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The high alcohol content in wine usually has a negative impact on its sensory properties, but can also affect the general health of the consumers. The possibility to reduce ethanol production in wines during fermentation involves the use of different yeast strains characterized by the increased production of fermentation by‐products (glycerol, 2,3‐butanediol, etc.) from the available sugar. The activity of these strains should not impair the sensory properties of the wine. In general, the use of genetically and evolutionarily (non‐GM) engineered Saccharomyces cerevisiae strains is still not close enough to commercial application, and therefore, it is unavailable for wine producers. Thus, the aim of this study was to examine the possibility of reducing the production of ethanol in wines using different selected yeast strains (S. cerevisiae, Saccharomyces bayanus, Torulaspora delbrueckii, and Metschnikowia pulcherrima) available at the market. The application of individual yeast and sequential inoculation for wine alcoholic fermentation was examined. The achieved effects were evaluated by determining the content of ethanol, as well as fermentation by‐products (glycerol and volatile acids) and aromatic components in wine samples. Depending on the strain/s used, a decrease in ethanol content of up to 0.9% v/v was recorded in comparison with fermentation by S. cerevisiae alone. The sensory analysis of produced wine showed significant differences in taste and flavor. The results of the experiment conducted at the laboratory level and with the use of sterile must were compared to the ones from the scale‐up experiment in real vinification conditions. The observed differences in the alcohol content of produced wines were significantly lower.

The aim of this study was to assess and compare fermentation characteristics and aromatic profile of plum wines produced with indigenous microbiota and pure cultures of different selected yeast. Experiments were carried out with plum (Prunus domestica L.) varieties of different fruit ripening times (Čačanska rana, Čačanska lepotica, and Požegača). Wine fermentations were conducted by the activity of indigenous microbiota, commercially available Saccharomyces cerevisiae and Saccharomyces bayanus yeast strains and joint activity of Schizosaccharomyces pombe and S. cerevisiae (sequential inoculation). Statistically significant differences in fermentative characteristics and the content of certain volatile compounds were observed as a result of metabolic activity of various indigenous and/or selected yeasts during fermentation of plum pomace. Minimal duration of fermentation (4 to 5 d) and fastest ethanol production rate (from 12.3 to 15.5 g/L/d) were the characteristics of the studied S. cerevisiae strains. Isobutanol, 3-methyl-1-butanol, 1-heptanol, and 1-octanol were the most prevalent higher alcohols in the tested plum wine samples. The predominant ester in plum wines was ethyl acetate, ethyl lactate, amyl acetate, isoamyl acetate, and ethyl palmitate, esters responsible for the floral and fruity olfactory tones, were also present in large amounts. Also, the use of S. cerevisiae strains resulted in the production of plum wines with better sensory characteristics than ones produced with other investigated yeasts. Obtained results are significant since there is limited data on the compounds responsible for the unique flavor of plum wine, as well as on the impact of different yeast starter cultures application on the overall quality of fruit wines.

The operations applied in plum processing and in the production of plum wine can significantly affect the content and activity of biologically active compounds extracted from the raw material. The aim of this study was to assess the composition of phenolic compounds, chromatic characteristics and antiradical activity of plum wines produced from three plum varieties (Čačanska rana, Čačanska lepotica and Požegača) commonly grown in Serbia. Čačanska lepotica wine was characterised by the highest content of total phenols, total anthocyanins and flavan-3-ols, the highest colour intensity (CI) and the strongest antiradical activity against DPPH free radicals. A significant positive linear correlation (r = 0.828-0.905) between the antiradical activity and the content of total phenolics and total anthocyanins was determined. Peonidin-3-glucoside, cyanidin-3-rutinoside, peonidin-3-rutinoside, chlorogenic and caffeic acids and rutin were identified as the main polyphenols in plum wines.

Methanol is natural ingredient of alcoholic beverages and soft drinks; however, the products of its metabolic transformations (formaldehyde and formic acid) are toxic to humans. The aim of this research was to assess the application of different physico‐chemical treatments of pomace in order to find the most efficient method for reducing the methanol during fermentation with the least effect on the sensory properties of the wine. The following procedures were studied: addition of tannins in pomace, addition of phenolic acids, addition of d‐galacturonic and pectic acid, use of bentonite and zeolite, heat treatment of pomace, thermosonication and treatment of pomace with microwaves. Fruit wine used in this study was produced from plums (Prunus domestica L.). Applied treatments showed variable efficiency in reduction of methanol formation in plum wine. It may be noted that the procedures that involved some form of thermal treatment were characterized by a significant decrease in the production of methanol (up to 60–70%) but mostly tended to have a negative impact on the sensory properties of the produced wines. However, exposure of pomace to microwaves for a short time, owing to the contribution of mechanisms of non‐thermal nature (kinetic and chemical), allowed for a significant reduction in methanol formation with a negligible impact on the sensory properties. The decrease in methanol formation during fermentation using tannins, pectic acid, bentonite and zeolite was poor, with only a reduction of up to 15%. Obtained results are significant to the fruit wine and spirit industry, considering the common problem related to an increased content of methanol in these beverages. Copyright © 2016 The Institute of Brewing & Distilling

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A moderate intake of wine is associated with a positive impact on human health owing to the effects of important biologically active components present in the wine in large amounts. The aim of this study was to examine the chemical composition and to assess antimicrobial and cytotoxic activities of fruit wines produced from three plum varieties (Čačanska rana, Čačanska lepotica and Požegača) commonly grown in Serbia as an approach to assess the quality and acceptability of these wines as a functional food. Furthermore, the activity of a series of control samples was assessed in order to determine components from the wine that are responsible for its functional properties. The plum wines produced showed considerable antimicrobial activity against six bacterial and two yeast strains used in this study. In addition to antimicrobial activity, the plum wines showed a significant cytotoxic effect (IC 50 < 50 μg mL À1) on the growth of three tested cancer cell lines (Hep2c, RD and L2OB). Regarding the determined activities, Čačanska rana plum wine achieved the best results. The results indicated that the antimicrobial activity of the plum wines was, in large part, based on the effects of the total acids and the pH value, while the contribution of ethanol and the content of the phenolic compounds were not significant. Similar conclusions were drawn regarding the cytotoxic activity of this fruit wine. The results can be seen as a contribution to the global acceptance of fruit wines as a functional food, with the accent placed on moderate consumption. An important advantage of fruit wines (in particular plum wine), compared with traditional grape wine, is their lower alcohol content. Copyright © 2016 The Institute of Brewing & Distilling Keywords: plum; wine; antimicrobial activity; cytotoxic activity; composition IntroductionIt is known that consumption of certain foods and beverages can have a positive impact on the health of the consumer. Such food is called a functional food because it has a favourable impact on human health in addition to its usual nutritional functions. Grapes and wines naturally contain large amounts of the important biologically active components such as phenolic compounds. In addition to grapes, fruits such as blueberries, blackberries, cranberries, plums etc. are considered to be equal or even better source of various phenolic compounds (1-3). In order to assess the functional value of plum wine, it is necessary to examine its composition and, furthermore, to evaluate its potential antioxidant, antimicrobial and antiproliferative activity. An important advantage of fruit wines, compared with traditional grape wines, is usually a lower alcohol content. Alcohol content is the biggest obstacle to the acceptance of wine as a functional food owing to controversial opinions of the scientific community about its impact on health (4,5).Research on the antimicrobial properties of wine in the last two decades has confirmed its significant activity against a large number of bacteria and yeast species (6-8)....