Studii privind viabilitatea şi capacitatea de germinare a polenului unor soiuri Vitis vinifera L.

Pollen quality is an important indicator in the estimation of grape production, being analysed based on its germination capacity. Thus, viability and germination potential of pollen from six Vitisvinifera L. varieties, grownin the climatic area of the Iasi vineyard,were analysed. To perform the determinations, were used comparatively three methods for observingthe viable cells, by treating them with tetrazolium chloride (TTC), Lugol solution (IKI) and methylene blue (AM) solution. The germinating potential was analysed in vitro, the culture being performed on agar medium with added sucrose (0 to 20%). The viable cells weremore clearly highlighted using the AM method, but the TTC method was more accurate in indicating the percentage of pollen viability. The highest pollen germination rate was observed in the 15% added sucrose variant

Caracterizarea agrobiologică şi tehnologică a unor elite clonale pentru struguri de vin obţinute în cadrul S.C.D.V.V. Iaşi

Autochthonous and cosmopolitan grapevines varieties representa valuable source of germoplasm, which is particularly important for the breedingof the currently cultivated genotypes.Thestructural improvement of the national viticulturalassortment is supported by scientific research in the field of vine breeding, whose mission was and is to renew, diversify and increase the biological value of the vine assortment bycreating new qualitative and productive genotypes with superiorresistance todisease and stress factors, through both genetic engineering and clonal selection. The present paper contains the results obtained at the Research Development Stationfor Viticulture and Winemaking Iasi, referring to the agrobiological and technological characteristics of clonal elites selected from the populations of the varieties: Sauvignon blanc, Pinot gris and Cabernet Sauvignon. The clonal elites obtained, through the cultural and qualitative features for which they were selected, complementarily contribute to achievement of high quality grape productions

Studii privind extracţia compuşilor fenolici din coardele de viţă de vie

Étant donné que la taille de la vigne produit chaque année une grande quantité de déchets inutilisables, le but de cette étude était d'évaluer le potentiel des baguettes de vigne à être utilisées comme source naturelle de composés bioactifs pour les industries alimentaire, pharmaceutique et cosmétique. Afin d'optimiser les procédures d'extraction phénoliques, les baguettes de vigne de raisin de Cabernet Sauvignon ont été extraites avec diverses concentrations d'éthanol (0, 50, 70, 90 et 96%) et d'hydroxyde de sodium 1N, dans un rapport matière végétale/solvant de 1:10. Pour purification ultérieure sur des cartouches C18SPE préconditionnées, les surnageants ont été concentrés à sec dans un évaporateur rotatif sous vide. Après avoir déterminé la concentration optimale en solvant, le temps (<300 min) et la température (20, 40, 60 °C) nécessaires pour maximiser l'extraction des composés phénoliques ont été testés. La concentration la plus élevée en polyphénols a été obtenue lorsque l'extraction a été réalisée sur des baguettes de vigne broyées (particules <0,5 mm), avec une solution d'éthanol 70%, 4 heures à 60 °C. Après application de températures élevées, l'activité antioxydante et le pouvoir réducteur ferrique des extraits sont restés élevés(94,01% de DPPH nettoyé). Les résultats de la recherche indiquent que les baguettes de vigne sont sources durables de composés polyphénoliques avec fonction sanogène, actuellement inexploitées au potentiel technologique et économique réel

Studii privind corelaţia dintre activitatea polifenoloxidazei şi conţinutul fenolic total al unor soiuri autohtone de struguri de masă

La modification indésirable de la couleur, de la saveur et de la texture du raisin est associée aux enzyme polyphénoloxydase (PPO). Il est donc important de contrôler leur effet et d'établir leurs caractéristiques associées aux fruits. Raisins (peau, pulpe et pepines) de dix cépages roumains pour raisins de table (Splendid, Cetăţuia, Milcov, Transilvania, Someşan, Napoca, Gelu, Coarnă neagră selecţionată, Purpuriu et Radames), ont été analysés pour déterminer l’activité de la PPO, la teneur encomposés phénoliques totaux (flavonoïdes et non-flavonoïdes) et en anthocyanes. La teneur totale en composés phénoliques était plus élevée dans les pepins, allant de 4,36 à 5,35 g équivalent acide gallique/100 g poids frais, dont les flavonoïdes se situaient entre 65 et 88%. L'activité PPO plus élevée a été déterminée dans l’extrait de raisin de la cépage Radames (7,91 U/g/min), tandis que la teneur en anthocyanes totales était plus importante dans les raisins de la cépage Napoca (343,86 mg équivalent cyanidine-3-glucoside/100 g poids frais).Des corrélations négatives plus fortes ont été trouvées entre l’activité PPO et le contenu en anthocyanes (r = -0,9180), ainsi qu’entre l’activité PPO et le contenu phénolique total des peaux de raisin (r = -0,9266)et de la pulpe de raisin (r = -0,9397), suggérant l’effet négative de l'enzyme sur cette classe de composés

Studii privind conţinutul fenolic al frunzelor roşii senescente de viţă de vie – sursă sustenabilă de compuşi cu rol biologic activ

n order to identify new sustainable sources of bioactive compounds for food, pharmaceutical and cosmetic industries, anthocyanin,proanthocyanidin and total phenolic contents of red senescent leaves of 47 grapevine cultivars and chromatic parameters of their alcoholic extracts were evaluated. Leaves were picked between two to eight weeks after grape harvest, the remaining chlorophyll and carotenoid amounts being also quantified. Red grapevine leaves showed high antioxidant activity (% scavenged DPPH), proportionally correlated with the concentration of anthocyanins and total phenolic compounds. Chlorophyll and carotenoid content of red leaves was low, without exceeding 1.56mg/g and 0.92mg/g dry weight, respectively. High amounts of antioxidant anthocyanins, proanthocyanidins and total phenolic compounds, as well as the chromatic diversity of the obtained extracts, justify the use ofsenescent red grapevine leaves as raw material in the production of valuable dietary supplements

