A method was developed for the fractionation of grape and wine proanthocyanidins according to their degree of polymerization. The grape and wine proanthocyanidins were fractionated on C18 Sep-Pak cartridges into three fractions by different organic solvents. The combination of TLC, analytic HPLC, and degradation with toluene-R-thiol confirmed that these three fractions contained, respectively, ...

Two varieties of grapes, white grape and red grape grown in the Campania region of Italy were selected for the study of drying characteristics. Comparisons were made with treated and untreated grapes under constant drying condition of 50 C in a conventional drying system. This temperature was selected to represent farm drying conditions. Grapes were purchased from a local market from the same s...

Phenolic compound profiles were investigated by HPLC-MS in two consecutive years to assess genotypic variation in berry skins of nine red Vitis vinifera cultivars. The results showed that the types and levels of phenolic compounds greatly varied with cultivar. Common wine grape cultivars such as Syrah, Cabernet Sauvignon, Cabernet Gernischt and Merlot contained more types of anthocyanins, flavo...

The pomegranate (Punica granatum L.) is an important medicinal plant. It has been reported that phenolic compounds contained in the flowers have antioxidant potential. The objective was to determine the concentration of total phenolics and antioxidant capacity of three selections of pomegranate flower dried under different conditions. The highest phenolic content and antioxidant capacity was ob...

aceae), is one of the most widely prescribed and intensively studied herbal medicines. Ginsenosides, the secondary metabolites and unique constituents in the Panax plants, are the pharmacologically active ingredients of ginseng. There are two traditional preparations of ginseng, white ginseng (WG) and red ginseng (RG), the dried root of ginseng and the steamed/dried root of ginseng, respectivel...

The concentration of trans-resveratrol in 165 grape cane samples from three major grape production regions and four large distribution centers of Chinese wild Vitis species were determined by reversed-phase high-performance liquid chromatography (HPLC). Among the different genotype groups and purpose of uses, cultivars of V. vinifera had much higher amounts of trans-resveratrol than did the cul...

Polyphenols are a large and complex group of compounds responsible for the characteristics, quality, and color of grape and wine, especially for red ones. The polyphenolic composition has been extensively studied and a large family of structures have been identied in grapes and wine (Ribereau-Gayon 1965; Somers 1971; Nagel and Wulf 1979; Slinkard and Singleton 1984; Bourzeix et al. 1986; Cheyn...

Grape pomace is a potential source of natural antioxidant and antimicrobial agents. Phenolic compounds, antioxidant, and antibacterial properties of pomace extracts from four Virginia-grown grape varieties were investigated. White grape pomaces had higher (P < 0.05) solvent extraction yield than red varieties. Concentrations of total phenolic (TPC), total flavonoid (TFC), total anthocyanin (TAC...