STUDY ON ALCOHOLIC FERMENTATION IN A STATIONARY BASKET BIOREACTOR WITH IMMOBILIZED YEAST CELLS

The use of a stationary basket bioreactor with immobilized S. cerevisiae cells indicated the possibility to extend the number of alcoholic fermentation cycles that can be carried out with the same biocatalysts to over nine. Although the rates of glucose consumption and ethanol production were lower than those recorded for the mobile beds of immobilized yeast cells, the mechanical lysis of the biocatalysts is avoided in the case of basket bed. Due to the substrate and product accumulation inside the basket bed, the fermentation process can be improved by washing out the biocatalysts bed over two or four cycles

KINETIC STUDIES ON BIODEGRADATION OF LIPIDS FROM OLIVE OIL MILL WASTEWATERS WITH FREE AND IMMOBILIZED Bacillus sp. CELLS

The studies on the biodegradation of lipids from olive oil mill wastewater with free and immobilized Bacillus sp. cells indicated that the maximum specific rate of the process is reached at pH = 8. The use of immobilized cells allows to increasing the number of biodegradation process cycles, but reduces the rate of the process. In this case, the process rate depends on the biocatalysts size and cells concentration inside them. Thus, at bacterial cells concentration of 9 g d.w./100 mL biocatalyst, the apparent specific rate varied from 4.65 to 1.46×10-2 h-1 by increasing the biocatalyst particles diameter from 3 to 4.2 mm.The cumulated influences of the particles size and cells concentration have been included in a mathematical model for the apparent specific rate of lipids biodegradation. The model offers a good concordance with the experimental data, the average deviation being of +/- 7.38%

Las tablillas de Tartaria ¿el primer sistema de escritura?

El Calcolítico en el sureste europeo albergó un número significativo de culturas, pero de entre todas ellas destacamos la cultura Vinča. Esta cultura acentuó su relevancia sobre las demás debido a lo temprana y avanzada que fue en los ámbitos del comercio, la metalurgia y a la complejidad social, lo que pudo conducir al desarrollo de un precoz sistema de escritura. En el trabajo analizaremos algunos de los ejemplos de protoescritura que han llegado hasta nuestros días, concretamente las denominadas tablillas de Tartaria, planteando si podemos referirnos a este sistema de signos como protoescritura, que en cualquier caso es cronológicamente anterior al propio sistema cuneiforme de la civilización sumeria.<br /

Assessment of consumer preferences on table grapes of new Vitis vinifera L. cultivars

Studying consumer behaviour became a concern of grape producers and grapevine breeders since they can learn how consumers choose their products and which are the factors influencing their choice. In this study, 98 respondents from Iaşi County, NE of Romania, aged between 18 and 61 years and grouped in four age categories, were surveyed in order to determine through sensorial analysis their perception on table grapes of seven new Vitis vinifera L. cultivars created in Romania. Respondents’ perception differed with age category. Subjects between 18 and 27 years were the most demanding, grape colour uniformity and aromas being considered very poor. Contrariwise, seeds perception and skin thickness were not assessed as negative features. Respondents from 28 and 35 years appreciated positively the grapes of Napoca and Gelu cultivars, aromatic sensation being noted as very intense for most cultivars. The 36-45 years group considered that grapes of studied cultivars have neutral aroma and seeds perception is unpleasant, grapes of Cetăţuia cultivar being preferred. Respondents between the 46-61 years age group rated positively the grapes of Transilvania and Napoca cultivars, especially for the intensity of aromatic sensation, colour and bloom uniformity. Mean data analysis, revealed that the respondents preferred black grapes with lighter and uniform shades of colour, with large and crunchy berries covered by a uniform wax layer, a balanced sugar/acidity ratio and fewer seeds, grapes of Transilvania cultivar being the closest to their demands. The study revealed that table grapes of the studied V. vinifera L. cultivars created in Romania possess valuable features highly appreciated by consumers and superior characteristics, that can be further use in vine breeding programmes

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 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)

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