Thick Juice Research Articles

Reduction of Turbidity of Beet Sugar Solutions by Mechanical and Chemical Treatment

Abstract The presence of practically non-dissolvable small particles in sugar solutions can cause haze during application and has to be minimal. Intermediate storage of thick sugar juice becomes increasingly common practice. In particular juices treated with anti-scale agents appear to be prone to turbidity development. This work on turbidity mitigation reports results on both laboratory and industrial level experiments. Different filter aids were tested and led to reduced turbidity levels. At industrial and lab scale reductions in the order of 30–54% and 50–70% were achieved respectively, which however remains insufficient to resolve the problem. The chemical mitigation by reduction of the hardness of the juice either by sodium carbonate or by ion exchanger treatment was investigated. While the reduction of the calcium concentration by dosing of sodium carbonate turned out to be basically possible, this remains less practical than the utilization of cation exchangers. Furthermore, it was found that application of anti-scale agents causes a reduction on the particle sizes that are found in thick juice samples after 2 months storage. Turbidity values of these samples were, independent of dosage and type of anti-scale agent, twice as high as in reference samples.

Assessing the potential of wild yeasts for bioethanol production.

Bioethanol fermentations expose yeasts to a new, complex and challenging fermentation medium with specific inhibitors and sugar mixtures depending on the type of carbon source. It is, therefore, suggested that the natural diversity of yeasts should be further exploited in order to find yeasts with good ethanol yield in stressed fermentation media. In this study, we screened more than 50 yeast isolates of which we selected five isolates with promising features. The species Candida bombi, Wickerhamomyces anomalus and Torulaspora delbrueckii showed better osmo- and hydroxymethylfurfural tolerance than Saccharomyces cerevisiae. However, S. cerevisiae isolates had the highest ethanol yield in fermentation experiments mimicking high gravity fermentations (25 % glucose) and artificial lignocellulose hydrolysates (with a myriad of inhibitors). Interestingly, among two tested S. cerevisiae strains, a wild strain isolated from an oak tree performed better than Ethanol Red, a S. cerevisiae strain which is currently commonly used in industrial bioethanol fermentations. Additionally, a W. anomalus strain isolated from sugar beet thick juice was found to have a comparable ethanol yield, but needed longer fermentation time. Other non-Saccharomyces yeasts yielded lower ethanol amounts.

Microbiology of sugar-rich environments: diversity, ecology and system constraints.

Microbial habitats that contain an excess of carbohydrate in the form of sugar are widespread in the microbial biosphere. Depending on the type of sugar, prevailing water activity and other substances present, sugar-rich environments can be highly dynamic or relatively stable, osmotically stressful, and/or destabilizing for macromolecular systems, and can thereby strongly impact the microbial ecology. Here, we review the microbiology of different high-sugar habitats, including their microbial diversity and physicochemical parameters, which act to impact microbial community assembly and constrain the ecosystem. Saturated sugar beet juice and floral nectar are used as case studies to explore the differences between the microbial ecologies of low and higher water-activity habitats respectively. Nectar is a paradigm of an open, dynamic and biodiverse habitat populated by many microbial taxa, often yeasts and bacteria such as, amongst many others, Metschnikowia spp. and Acinetobacter spp., respectively. By contrast, thick juice is a relatively stable, species-poor habitat and is typically dominated by a single, xerotolerant bacterium (Tetragenococcus halophilus). A number of high-sugar habitats contain chaotropic solutes (e.g. ethyl acetate, phenols, ethanol, fructose and glycerol) and hydrophobic stressors (e.g. ethyl octanoate, hexane, octanol and isoamyl acetate), all of which can induce chaotropicity-mediated stresses that inhibit or prevent multiplication of microbes. Additionally, temperature, pH, nutrition, microbial dispersion and habitat history can determine or constrain the microbiology of high-sugar milieux. Findings are discussed in relation to a number of unanswered scientific questions.

