Polyphenols present in red table grape varieties Red Globe, Flame Seedless, Crimson and Napoleon, the white Superior Dominga, Moscatel Italica were analyzed by HPLC−DAD−MS. The anthocyanins peonidin 3-glucoside, cyanidin 3-glucoside (and their corresponding p-coumaroyl derivatives), malvidin petunidin delphinidin found. In addition, caffeoyltartaric acid, p-coumaroyltartaric flavonols quercetin 3-glucuronide, 3-rutinoside, kaempferol 3-galactoside, isorhamnetin detected. Flavan-3-ols also...

The effect of minimal processing on polyphenol oxidase (PPO), peroxidase (POD), phenylalanine ammonia-lyase (PAL), and phenolic compounds was studied in five potato cultivars (Agria, Cara, Liseta, Monalisa, Spunta). Minimal caused an overall increase PPO, POD, PAL activities. isoform pattern PPO the same for all before after processing. No latent detected. isoperoxidase approximately among cultivars. An POD activity related to specific induction acidic isoperoxidase. showed characterized by...

In the skin of cv. Napoleon table grapes, anthocyanins malvidin 3-glucoside (and its acetyl and p-coumaroyl derivatives), cyanidin 3-glucoside, peonidin petunidin delphinidin were identified by HPLC-DAD-MS. addition, quercetin 3-glucuronide, caffeoyltartaric, piceid, resveratrol also detected. The content most phenolics remained quite constant during postharvest refrigerated storage (10 days at 0 degrees C) while derivatives increased 2-fold. Postharvest treatments grapes with UVC UVB light...

The aim of the present work was to identify and quantify phenolic compounds fatty acids in acorns from Quercus ilex, rotundifolia, suber. concentration oleic acid >63% total all cases, followed by palmitic linoleic at similar concentrations (12−20%). α-tocopherol Q. suber were 19, 31, 38 mg/kg dry matter (DM), respectively, whereas γ-tocopherol 113, 66, 74 DM, respectively. Thirty-two different distinguished. All them gallic derivatives, form either galloyl esters glucose, combinations...

The use of postharvest controlled irradiation by UV pulses is proposed as a potential method to produce stilbene-enriched red wine. "Monastrell" grapes were UV-C-irradiated increase stilbene content. main inducible stilbenes resveratrol and piceatannol, which are molecules with reported health-beneficial activities. evolution both compounds was followed in the different steps an "analytical" traditional maceration wine-making process. final wine made from enriched about 2- 1.5-fold...

A modeling method for the induction of resveratrol synthesis by UV irradiation pulses in Napoleon table grapes is proposed. The based on combination four main parameters: power (IW), time (IT), distance (ID), and number elapsed days to achieve highest accumulation (Dm). Maximum content (11-fold higher than untreated grapes) was achieved using combination: IW = 510 W, IT 30 s, ID 40 cm, Dm 3 days. Sensory characteristics features irradiated (color, weight, firmness, flavor, size, ripening...

Hydroxytyrosol (HTyr), a natural ortho-diphenolic antioxidant with health-beneficial properties that mainly occurs in virgin olive oil and mill waste waters (also known as vegetative waters), has been enzymatically synthesized using mushroom tyrosinase. This o-diphenol (not commercially available) was obtained from its monophenolic precursor tyrosol (commercially the presence of both tyrosinase ascorbic acid. The reaction synthesis is continuous, easy to perform, adaptable bioreactor for...

The effect of fresh-cutting and subsequent cold storage on phenolic compounds from five long-term-stored potato cultivars (Agria, Cara, Liseta, Monalisa, Spunta) was studied. Fresh-cutting induced the biosynthesis three flavonols, which were identified by HPLC-DAD-ESIMS as quercetin 3-rutinoside, 3-diglucoside, 3-glucosylrutinoside. flavonols detected after a lag period 3 days storage. content ranged 6 to 14 mg/100 g fresh weight depending cultivar Chlorogenic acid main caffeic derivative...

The red table grape varieties Flame, Red Globe, Crimson, and Napoleon, as well the white Superior, Dominga, Moscatel Italica, were irradiated with a previously optimized UV-C postharvest irradiation protocol (510 W, 40 cm, 60 s). induction kinetics of stilbenes trans-resveratrol, trans-piceid, trans-piceatannol, trans-astringin, viniferins was followed by using HPLC-DAD/MS/MS. most inducible viniferins. Both quantitative qualitative differences observed in both stilbene content seven grapes...

Postharvest treatment of seedless white table grapes (var. 'Superior') with different gas ozone concentrations (3.88 and 1.67 g/h) for 1, 3, 5 h induced an increase in stilbenoid biosynthesis [trans-resveratrol, piceatannol, viniferinas (resveratrol dehydrodimers dehydrotrimers)] during storage at 22 degrees C 95% relative humidity. The maximal resveratrol concentration was reached after 2 days storage, this amount similar to that by optimized UV-C treatments (1 min, 510 W, 40 cm). Although...

Abstract: Melatonin is a bioactive compound that present in wine because it contained vinification grapes and synthesized by yeast during alcoholic fermentation. The purpose of this study was to determine the capacity various Saccharomyces strains form melatonin its growth A selection yeasts including six S. cerevisiae (Lalvin CLOS, Lalvin ICV‐D254, Enoferm QA23 Viniferm ARM, RVA, TTA), one uvarum S6U) var. bayanus (Uvaferm BC) were tested whether they produce extract peptose dextrose...

Stilbene-enriched extracts from Vitis vinifera waste (cane, wood, and root) were characterized by UHPLC-MS. Eleven stilbenes identified quantified as follows: ampelopsin A, (E)-piceatannol, pallidol, (E)-resveratrol, hopeaphenol, isohopeaphenol, (E)-ε-viniferin, (E)-miyabenol C, (E)-ω-viniferin, r2-viniferin, r-viniferin. The fungicide concentration inhibiting 50% of growth Plasmopara viticola sporulation (IC50) was determined for the also main compounds isolated. r-Viniferin followed...