Search results for "anthocyanins"
showing 10 items of 75 documents
Increase of trans-resveratrol in typical Sicilian wine using β-Glucosidase from various sources
2008
β-Glucosidase (EC 3.2.1.21) (β-G) from different sources were tested to increase the trans-resveratrol in some Sicilian wines by hydrolysing resveratrol glucoside. β-G from Aspergillus niger mould was tested as a crude and purified enzyme, and compared with the same enzyme from Saccharomyces cerevisiae yeast. Specific purification served to eliminate collateral enzyme activities so that β-G could be used simply and economically. Aspergillus niger β-G produced trans-resveratrol increases of up to 75%, with no change in physico-chemical properties and bouquet, and an increase in health and nutritional properties. S. cerevisiae β-G raised free-terpenol levels, but impaired wine colour due to a…
Evolution of anthocyanin profile from grape to wine
2010
<p style="text-align: justify;"><strong>Aims</strong>: This study aimed at acquiring knowledge of the evolution of anthocyanins from grape to wine and the possibility of deducing the varietal origin of a wine from its anthocyanin profile.</p><p style="text-align: justify;"><strong>Methods and results</strong>: The anthocyanin « fingerprint », or profile, of a series of autochthonous Sicilian accessions and their respective young wines was determined by HPLC-DAD in 2008. Data were evaluated by taking into account the evolution of the percentages of side-ring dioxygenated and tri-oxygenated anthocyanins, the ratio between acetylated and p-coumaroylate…
Green and Quick Extraction of Stable Biophenol-Rich Red Extracts from Grape Processing Waste
2021
The extraction of grape processing waste (wine pomace) via microwave-hydrodiffusion and gravity (MHG) from three different cultivars grown in Sicily (Syrah, Perricone and Nero d&rsquo;Avola) rapidly affords aqueous extracts highly concentrated in valued biophenols including flavonoids, anthocyanins and phenolic acids. The method does not employ organic solvent, acid or base and does not require grinding or freeze drying of the wine pomace nor separation of the grape skins from seeds and stem. All the extracts have a pronounced stability as shown by their red-violet color fully retained after storage for more than a year (15 months) in freezer under air. Concentrations of phenolics up to…
EVOLUTION OF ANTHOCYANIN PROFILES FROM GRAPE TO WINE
2010
Aims: This study aimed at acquiring knowledge on the evolution of anthocyanins from grape to wine and the possibility of deducing the varietal origin of a wine from its anthocyanin profile. Methods and results: The anthocyanin “fingerprints”, or profiles, of a series of autochthonous Sicilian accessions and in the respective young wines were determined by HPLC-DAD in 2008. Data were evaluated by taking into account the development of percentages of side-ring disubstituted and trisubstituted anthocyanins, the ratio between acetylated and p-coumaroylated derivatives, and PCA results. From grape until the end of alcoholic fermentation, percentages of 3-glucosides of cyanidin, peonidin, delphin…
Behaviour of some compounds with lmax at 280 nm in determination of total flavonoids of grape skin extracts made from a hydroalcoholic SO2-rich solve…
2010
This paper reports the results of a study on the ambiguous behaviour of substances with lmax at 280 nm in the determination of total flavonoids in whole grape skin extracts made from a hydroalcoholic SO2-rich solvent, apparently not eluted with methanol after absorption on a C18 cartridge employed for sample pre-concentration and SO2 removal. After rejecting the hypothesis that they were irreversibly absorbed on the C18 cartridge, it seemed that they reacted with other phenolics during passage through the C18 cartridge and were totally eluted with methanol in this new combined form. This new hypothesis seems very probable and is in accord with the more recent acquisition about the synthesis…
Effect of different processing methods on the quality of obtained pomegranate juice
2019
Pomegranate juice has many health properties as the fruits contain anticarcinogenic, antimicrobial and antiviral compounds. Its consumption has greatly increased throughout the world in recent years due to the potential of its different components, polyphenols and anthocyanins mostly. Many studies have been performed on the pomegranate juice yield demonstrating its influence on the organoleptic and physicochemical properties of the juice. Commercial pomegranate juice production involves pressing the fruits. As a consequence, there is a need to investigate the pressing machine types and adjustment in order to maximize juice yield and enhance its health properties. The aim of this study was t…
A SELECTIVE EXTRACTION OF ANTHOCYANINS FROM EGGPLANT PEEL
2007
Enzyme-assisted extraction of anthocyanins and other phenolic compounds from blackcurrant (Ribes nigrum L.) press cake: From processing to bioactivit…
2022
The effects of commercial enzymes (pectinases, cellulases, beta-1-3-glucanases, and pectin lyases) on the recovery of anthocyanins and polyphenols from blackcurrant press cake were studied considering two solid:solvent ratios (1:10 and 1:4 w/v). β-glucanase enabled the recovery of the highest total phenolic content – 1142 mg/100 g, and the extraction of anthocyanins was similar using all enzymes (∼400 mg/100 g). The use of cellulases and pectinases enhanced the extraction of antioxidants (DPPH − 1080 mg/100 g; CUPRAC – 3697 mg/100 g). The freeze-dried extracts presented antioxidant potential (CUPRAC, DPPH), which was associated with their biological effects in different systems: antiviral a…
Effect of grafting on yield and quality of eggplant (Solanum melongena L.)
2013
Eggplants have fruits with different sizes, shapes and colours, according to the cultivar. Skin colour is due to anthocyanins, pigments located in the cell vacuole of fruit skin that belong to phenolic flavonoids, a powerful antioxidants group. Environmental conditions and growing techniques may influence fruits characteristics and their content of phenolic compounds. Grafting is a non chemical alternative for overcoming the effects of intensive and continuous cropping. The rootstocks preferred for eggplant are hybrids of tomato or tomato KVFN. Also species taxonomically close, as Solanum torvum, have been used and showed good vigour, compatibility and resistance to wilt disease. Informatio…
Flavonoid metabolism and gene expression in developing olive (Olea europaea L.) fruit.
2012
The expression pattern of six genes (phenylalanine-ammonia-lyase, PAL, chalcone synthase, CHS, flavanone 3-hydroxylase, F3H, dihydroflavonol 4-reductase, DFR, anthocyanidin synthase, ANS, UDP-gluco...