Evaluarea conţinutului de 5-hidroximetilfurfural al unor vinuri albe seci şi îndulcite

5-Hydroxymethylfurfural (HMF) is a water-soluble compound resulting from heating monosaccharides in acidic conditions (e.g. wine pasteurisation), potentially carcinogenic to humans. White wines obtained through classical winemaking technologies and subsequently pasteurised were assessed for their HMF content by UV-vis spectrometry. Different volumes of oversulfited and concentrated musts were added to increase the concentration of sugars in wines (10 to 50 g/L). Samples were subjected to heat treatment (45- 100°C) in time intervals correlated with temperature (<120 min). Pasteurised dry wines showed low HMF levels of 1.09-3.14 mg/L. HMF content of traditionally “mulled” wine was the highest in samples sweetened to 100 g/L sugars boiled for 10 minutes (>181mg/L). The HMF content in dry and sweetened white wines was correlated with high sugar content, high acidity, high temperature and a long heating time, normal pasteurisation (75°C, 1-2 min) leading to lower HMF amounts

Valorificarea reziduului vegetal de seminţe de struguri rezultat din procesele extractive ale compuşilor fenolici

The stepwise extraction process of phenolic compounds from grape seeds ultimately leads to the production of a residue rich in protein, cellulose and substances without nitrogen which can be biodegraded in nature by microorganisms from the soil. The purpose of this research was to verify whether the vegetable residue of grape seeds, resulting from the extraction of polymerized proanthocyanidins can be used as an organic fertilizer in the soil. The soil biodegradation process was assessed by microbiological analysis and analysis of current and potential dehydrogenase activity. The results obtained showed that the vegetal residue led to the increaseof the number of soil microorganisms involved in the nitrogen circuit and carbon, as a result of the triggering of the biodegradation process as well as its non-polluting effect supported by current and potential dehydrogenase activity determined in dynamicsover a year in experimental plots

Studii privind gradul de asemănare fenotipică dintre unele soiuri autohtone de viţă de vie prin utilizarea metodelor statistico-matematice

Use ofstatistical mathematical methods in the characterization of cultivarsand determination of theirdegree of similarity provides important information concerningcultivarsappurtenanceto different sortogroups, the degree of relatedness between cultivarsand their differentiation. The purpose of this study was to determine the degree of phenotypic similaritybetween 11 autochthonous grapevine cultivarsbased on the physico-mechanical, biochemical and physiological characteristics of grapes and leaves, using Cluster analysis, which admits the existence of polythetic groups and allows verificationof genotype belonging to a varietal faction. Group with the lowest chaining index, indicating a highphenotypic similarity,was Coarnăneagră~ Coarnăneagrăselecţionată, followed by Purpuriu ~ Cetăţuia and Someşan ~ Milcov groups, fact justified by their common origin within thegroup. A lower degree of similarity was notedbetween Purpuriu and Radames cultivars,with Villard blanc as commongenitor, and betweenTransilvania and Splendid cultivars (commongenitor Black rose)

Activitatea antimicrobiană a unui bioprodus biologic activ obţinut din seminţele de struguri

At the Research Station for Viticulture and Enology Iasi, a polymeric condensed proanthocyanidins was obtained from Fetească neagră grape seeds, through a phase preparation, which under determined conditions with hydrogen peroxide, led to the production of a water-soluble bio product with antibacterial, antifungal and antioxidant properties. Evaluation of the antimicrobial activity of the bio product was performed by determining minimum inhibitory concentration (MIC) and minimal bactericidal concentration (CMB) against Staphylococcus aureus and Escherichia coli. From the analysis of the obtained data it was found that the bio product reacted differently from the tested species, being more active against Staphylococcus aureus (G +). The determined MIC was 1.5 mg/mL and the CMB 2.0 mg / mL. In the case of the Escherichia coli (G-) test, the MIC and CMB values were equal but increased to 3.0 mg/mL

Assessment of the technological performance of some Saccharomyces and non-Saccharomyces indigenous yeast strains

The study aimed to assess the technological potential of four indigenous Saccharomyces cerevisiae strains (S. cer. 4.1.11, S. cer. 4.3, S. cer. 4.6 and S. cer. 4.10), as possible sources for starter cultures. The experiments were carried out at micropilot level on the natural must of 'Fetească albă' cultivar. The evaluation of the yeasts was carried out according to the chemical parameters and volatile compounds analysed in the obtained wines compared to the wine obtained with a commercial starter culture (CSC). The values of the main physico-chemical parameters analyzed in the obtained wines were similar to those determined in the control wine. The average values of the volatile compounds with positive impact on the wine aroma ranged within the interval 177.46 - 217.81 mg/L, a higher value compared to the control wine, respectively 166.33 mg/L. The use of the indigenous strain Torulospora delbrueckii (T.d 10) in association with the strains S. cer. 4.1.11 or S. cer. 4.10 led to an increase of 12.56%, respectively 8.30% in glycerol concentrations, as well as an increase of 11.94% to 14.49% in the average concentration of volatile compounds. Harnessing the oenological potential of the yeasts tested in sequential fermentations proved dependent on the time allowed for the development of the strain T.d 10, namely 24 and 48 hours, as well as on the yeasts used. Thus, in the wines obtained by the association T.d 10/ S. cer. 4.10, in which the development of the culture T.d 10 was carried out for 48 hours, we noticed an increase of 12.52% and, respectively 32.95%, in the average of volatile compounds, compared to the monoculture wine for the same S. cer. 4.10 strain and to the control wine (CSC)