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Plovdiv, Bulgaria

Yaneva V.,AMB AGRO | Babrikov D.,Mendeleev University of Chemical Technology | Mashev N.,Mendeleev University of Chemical Technology
Oxidation Communications | Year: 2010

Grape berries, skins and semi-seeds of three seedless table varieties - Hibrid-10, Blyan and Russalka-3 and the seeds of two seeded grape varieties - Muscat Hambourg and Bolgar, have been evaluated for their polyphenol profile and antioxidant activity. The contents of the various phenol fractions varied from 6127 to 27 550 mg/kg for total phenols (TP), from 213 to 6000 mg/kg for nonflavonoid phenols (NFP), from 402 to 21 550 mg/kg for flavonoid phenols (FP) and from 188 to 8375 mg/kg for total flavanols (F-3-ols, procyanidins). The antioxidant activity determined by three assay methods (DPPH, FRAP and ABTS) varied in wide ranges in the grape berries, skins, semi-seeds and seeds. The empty and soft seeds of the seedless varieties have higher content of polyphenols in their dry matter, and their DPPH, FRAP and ABTS activity is by 20-25% superior to that of the seeds of Muscat Hambourg and Bolgar varieties. Among the coloured grape varieties studied, the seedless and coloured grape variety Hibrid-10 is distinguished by its highest polyphenols content and highest antioxidant activity and among the non-coloured ones - the seedless variety Blyan. The comparison of the results obtained with that of other authors disclosed that these grape by-products can be regarded as a new source of nutritive polyphenols possessing antioxidant action and revealed the advantages and healthy effects of the seedless table varieties in comparison with the seeded ones. Source

Braikov D.,Mendeleev University of Chemical Technology | Masheva L.,Mendeleev University of Chemical Technology | Yaneva V.,AMB AGRO
Oxidation Communications | Year: 2011

The effect of exogenous application of some phytohormones such as indol-3-acetic acid (IAA), gibberrellic acid (GA3) and kinetin (6-furforylaminopurpurine) as components of CP and ethylene-releasing Ethrel preparations on the chemical composition of Mavrud grape shoots has been investigated. The contents of total sugars, saccharose and reducing sugars, starch and cellulose, in the ripe shoots were determined at the end of November. The various nitrogen species, i. e. total protein, peptide, amino acid and ammonium nitrogen, as well as total protein amino acids in the grape shoots have been quantified. The results show that the treatment with CP induces an increase in the content of some carbohydrates and nitrogen fractions - about 50%, in others - by 10-20%, and some do not change. It was established that protein, peptide and amide nitrogen of the nitrogen ingredients, and glucose, fructose and starch of the carbohydrates manifest major reserve cryoprotecting properties under the action of phytohormones in grape shoots. The amount of some protein amino acids changes from 10 to 50% depending on the treatment with KP, KP and Ethrel. The treatment with KP induces a 39% increase in the content of hydroxyl amino acids, 29% of the basic and 27% of sulphur-containing acids in the grape shoots proteins of the CPtreated variant. The obtained results are discussed in a view of improving the cold stress resistance of Mavrud grape variety. Source

Yaneva V.,AMB AGRO | Yaneva V.,Mendeleev University of Chemical Technology | Braikov D.,AMB AGRO | Braikov D.,Mendeleev University of Chemical Technology | And 2 more authors.
Oxidation Communications | Year: 2010

The treatment of the Mavrud grape cultivar - an economically important Bulgarian wine variety - with the Atonik preparation (a mixture of Na nitrophenolates) positively affects the grape yield and quality. The treatment causes an increase in the content of total phenols (TP), nonflavonoid (NFP) and flavonoid phenols (FP) as well as of total flavanols (F-3-ols) in the grape berries, skins and seeds. The antiradical activity of grape berries, skins and seeds at treatment with Atonik, CITRO-K and CA-20 varies in wide ranges - from 1.79 to 39.40 μmol DPPH/g fresh mass. The strongest effect is observed at the treatment with 0.08-0.1 1 da -1 Atonik and 0.3 1 da -1 CITRO-K in the grape skins, which is 9.84 and 10.33 μmol DPPH/g fresh mass, respectively (28% with respect to the control sample). The highest ferric reducing antioxidant power is displayed at treatment with 0.1 1 da -1 Atonik of the skins and for the berries - at treatment with 0.3 1 da -1 CA-20 (40% with respect to the control). Among the three preparations the strongest effect is exerted by the Atonik preparation in concentrations of 0.08 and 0.1 1 da -1, which observation offers possibility for its utilisation to increase the polyphenol content composition and improve the enological and nutritive properties of the Mavrud grape cultivar. Source

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