Effect of fermentation conditions on content of phenolic compounds in red wine

The evidence of compounds that increase the nutritive value of red wines has been presented in a number of papers. These compounds include catechins and proanthocyanidins among others. Their protective effect on the cardiovascular system and anticarcinogenic properties has been proved. The effect of maceration conditions and increased solid grape parts content, seed in the first place, on the content of phenolic compounds of wine was investigated. Several micro-trials were performed with Cabernet sauvignon sort; in some variants time and temperature of maceration were varied, while the ratio of residual stem and content of seed was increased several times, resulting in a significant change of phenolic compounds content in the obtained wine samples. The presence of ripe stem yielded good results, but only during six days of maceration, while in the case of longer maceration, the change of colour quality was negative. Supplementary quantities of seeds during maceration resulted in an increase of total phenols and catechins. A significant influence on colour of wines was also observed, especially in wines obtained applying shorter maceration

The application of natural organic compounds in bakery industry

Investigations include the analysis of the impact of commercial products: complex additive (0.1, 0.3, and 0.5%), L-ascorbic acid (0.002, 0.004 and 0.012%), diacetyl ester of tartaric acid with monoglycerides (DATEM E472e, 0.1, 0.3, and 0.5%), α-amylase (0.002, 0.006 and 0.012%), xylanase (0.004, 0.012 and 0.024%), alcohol extract of rosemary, thyme or sage (0.5, 1.0 and 2.0%), as well as the combination of complex additive and rosemary, thyme and sage extract on rheological characteristics of dough. The study includes amylograph, farinograph and extensograph analysis of dough with and without additives (control sample). The volume of lost CO2 gas (mL) is the lowest in dough samples with an added combination of complex additive and thyme extract (0.05 and 0.5%) and rosemary extract (2.0%). In the samples with thyme extract (1.0%) added, the volume of lost gas is at a level of samples with added complex additive, DATEM, and L-ascorbic acid

Production of ethanol from Kantata wheat variety

Processing parameters of Kantata wheat variety indicate that it is not suitable for bread making. Therefore, an investigation was carried out to evaluate the suitability of the variety for ethanol production. Wheat was cultivated at the following sites: Kovin, Zrenjanin, Pančevo and Vrbas. Ethanol yields depend on the location on which the samples were grown and on the temperature during thermal and enzymatic preparation of flour samples. Wheat sample cultivated on the Vrbas site gave the highest ethanol yield

Effect of nitrogen sources on the production of antifungal metabolites by Streptomyces hygroscopicus

Biotechnologically produced antifungal compounds for control of plant diseases caused by phytopathogenic fungi represent a promising alternative to synthetic pesticides. Fungi from the genera Alternaria and Fusarium are listed among important storage pathogens of apple fruits. A. alternata causes significant annual losses of apple fruit. Also, F. avenaceum is one of the most commonly encountered Fusarium species identified as the causal agent of a wet apple core rot. Species of the Streptomyces genera are soil bacteria that produce significant quantities of bioactive compounds in appropriate media. Defining the culture medium composition is the basis of bioprocesses development. Nitrogen source is critical component of cultivation medium and also the most useful tool for stimulation of the antifungal metabolites production. The aim of this study was to select the best nitrogen sources in medium for the production of antifungal compounds effective against A. alternata and F. avenaceum by S. hygroscopicus. Activity of the cultivation liquids on A. alternata and F. avenaceum isolates was tested in vitro using well diffusion method. The results in­dicate that maximum inhibition zone was reached in medium with soybean meal as nitrogen source with inhibition diameter more than 35 mm for both tested fungi. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR-31002

The contribution of bioethanol to sustainable development in Serbia

The pollution caused by the use of fossil fuels for the production of mechanical or electrical energy is one of the most important environmental issues nowa­days. In this respect, biofuels represent a viable source of energy. Bioethanol as a renewable energy source is derived from organic material of plant origin, so-called biomass, thus reducing environmental pollution. The aim of this study was to analyze the potential of bioethanol in meeting future energy demands in the Republic of Serbia. [Projekat Ministarstva nauke Republike SRbije, br. TR31002: The improvement of bioethanol production from sugar beet processing products

Effect of the initial glycerol concentration in the medium on the xanthan biosynthesis

This study is concerned with the effect of different initial glycerol concentrations in the medium on xanthan production by Xanthomonas campestris ATCC 13951. Xanthan biosynthesis was carried out in batch mode under aerobic conditions at a temperature of 30oC and agitation rate of 150 rpm for 7 days. The process efficiency was estimated based on the values of raw xanthan yield, average molecular weight of the polymer and residual content of glycerol, total nitrogen and phosphorus. Based on these results, the initial concentration of glycerol as a carbon source in the production medium was suggested. In the applied experimental conditions, high raw xanthan yield (12.15 g/l) of good quality (Mw = 2.86•105 g/mol) and the lowest amount of residual nutrients (glycerol 2.75 g/l, nitrogen 0.46 g/l and phosphorus 0.67 g/l) was achieved in the medium with the initial glycerol content of 20 g/l. The obtained results are the basis for optimization of xanthan production on glycerol containing media in order to increase the product yield and quality

