Dorin Popa

Physical-chemical, biological, and sensory analyses in grape processing using the high frequency electromagnetic field

This paper presents the experimental results of physical-chemical, biological, and sensory analyses, obtained in processing grapes using the high frequency electromagnetic field. We processed the following varieties of grapes: Muscat Ottonel, Merlot, and Pinot Noir (harvested in the Crişana-Santimreu vineyard in 2014).

The effect of pulsed electric field (PEF) treatment on the quality of wine

This paper analyses the influence of applying PEF treatment to mash obtained from red grapes (Pinot Noir and Merlot) on the content of anthocyanins and chromatic properties of wines. Different mechanical and electrical parameters (the distance between the drums, the frequency, and the voltage) have been tested in order to optimize the most effective PEF treatment so that the content of bioactive compounds such as anthocyanins be as high as possible, thus obtaining colour enhancement in the wine. In the case of the tests used, the results indicate that PEF treatment (with the characteristics: the distance between the drums of 2.5 mm, the voltage of 7 kV, the frequency of 178 Hz, and the pulse duration of 150 seconds) lead to a significant increase in the content of anthocyanins and to colour enhancement in both wines. The use of PEF in the winemaking industry is a promising technology that results in obtaining high quality wines.

Microwave-assisted extraction as a method of improving the quality of wines

ABSTRACT The aim of this paper is to study and compare the effect of microwave-assisted extraction (MW) on the content of bioactive compounds (total phenols, flavonoids, and monomeric anthocyanins), antioxidant capacity, chromatic parameters, and sensory properties of wines derived from three varieties of grapes (Muscat Ottonel, Pinot Noir, and Merlot). The applied MW treatment resulted in a more effective extraction of bioactive compounds from grapes that were also found in a large amount in the wine compared to the untreated (control) sample. The antioxidant capacity and colour intensity of the must and wine samples was much higher compared to the control sample. The influence of MW treatment depends on the variety of grapes treated. The results indicate that MW treatment is an appropriate method to produce white and red wine through increased extraction of bioactive compounds and implicitly colour enhancement.

The bioactive compounds, antioxidant capacity, and color intensity in must and wines derived from grapes processed by pulsed electric field

ABSTRACT The aim of this work was to study the effect of pulsed electric field (PEF) treatment on the content of bioactive compounds (total phenols, total flavonoids, monomeric anthocyanin content), antioxidant capacity, color intensity (CI), and sensory quality of wines derived from three varieties of grapes (Muscat Ottonel, Pinot Noir, and Merlot). PEF treatment resulted in an increase in all bioactive compounds, and consequently, an increase in their antioxidant capacity, which was evaluated by different methods. Applying PEF treatment to red grapes resulted in obtaining wines with higher CI compared to the control sample. For a better interpretation of the results and a proper discrimination of the samples in terms of the variety of grapes and PEF treatment, multivariate analyses, such as the principal component analysis, multivariate analysis of variance, and hierarchical cluster analysis, were applied.

ANALYSES OF THE CHANNEL FOR GRAPES AND WINE CAPITALIZATION AND PRODUCTION IN ROMANIA

The production and the capitalization channel of the grapes and wine become efficient when it has an increased level of integration, eliminating as many links that increase the price artificially. The evolution and the integration of a European production and capitalization system, programmed and controlled, will eliminate this situation relatively favourable for the small producer who capitalizes directly the production of grapes or wine evading the control system and the taxes and the contributions owed for the merchandise circulation. The technical and technological endowment is another major problem of the Romanian viticulture and wine-making. The viticulture has an old-fashioned endowment, morally and materially used, energy consuming and inefficient in the matter of costs and quality of the works. There are no specialized firms for the small producers that would perform services and the maintenance is based mainly on the manual work and the work of draft animals. We can find a situation relatively fortunate at the bigger farms where the majority succeeded to be endowed accomplishing an essential condition for the increasing of the economical efficiency by reducing the consumption of manual work. The wine-making represents a major problem for the small producer because of the necessary investments for a performing technological line that becomes efficient only from a total of 50 carriages, which needs a minimum area of 100 ha. Under these circumstances the small producers will resort to traditional wine-making which doesn’t capitalize the staples economically, nor as capability, nor as a matter of quality, and as a consequence the obtained wine is expensive and bad, not having a chance to be capitalized in an organized trade.The production and the capitalization channel of the grapes and wine become efficient when it has an increased level of integration eliminating as many links that increase the price artificially. The evolution and the integration of a European production and capitalization system programmed and controlled will eliminate this situation relatively favourable for the small producer who capitalizes directly the production of grapes or wine evading the control system and the taxes and the contributions owed for the merchandise circulation. The future solution in the case of the small producers is to be associated in a system that would assure the obtaining of grapes of great quality and their industrialization in modern unities with performing technologies obtaining wines with high quality that could compete on a more demanding and more divers market.