Proizvodnja bioetanola iz ekstrahiranog soka kao međuproizvoda prerade šećerne repe: primjena metode odzivne površine

Response surface methodology (RSM) was used for selecting optimal fermentation time and initial sugar mass fraction in cultivation media based on raw juice from sugar beet in order to produce ethanol. Optimal fermentation time and initial sugar mass fraction for ethanol production in batch fermentation by free Saccharomyces cerevisiae cells under anaerobic conditions at the temperature of 30 °C and agitation rate of 200 rpm were estimated to be 38 h and 12.30 % by mass, respectively. For selecting optimal conditions for industrial application, further techno-economic analysis should be performed by using the obtained mathematical representation of the process (second degree polynomial model). The overall fermentation productivity of five different types of yeast was examined and there is no significant statistical difference between them.Metodom odzivne površine optimirano je vrijeme fermentacije i maseni udjel šećera u hranjivoj podlozi za proizvodnju etanola u kojoj je glavni sastojak sok ekstrahiran iz šećerne repe. Optimalno je vrijeme fermentacije 38 h i početni maseni udjel šećera od 12,30 % u proizvodnji etanola šaržnim uzgojem slobodnih stanica Saccharomyces cerevisiae u anaerobnim uvjetima pri temperaturi od 30 ºC i brzini miješanja od 200 o/min. Da bi se odredili optimalni uvjeti fermentacije u industrijskom mjerilu, potrebno je provesti daljnju tehnološko-ekonomsku analizu primjenom dobivenog matematičkog modela (polinom drugoga reda). Ispitana je produktivnost pet različitih tipova kvasaca i među njima nije utvrđena statistički značajna razlika

Examining submerged and solid-state cultivation course of hydrolytic enzymes production from wheat chaff

Agricultural waste represents an interesting raw material for biotechnological processes nowadays, due to its low price, favorable composition and availability. Wheat chaff, as a lignocellulosic by-product of wheat processing could be a suitable renewable source for producing hydrolytic enzymes for second generation ethanol production technologies. The aim of this work was to investigate the course of Trichoderma reesei cultivation for hydrolytic enzymes production by submerged and solid-state techniques on medium based on wheat chaff. Results show that the monitored values (hydrolytic enzymes activities, total protein content and reducing sugars content) vary significantly with cultivation time, thus there is a need for further optimization of this process parameter

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

Biosynthesis of xanthan gum on wastewater from confectionary industry

Xanthan gum is one of the major commercial biopolymers employed in many industrial processes owing to its unique physical properties such as a high degree of pseudoplasticity and high viscosity even at low concentrations. Commercially available xanthan gum is relatively expensive due to glucose or sucrose being used as the sole carbon source for its production and cost reduction could be achieved by using less expensive substrates, such as food industrial wastewaters. Effluents from the confectionery industry, because of its high organic content, are significant environmental pollutants and before their release into environment it is necessary to purify them. The present study examines xanthan production by Xanthomonas campestris under aerobic conditions on wastewaters from five different factories of the confectionery industry. Xanthan yield was obtained as a quantitative characteristic of the process and was in the range between 4.28 g/L and 10.03 g/L and its quality is determined by following rheological characteristics of obtained cultivation media. The results obtained in this study indicate that wastewater from confectionary industry can be used as the basis of media for the production of this highly valuable product

Biosynthesis of xanthan gum on wastewater from confectionary industry

Xanthan gum is one of the major commercial biopolymers employed in many industrial processes owing to its unique physical properties such as a high degree of pseudoplasticity and high viscosity even at low concentrations. Commercially available xanthan gum is relatively expensive due to glucose or sucrose being used as the sole carbon source for its production and cost reduction could be achieved by using less expensive substrates, such as food industrial wastewaters. Effluents from the confectionery industry, because of its high organic content, are significant environmental pollutants and before their release into environment it is necessary to purify them. The present study examines xanthan production by Xanthomonas campestris under aerobic conditions on wastewaters from five different factories of the confectionery industry. Xanthan yield was obtained as a quantitative characteristic of the process and was in the range between 4.28 g/L and 10.03 g/L and its quality is determined by following rheological characteristics of obtained cultivation media. The results obtained in this study indicate that wastewater from confectionary industry can be used as the basis of media for the production of this highly valuable product

Possibility of crosslinking of raw xanthan with divalent and trivalent metal ions