Dynamics of calcium L-lactate fermentation by Lactobacillus rhamnosus in sugar beet thick juice and glucose based media

The Mascletàs are high-intensity pyrotechnic events, typical of eastern Spanish festivals, in which thousands of firecrackers are burnt at ground level in an intense, short-time (<8 min) deafening spectacle that generates short-lived, thick aerosol clouds. In this study, the impact of such events on air quality has been evaluated by means of particle number concentration measurements performed close to the venue during the June festival in Alicante (southeastern Spain). Peak concentrations and dilution times observed throughout the Mascletàs have been compared to those measured when conventional aerial fireworks were launched 2 km away from the monitoring site. The impact of the Mascletàs on the total number concentration of particles larger than 0.3 μm was higher (maximum ∼2·104 cm-3) than that of fireworks (maximum ∼2·103 cm-3). The effect of fireworks depended on whether the dominant meteorological conditions favoured the transport of the plume to the measurement location. However, the time required for particle concentrations to return to background levels is longer and more variable for firework displays (minutes to hours) than for the Mascletàs (<25 min).

Stable high-titer n-butanol production from sucrose and sugarcane juice by Clostridium acetobutylicum JB200 in repeated batch fermentations.

The production of n-butanol, a widely used industrial chemical and promising transportation fuel, from abundant, low-cost substrates, such as sugarcane juice, in acetone-butanol-ethanol (ABE) fermentation was studied with Clostridium acetobutylicum JB200, a mutant with high butanol tolerance and capable of producing high-titer (>20 g/L) n-butanol from glucose. Although JB200 is a favorable host for industrial bio-butanol production, its fermentation performance with sucrose and sugarcane juice as substrates has not been well studied. In this study, the long-term n-butanol production from sucrose by JB200 was evaluated with cells immobilized in a fibrous-bed bioreactor (FBB), showing stable performance with high titer (16-20 g/L), yield (∼ 0.21 g/g sucrose) and productivity (∼ 0.32 g/Lh) for 16 consecutive batches over 800 h. Sugarcane thick juice as low-cost substrate was then tested in 3 consecutive batches, which gave similar n-butanol production, demonstrating that JB200 is a robust and promising strain for industrial ABE fermentation.

Thick Juice-Based Production of Amino Acihttp://www.omicsonline.org/open-access/thick-juice-based-production-of-amino-acids-2155-952X-4-167.php?aid=34446ds and Putrescine by Corynebacterium glutamicum

Thick juice (also regarded as syrup) is an intermediate product of sugar processing. It is cheaper than processed sugar and is mainly composed of sucrose. Sucrose is a preferred carbon source of Corynebacterium glutamicum, a workhorse of biotechnology used for million-ton-scale amino acid production. Here, it is shown for C. glutamicum that sugar beet thick juice led to higher growth rates and faster carbon source consumption than pure sucrose. Comparative DNA microarray analysis revealed differential expression of genes for butyrate and citrate catabolism and of NAD and biotin biosynthesis suggesting provision of these compounds by the thick juice. Thick juice was also shown to be superior to sucrose in production of the amino acids L-lysine, L-glutamate and L-arginine as well as of the diamine putrescine since higher volumetric productivities than with pure sucrose could be achieved. Taken together, sugar beet thick juice was shown to be a carbon source for growth and amino acid and diamine production of C. glutamicum superior to pure sucrose.

Automatic backwash filter for thick juice filtration

Within nearly every production process there are two crucial targets. On the one hand, improvement of product quality and increase of process efficiency, on the other hand optimization of cost efficiency and savings in running costs. In this paper a process step where both targets could be influenced is discussed, namely thick juice filtration, which is an essential step during the sugar manufacture. Four different technologies are reviewed and compared with each other in detail. Three of them are already established in filtration of thick juice, while the fourth one is quite new and, in various aspects, a promising alternative.

Sugar beet syrups in lactic acid fermentation – Part I

Biotechnological production of lactic acid has been studied in various ways, e.g. microorganisms, fermentation processes, down-stream processes, fermentation substrates, and fermentation nutrients. The problems for all processes still are high costs for feedstock and fermentation nutrients. The objective of this study is a general evaluation of sugar beet thick juice from Pfeifer &amp; Langen GmbH &amp; Co. KG, Germany as a substrate for lactic acid production. In a series of fermentation experiments the results based on thick juice were comparable to those obtained using cane raw sugar and even better than using conventional corn starch as a fermentation subtrate. The most important findings for a later technical application are the high volumetric productivity (up to 5.5g·L–1·h–1), and the optical purity of the lactic acid (&gt;99% ee l-LA).

