verdot [5, 6]. Figure 1: Flavonoid biosynthetic pathway. PAL: phenyl ammonia lyase, F3′H: flavonoid-3′-hydroxylase, F3′5′H: flavonoid-3′,5′-hydroxylase, UFGT: UDP-glucose: flavonoid 3-O-glucosyltransferase, MT: methyl transferase, DFR: dihydroxyflavanol-4-reductase, ANS: anthocyanin