Biopolymers are biodegradable, biocompatible and non-toxic natural compounds with large molecular masses. Xanthan is a biopolymer produced by bacteria of genus Xanthomonas. Nowadays scientists are focused on examining the possibilities of crosslinking of xanthan using different agents. The aim of this paper was to investigate the possibility of crosslinking of xanthan with divalent and trivalent metal ions. During these studies, xanthan produced by reference strain Xanthomonas campestris ATCC 13951 on medium based on wastewater from white wine production was used. Xanthan solutions of different concentrations (1.0%, 2.0% and 2.5% (w/v)) were prepared in 0.1M sodium chloride. Salts of barium, calcium, magnesium, manganese, zinc, lead, as well as divalent and trivalent iron at different concentrations (0.025 M, 0.050 M and 0.075 M) and pH values (3, 5, 7 and 9) were used. The obtained results indicate that the success of crosslinking and the stability of the formed structures highly depend on the pH value of the salt solutions and the biopolymer concentration. The most stable, solid structures were formed by dropping 2.5% xanthan solution into a 0.075 M solution of FeCl3 at highly acidic pH value. The dry matter content of structures was 2.37%, and average dimensions were about 4.02 x 5.08 mm

Proizvodnja bioetanola iz ekstrahiranog soka kao međuproizvoda prerade šećerne repe: primjena metode odzivne površine

Response surface methodology (RSM) was used for selecting optimal fermentation time and initial sugar mass fraction in cultivation media based on raw juice from sugar beet in order to produce ethanol. Optimal fermentation time and initial sugar mass fraction for ethanol production in batch fermentation by free Saccharomyces cerevisiae cells under anaerobic conditions at the temperature of 30 °C and agitation rate of 200 rpm were estimated to be 38 h and 12.30 % by mass, respectively. For selecting optimal conditions for industrial application, further techno-economic analysis should be performed by using the obtained mathematical representation of the process (second degree polynomial model). The overall fermentation productivity of five different types of yeast was examined and there is no significant statistical difference between them.Metodom odzivne površine optimirano je vrijeme fermentacije i maseni udjel šećera u hranjivoj podlozi za proizvodnju etanola u kojoj je glavni sastojak sok ekstrahiran iz šećerne repe. Optimalno je vrijeme fermentacije 38 h i početni maseni udjel šećera od 12,30 % u proizvodnji etanola šaržnim uzgojem slobodnih stanica Saccharomyces cerevisiae u anaerobnim uvjetima pri temperaturi od 30 ºC i brzini miješanja od 200 o/min. Da bi se odredili optimalni uvjeti fermentacije u industrijskom mjerilu, potrebno je provesti daljnju tehnološko-ekonomsku analizu primjenom dobivenog matematičkog modela (polinom drugoga reda). Ispitana je produktivnost pet različitih tipova kvasaca i među njima nije utvrđena statistički značajna razlika

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

Optimization of cultivation medium composition for production of bioactive compounds effective against Penicillium sp.

Biological control is one of the best alternatives to pesticides as it avoids their weak points in plant disease control. In this study, the composition of cultivation medium for production of bioactive compounds by Bacillus subtilis ATCC 6633 was optimized. The produced bioactive compounds were tested against a phytopathogenic Penicillium sp. known for infesting different agricultural products and causing substantial crop losses. Antimicrobial activity assaying was carried out using the diffusion-disc method, and inhibition zone diameters were measured as direct indicators of antifungal activity. The response surface methodology (RSM) was used to evaluate the effects of different contents of initial nutrients (glycerol, NaNO2 and K2HPO4) in cultivation medium on inhibition zone diameter. Optimization was carried out using the desirability function method in order to maximize bioactive compounds yield and to minimize residual nutrients contents. The optimized concentrations of the selected nutrients in cultivation medium for production of bioactive compounds were: glycerol 20 g/l, NaNO2 1 g/l and K2HPO4 15 g/l

Bioethanol production from milling industry by-product in a laboratory-scale bioreactor

Bioethanol produced by biomass fermentation is a renewable and environmentally friendly energy source and has significant potential as a replacement for liquid fossil fuels. Due to the world moving toward more sustainable energy sources, the production of bioethanol has been steadily increasing. This research aims to investigate the efficiency of bioethanol fermentation from a milling industry by-product in a laboratory-scale bioreactor. Prior to fermentation in a bioreactor, for preparation of a milling industry by-product, two different thermo-enzymatic procedures were investigated and compared, and based on the obtained results the more efficient procedure was selected and used for the experiment in a bioreactor. The bioethanol fermentation was carried out in a 14-litre bioreactor in batch mode under anaerobic conditions at 30°C. The obtained results showed that this by-product can be used for the production of bioethanol but that further optimization is necessary to improve the overall efficiency of the bioprocess