Anthocyanins are major pigments in colored grape (Vitis vinifera) berries, and most of them are monomethoxylated or dimethoxylated. We report here the functional characterization of an anthocyanin O-methyltransferase (AOMT) from grapevine. The expression pattern in two cultivars with different anthocyanin methylation profiles (Syrah and Nebbiolo) showed a peak at start ripening (véraison), when...

Frozen blueberries (Vaccinium corymbosum L.) were processed into juice and concentrate, and the changes in anthocyanin pigments and polyphenolics (cinnamates, procyanidins, flavonol glycosides) were monitored. While juice yield was 83%, only 32% of the anthocyanins were recovered in single-strength juice. Flavonol, procyanidin and chlorogenic acid recoveries in juice were 35%, 43%, and 53%, res...

Plants of Malva sylvestris L. were studied for change in growth pattern and their anthocyanin production, malvidin and delphinidin with abscisic acid (ABA) treatment. Exogenous administration of ABA as foliar spray for five successive days significantly increased anthocyanin content up to five fold with induced morphological variations by increasing height, leaf mass, leaf number, fresh and dry...

Potatoes regarding their consumption are a significant antioxidant source in human nutrition. The main potato antioxidants are polyphenols, ascorbic acid, carotenoids, tocopherols, α-lipoic acid, and selenium. The most contained polyphenolic antioxidants in potatoes are L-tyrosine, caffeic acid, scopolin, chlorogenic and cryptochlorogenic acid and ferulic acid. In red and purple potatoes are in...

Callus cultures were established in vitro from leaf explants of Malva neglecta and were sub-cultured several times until a rapid-growing cell line was obtained. The calluses were exposed to different doses of ultraviolet (UV) radiation as follows: 0, 432, 864, and 1296 J/m2 for UV B and 0, 612, 1284, and 1836 J/m2 for UV C, corresponding to 0, 30, 60, and 90 min radiations, in tandem. Exposure ...

This research evaluated blackberries grown in Oklahoma and wines produced using a modified traditional Korean technique employing relatively oxygen-permeable earthenware fermentation vessels. The fermentation variables were temperature (21.6°C versus 26.6°C) and yeast inoculation versus wild fermentation. Wild fermented wines had higher total phenolic concentration than yeast fermented wines. O...

In the present research, the copigmentations of malvidin-3-O-glucoside with five hydroxybenzoic cofactors (p-hydroxybenzoic acid, protocatechuic acid, gallic acid, vanillic acid, and syringic acid) were investigated. The influence of the concentration of these cofactors and the reaction temperature was examined. The equilibrium constant (K), stoichiometric ratio (n) and the thermodynamic parame...

Anthocyanins are naturally occurring polyphenols that impart bright color to fruits, vegetables and plants. In this study, the extraction of anthocyanins from freeze-dried fruit skin of downy rose-myrtle (Rhodomyrtus tomentosa (Ait.) Hassk var. Gangren) was optimized using response surface methodology (RSM). Using 60% ethanol containing 0.1% (v/v) hydrochloric acid as extraction solvent, the op...

By-products obtained from winemaking processes still contain large amounts of phenolic compounds, especially phenolic acids, flavanols, flavonols, stilbenes, and flavonoids. Enzymatic hydrolysis was used for determination and characterization of phenolic acids, flavanols, flavonols, and stilbenes. Characterization of the flavonoids was achieved using acid hydrolysis with 0.1% hydrochloric acid....