Study of some polyphenolic extracts obtained from pressed grape skins

Due to their biologically active properties, polyphenols convert waste into attractive sources for the medical and pharmaceutical products, their traditional management being varied towards other technological processes. The identification of active principles derived from the polyphenolic extracts obtained from pressed grape marc can help create an alternative use and recovery of by-products of wine, fact which increases their economic value. It also helps assess the oenological potential of vine varieties and thus to assess their beneficial properties in maintaining metabolic balance and health of the human body. In this context, the research in this paper aim to characterise the extracts obtained from pressed grape marc by identifying and quantifying the major polyphenolic compounds in their composition. To study the influence of the maceration technology on the content of polyphenolic compounds from byproducts of the winemaking process, grape samples of Fetească neagră, Băbească neagră, Cabernet Sauvignon, Merlot and Arcaş grape varieties were processed using classical maceration, thermo-maceration, microwave maceration and rotary tanks maceration (ROTO-tanks). The obtained polyphenolic extracts were analyzed by high performance liquid chromatography (HPLC), several phenolic acids, stilbenes (trans-resveratrol) non-hydrolysable tannins (catechin and epicatechin), some flavones (rutin and quercitin), and a number of anthocyan compounds being identified and quantified. The results of the preliminary characterization showed quite similar values in the content of total polyphenols and tannoid matters index. The maceration variants did not affect the amount of hydroxybenzoic and hydroxycinnamic acids. The other polyphenolic compounds that were identified varied depending on the grape variety and maceration technology used. The obtained data justifies the use of pressed grape marc as raw material to obtain polyphenolic extracts, recommending further research on its biologically active properties (antiradical, antioxidant, cytotoxic and cytostatic)

Evaluarea şi adaptarea unor metode de extractie a compuşilor polifenolici din semintele de struguri

The extraction of polyphenolic compounds in the plant material is influenced by the chemical and structural characteristics and the particle size of the plant material, as well as the presence of interfering substances. The solubility of the phenolic compounds depends on the solvent used, the degree of polymerization of the compounds, as well as interactions with other plant compounds. The paper presents several methods used for extracting polyphenolic compounds from grape seed: Soxhlet continuous extraction method; extraction with supercritical fluids (liquid CO2); extraction under reduced pressure (3 bar) and high pressure (15 bar) with water and 75% alcohol concentration. Characterization of polyphenolic extracts carried out by HPLC alloweded the recommendation of two methods: with supercritical fluid and Soxhlet method. In the same time it was also observed a higher extraction yelds for the phenolic acids, hydrolysable tannins, flavones of stilbene using alcohol as a solvent

Consideration on stable isotopic determination in Romanian wines

In the last two years, the Oenology Research Centre of Iaşi and the National Institute for Research and Improvement of Cryogenics and Isotopic Techniques of Râmnicu Vâlcea, together with the National Institute for Research and Improvement of the Molecular and Isotopic Techniques of Cluj-Napoca, have begun the implementation of the discriminative isotopic determination techniques for wines, at national level. The paper presented isotopic data regarding the wine made from the native grape variety Fetească albă, cultivated in different vine regions of Romania. The results pointed out the specific characteristics of the region, according to climate and precipitation

Development of the traceability system in the viticultural sector of Romania for improving food safety

Traceability in a food sector can be obtained by developing traceability systems. These systems refer to recording all important data referring to the evolution of a product along the production and supply chain. The benefits derived from the application of this model are great for those involved in the wine production chain (producer, processor and distributor), and for the consumers’ health. Thus, consumers are certain of the safety of the wines they buy, and their right for free choice is ensured by the transparency of the production and marketing chain. Wine producers and processors are more efficient from the viewpoint of products logistics. They might receive fewer complaints from consumers and apply the socalled due diligence defense – the proof they fulfilled their tasks, and they could finally use traceability in marketing to differentiate the products. The benefits for a better protection of public health and traceability help preventing frauds, when the authenticity of certain wines cannot be traced by analyses

THE AROMATIC PROFILE OF WHITE WINES OBTAINED FROM BIODYNAMIC AND CONVENTIONAL GROWN GRAPES IN ROMANIA

This study analyses the differences between wines obtained from grapes cultivated conventionally and those cultivated biodynamically. The wine samples studied were obtained from Rhein Riesling, Italian Riesling, Muscat Ottonel and Chardonnay grape varieties. Among these, four variants (one from each grape variety) were obtained from grapes following conventional cultural technologies, while the rest were from the same grape varieties cultivated biodynamically. All grapes and wines were produced in the Murfatlar vineyard, in south-east Romania. Basic chemical and sensorial analyses were applied to evaluate the differences appearing between the conventional and organic wine samples. All sets of data, PCA analysed, underlined that there are no systematic differences between the two grape cultivation methods and the obtained products

Compounds captured in CO2 Tămâioasa românească Wine fermentation

The volatile aromas that are lost during the must's fermentation into wine represent a department that is not very much analysed. The capturing and analysing of the volatile compounds that are trapped in the CO2 flow during gas exhaustion of the fermentation stage are the main objectives of the present study. The Tamaioasa romaneasca grapes, harvest of 2011, were processed according to the aromatic wine technology During fermentation, the volatile aromatic compounds were captured using SPE cartridges attached to the airlocks of the fermentation vessels. After the fermentation ended, the extracts were obtained by washing the bed of the SPE cartridges with 2 mL diclormethane. Gas-chromatography coupled with mass-spectrometry was used to identify the captured compounds. The processing technologies influenced the number and quantity of the captured compounds. Esters (isobutyl acetate) and alcohols, as well as aldehydes and terpenes are found in the exhaust air of the fermentation process. The identified compounds are found in trace quantities

The aromatic profile of white wines obtained from biodynamic and conventional grown grapes in Romania

This study analyses the differences between wines obtained from grapes cultivated conventionally and those cultivated biodynamically. The wine samples studied were obtained from Rhein Riesling, Italian Riesling, Muscat Ottonel and Chardonnay grape varieties. Among these, four variants (one from each grape variety) were obtained from grapes following conventional cultural technologies, while the rest were from the same grape varieties cultivated biodynamically. All grapes and wines were produced in the Murfatlar vineyard, in south-east Romania. Basic chemical and sensorial analyses were applied to evaluate the differences appearing between the conventional and organic wine samples. All sets of data, PCA analysed, underlined that there are no systematic differences between the two grape cultivation methods and the obtained products