Activation of waste brewer's yeast Saccharomyces cerevisiae for bread production

The waste brewer's yeast S. cerevisiae (activated and non-activated) was compared with the commercial baker's yeast regarding the volume of developed gas in dough, volume and freshness stability of produced bread. The activation of waste brewer's yeast resulted in the increased volume of developed gas in dough by 100% compared to non-activated brewer's yeast, and the obtained bread is of more stable freshness compared to bread produced with baker's yeast. The activation of BY affects positively the quality of produced bread regarding bread volume. The volume of developed gas in dough prepared with the use of non-activated BY was not sufficient, therefore, it should not be used as fermentation agent, but only as an additive in bread production process for bread freshness preservation. Intense mixing of dough results in more compressible crumb 48 hrs after baking compared to high-speed mixing

The biotechnological production of xanthan on vegetable oil industry wastewaters (part II): Kinetic modelling and process simulation

Xanthan is a microbial biopolymer with a wide range of industrial applications and it is expected that the demand for this product will significantly increase in the coming decade and for this reason it is important to constantly work on improving all aspects of this biotechnological process. The aim of this research was to examine the kinetics of batch cultivation of Xanthomonas campestris ATCC 13951 using vegetable oil industry wastewaters as a basis for the cultivation medium, in order to produce the biopolymer xanthan. Kinetic modelling is very important for process control, reducing process costs and increasing product quality. By performing xanthan production on a medium with optimized content, the experimental values of content of biomass, carbon source and the desired product were obtained and used to determine the kinetics of biosynthesis. In order to describe biomass multiplication, product formation and carbon source consumption, the logistics, the Luedeking-Piret and modified Luedeking- -Piret equation, respectively, were successfully used. Additionally, using process simulation software (SuperPro Designer®), a process and cost model for a xanthan production facility was developed. The developed model represents the basis for a 21,294.29 and 23,107.97 kg/year xanthan production facility, which uses a vegetable oil industry wastewater-based medium and a semi-synthetic medium. The simulation model of the suggested xanthan production process, developed and based on defined kinetic models, represents an excellent basis for its further improvement and for increasing its efficiency

The biotechnological production of xanthan on vegetable oil industry wastewaters. Part I: Modelling and optimization

The aim of this research was to examine the possibility of using the vegetable oil industry wastewater as the basis of the cultivation media for xanthan production, using Xanthomonas campestris ATCC 13951, in order to reuse the wastewater obtained in one industry as a raw material in another. Furthermore, the aim was to optimize the composition of wastewater based media in terms of carbon, nitrogen, and phosphorus content. Experiments were carried out in accordance with the Box-Behnken design with three factors on three levels (glucose: 10.00- -30.00 g/L; nitrogen: 0.02-0.20 g/L; phosphorus: 0.0045-0.045 g/L) and three repetitions at the central point. The success of biosynthesis was assessed by analysing broths to determine xanthan yield, cultivation broth apparent viscosity, residual carbon, nitrogen, and phosphorus content. Graphical and numerical optimization using response surface methodology was performed to determine the optimal content values of the carbon source, nitrogen, and phosphorus content. The results of graphical optimization suggest that for the defined response interval values, the defined model predicts that the xanthan production is possible when 15.00-16.00 g/L of the carbon source, 0.02-0.09 g/L of nitrogen and 0.01-0.02 g/L of phosphorus are added to the media that as a basis contains vegetable oil industry wastewater

Optimization of the medium composition for production of antimicrobial substances by bacillus subtilis ATCC 6633

In the effort to overcome the increase in antimicrobial resistance of different pathogens, natural products from microbial sources appear to be the most favorable alternative to current antibiotics. Production of antimicrobial compounds is highly dependent on the nutritional conditions. Hence, in order to achieve high product yields, selection of the media constituents and optimization of their concentrations are required. In this research, the possibility of antimicrobial substances production using Bacillus subtilis ATCC 6633 was investigated. Also, optimization of the cultivation medium composition in terms of contents of glycerol, sodium nitrite and phosphates was done. Response surface methodology and the method of desirability function were applied for determination of optimal values of the examined factors. The developed model predicts that the maximum inhibition zone diameters for Bacillus cereus ATCC 10876 (33.50 mm) and Pseudomonas aeruginosa ATCC 27853 (12.00 mm) are achieved when the initial contents of glycerol, sodium nitrite and phosphates were 43.72 g/L, 1.93 g/L and 5.64 g/L, respectively. The results of these experiments suggest that further research should include the utilization of crude glycerol as a carbon source and optimization of composition of such media and cultivation conditions in order to improve production of antimicrobial substances using Bacillus subtilis ATCC 6633