The occurrence of aroma constituents in sparkling wines, with direct impact on their organoleptic characteristics, is affected by several factors, for example the base-wine particularities, grapes cultivar conditions, inoculated yeasts, the aging stage, and wine-making practices. This study evaluated the influence of different four commercial yeasts (IOC FIZZ™, IOC DIVINE™, LEVULIA CRISTAL™, and IOC 18-2007™) on the volatile composition of experimental sparkling wines. For this, five sparkling wines variants from the Muscat Ottonel grape variety were obtained. The base-wine was obtained through reverse osmosis and had a predetermined alcoholic concentration (10.5% vol.). In order to fulfill the proposed purpose, the experimental sparkling wines were characterized by the physical–chemical parameters (according to International Organization of Vine and Wine methods of analysis), volatile fraction (using gas-chromatography coupled with mass spectrometry technique), and sensory descriptors. Data showed a key impact on the concentration of the volatile constituents (p < 0.05), depending on the type of inoculated yeast for the second fermentation. Regarding the sensory analysis, important differences can be observed due to the type of inoculated yeast. Only a minor influence on the physical–chemical parameters was registered.

This work is focused on the study of the influence of different strains of yeasts on the concentration of organic acids, metallic content, and other physical-chemical parameters from experimental sparkling white wines produced by traditional method (bottle fermented). This study was required due to climatic conditions varying from year to year, generating grape harvests with very high alcoholic potential, and very low values for total acidity. In this case, a Muscat Ottonel grape must was used and passed by a reverse osmosis process. The obtained permeate was mixed with a calculated amount of the concentrate to generate a must with a potential of 10.5% (v/v) alcohol, in order o to obtain the base wine for the second fermentation. After fermentation, the wine was treated to get tartaric, protein and microbiological stabilization. For the second fermentation four different strains of yeast species Saccharomyces cerevisiae were used. Bottle fermentation and storage was performed at a constant temperature of approximately 12 • C. After six months of storage, sparkling wine samples were analyzed. The metal content was determined using AAS method, and organic acid concentration was determined by a HPLC method. The main physical-chemical characteristics were determined (alcohol concentration, total acidity, volatile acidity, total dry extract, free SO 2 , total SO 2 , density, pH, conductivity) based on OIV methods. The results obtained indicated significant differences of the analyzed parameters.

Wine is defined as an alcoholic beverage resulted from fermentation of grape must, having ethanol content higher than 8.5% (v/v). Wine consumption has health benefits related to the high concentration of polyphenolic compounds with antioxidant activity and cardiovascular protection effects. However, the alcohol content restricts wine consumption, but wines with low-alcohol content can be obtained with the help of the dealcoholisation process, after it was produced through alcoholic fermentation. The purpose of this work is to evaluate the organic acid concentration, metal content and other physical-chemical parameters of low alcoholic beverages obtained from grape must by a process which involves reverse osmosis, mixing in a variable ratio the permeate and concentrate and then fermentation. For the experiments, a Muscat Ottonel grape must from Iaşi vineyard was used. There were ten variants of beverages (wines) with low alcoholic concentration, by mixing known quantities of the two phases resulting from the reverse osmosis process. These beverages (wines) had an alcoholic concentration starting from 2.5% (v/v) in the first variant, up to 7% (v/v) in the tenth variant. Alcoholic concentration varies for each variant by 0.5% (v/v). After fermentation in 50 L stainless steel tanks, the samples were filtered with 0.45µm sterile membrane and bottled in 0.75 L glass bottles. After 2 months of storage at constant temperature, the beverage samples were analyzed to determine the metal content (AAS method), organic acids concentration (HPLC method), and other physical-chemical characteristics (OIV standard methods). The results obtained indicate that the very complex physical-chemical composition of the low alcoholic beverages analyzed is influenced by the specific chemical composition of a given grape must, as well as by the use of products obtained from reverse osmosis.

Sparkling wine producing and consumption are in constant increase in the last decade and show no sign of slowing. Prior consumption, origin, grape variety, occasion, price and sensorial perception are factors that typically influence wine consumers&rsquo; purchasing and consumption behavior. The presence of volatile compounds in sparkling wines, with direct impact on their organoleptic characteristics, is influenced by several factors, such as the base-wine characteristics, grapes cultivar conditions, the used yeasts, the aging stage or wine-making practices. For this study, five sparkling wines variants from Muscat Ottonel grape variety were obtained. For the experimental samples, the grapes were processed by applying secondary fermentation in bottles. The base-wine was obtained through reverse osmosis and had a predetermined alcoholic concentration (10.5 % vol.). This study aimed to analyze the influence of different commercial yeasts (IOC FIZZ&trade;, IOC DIVINE&trade;, LEVULIA CRISTAL&trade;, IOC 18-2007&trade;) on the volatile composition of experimental sparkling wines. The obtained sparkling wines were characterized by the physical-chemical parameters (according to OIV methods of analysis) and volatile fraction (using gas-chromatography). Data showed an important impact on the concentration of the volatile compounds (p &amp;lt; 0.05), depending on the type of inoculated yeast for the second fermentation and only a minor influence on the physical-chemical parameters was registered.