Vladimir Puškaš

Varietal phenolic composition of Probus, Rumenika and Frankovka red wines from Fruška Gora (Serbia) and changes in main compounds during maceration

Red wine is a rich source of different phenolic compounds which contribute to sensorial characteristics and can exhibit various biological properties. The amount of phenolics in wine depends on various factors such as grape variety, environmental conditions and production technology. The extraction of individual polyphenolic compounds during maceration was investigated in this paper. Preliminary determination of specific phenolic compositions in wines produced from grape varieties characteristic for Fruška Gora region (Probus, Frankovka and Rumenika) was also performed. A general trend in extraction of some compounds as well as specific characteristics for each variety regarding phenolic composition was observed. Obtained results showed that among wines of different varieties and vintages, statistically significant differences existed in the content of most analysed phenolics. Wines made from Probus variety were characterised by very high anthocyanin content and Frankovka wines by high content of syringic acid while high contents of piceid (resveratrol), catechin and gallic acid were specific for Rumenika variety. Obtained results have shown that Probus variety has especially great winemaking potential considering high content of phenolic compounds (especially anthocyanins), as well as intensive and stable colour.

Fermentation Characteristics and Aromatic Profile of Plum Wines Produced with Indigenous Microbiota and Pure Cultures of Selected Yeast

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.

Wastewaters from rose wine production as substrate for xanthan production

Wineries and other grape processing industries annually generate large amounts of solid and liquid waste streams. Winery wastewaters are the waste product of many independent processing and cleaning operations in wineries. As a consequence of the working period and the winemaking technologies, as well as the cleaning practices, volumes and composition of winery wastewaters greatly vary over the year. Due to high organic load, the disposal of these effluents in the environment causes several issues. The bioconversions of winery wastewaters in valuable products are an important alternative to overcome these ecological problems. The aim of this study was to examine the possibility of xanthan production from media based on four wastewaters obtained from different stages of the rose wine production process, i.e. wastewaters collected during the washing of the crusher, press and tanks after clarification of must and fermentation. Process efficacy was estimated based on raw xanthan yield and rheological characteristics of media. In applied experimental conditions, raw xanthan yields were in the range between 8.03 g/L and 17.52 g/L. Also, all cultivation media showed pseudoplastic behavior. Obtained results suggest that wastewaters from rose wine production have a great potential to be used as a substrate for production of this high value biopolymer.

Aromatic compounds of brandies produced from three apricot varieties cultured in Serbia

This study investigated the effect of certain apricot varieties cultured in Serbia on the quality of produced brandies, primarily in terms of the content and relationships of aromatic substances. In this study, fruits of three apricot varieties (NS 6, NS rodna and Ambrozija) were used for production of brandies. Primary fruit processing and distillation were carried out in a distillery of industrial capacity. High differences in the quantity of 14 identified aromatic components of the distillates produced from three apricot varieties were recorded. Ethyl decanoate was present in all three distillates in significantly larger amounts compared to other esters. Ethyl isobutyrate was found in a small amount (0.32 mg/L) in the distillate produced from Ambrozija variety, while in the distillates from other varieties this compound was not detected. The distillates produced from varieties NS6 and NS rodna contained significantly higher amounts of ethyl lactate (12.50 to 13.46 mg/L) compared to the distillate from Ambrozija variety (8.87 mg/L). The content of linalool determined in NS6 distillate was three times higher (22.12 mg/L) in comparison to the distillate from Ambrozija (7.31 mg/L).

The influence of table salt, white sugar and complex bakery additive on the fermentative activity of Saccharomyces cerevisiae

This study determined the influence of the addition of commercial bakery improver (0.1-0.9 %), table salt (1-7 %), and white sugar (1-9 %) into dough on fermentative activity (FA) of yeast, and consequently CO2 production, to improve dough handling and quality of wheat bread by using an optimized additive combination. The FA of yeast cells was evaluated using fermentograph SJA device. The addition of white sugar in the amount of 1-4 % and complex additive in the amount 0.1-0.5 % enhances FA of yeast. Further increase of the amount of these two compounds decreases the FA. The addition of table salt in the amount of 1-7 % negatively affected the FA. The optimal amounts of complex additive, table salt and white sugar, obtained by response surface methodology (RSM) using Design Expert software, which provided maximum FA of 1171.31 ml CO2/gdm/2h were the following: 0.41, 1.0 and 3.91 % based on flour weight, respectively.

Phenolic compounds, chromatic characteristics and antiradical activity of plum wines

ABSTRACT 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.

Extraction of Bioactive Compounds from Grape Processing By-Products

Abstract This chapter denotes the main conventional methodologies for the extraction of valuable, biologically active compounds from grape processing by-products. Grape processing by-products are rich source of various biologically active compounds which can be successfully recovered. Extraction techniques, currently in use, are highlighted in this chapter. Modified conventional extraction methods, such as matrix solid-phase dispersion and enzymes assisted extraction, are also presented. Factors influencing extraction efficiency, such as solvent type, solvent to sample ratio, temperature and pH are described and optimization of experimental parameters is discussed. Various examples of performed extractions are provided. Extracts containing biologically active nutraceuticals, obtained in accordance with described procedures, are suitable for use as natural nutraceuticals, preservatives or colorants in various industrial fields.