Sugar beet syrups in lactic acid fermentation – Part II Saving nutrients by lactic acid fermentation with sugar beet thick juice and raw juice

Renewable feedstock gain increasing attention in a time of rising oil prices and uncertainty about security of supply. Often those alternative resources do have high prices and processing costs. Fermentation processes are still of major significance in biotechnological processes. Sourcing cheap raw materials is a task of agricultural businesses. Apart from feedstock costs, energy and nutrients show a great impact on process economics. This actual study explores the potential of sugar beet thick juice and raw juice to act in a bifunctional manner, either as substrate or nutrient. Key finding of this studies are that even in absence of additional nutrients with raw juice lactic acid yields of up to 51,5% compared to 13,5% with thick juice and 2,4% with crystalline sugar were obtained. Even with raw juice an enentoermic purity of l(+)-lactic acid &gt;98% could be achieved. The analytical comparison shows that raw juice can provide significant share of amino acids of a typical yeast extract addition while crystalline sucrose shows no contribution.

Evaluation of the fermentation of high gravity thick sugar beet juice worts for efficient bioethanol production

BackgroundSugar beet and intermediates of sugar beet processing are considered to be very attractive feedstock for ethanol production due to their content of fermentable sugars. In particular, the processing of the intermediates into ethanol is considerably facilitated because it does not require pretreatment or enzymatic treatment in contrast to production from starch raw materials. Moreover, the advantage of thick juice is high solid substance and saccharose content which eliminates problems with the storability of this feedstock.ResultsThe objective of this study were to investigate bioethanol production from thick juice worts and the effects of their concentration, the type of mineral supplement, as well as the dose of yeast inoculum on fermentation dynamics and ethanol yield.The obtained results show that to ensure efficient ethanolic fermentation of high gravity thick juice worts, one needs to use a yeast strain with high ethanol tolerance and a large amount of inoculum. The highest ethanol yield (94.9 ± 2.8% of the theoretical yield) and sugars intake of 96.5 ± 2.9% were obtained after the fermentation of wort with an extract content of 250 g/kg supplemented with diammonium hydrogen phosphate (0.3 g/L of wort) and inoculated with 2 g of Ethanol Red dry yeast per L of wort. An increase in extract content in the fermentation medium from 250 g/L to 280 g/kg resulted in decreased efficiency of the process. Also the distillates originating from worts with an extract content of 250 g/kg were characterized by lower acetaldehyde concentration than those obtained from worts with an extract content of 280 g/kg.ConclusionsUnder the favorable conditions determined in our experiments, 38.9 ± 1.2 L of 100% (v/v) ethyl alcohol can be produced from 100 kg of thick juice. The obtained results show that the selection of process conditions and the yeast for the fermentation of worts with a higher sugar content can improve the economic performance of the alcohol-distilling industry due to more efficient ethanol production, reduced consumption of cooling water, and energy for ethanol distillation, as well as a decreased volume of fermentation stillage.

Integration of Biohydrogen Production with Heat and Power Generation from Biomass Residues

The employment of renewable sources rather than fossil fuels in the production of hydrogen is an important step to achieve a sustainable hydrogen economy in the future. Besides biomass gasification, production of hydrogen from renewable sources is also possible in a fermentative way through thermophilic (dark) fermentation and/or photo-heterotrophic fermentation. Depending on pretreatment procedure, considerable heat demand is necessary to produce hydrogen from agricultural residues and food processing. While heat demand in the pretreatment step can be reduced by heat integration measures, significant heat input is still necessary in the dark fermentation step. The paper evaluates possible contributions of utilizing process residues to cover the heat demand of the biohydrogen production. Process options for three types of feedstock for biohydrogen production have been investigated towards the potential of heat self-supply of the process. Results show that the heat demand of biohydrogen production from barley straw and potato steam peels can be covered from heat of biogas utilization obtained from process residues. For feedstock thick juice still a heat deficit of 0.29 MW is observed.

Hydrogen production from sugar beet molasses – a techno-economic study

Abstract Two-stage fermentative hydrogen production process comprising dark fermentation and photofermentation followed by gas upgrading is studied from the technical and economic points of view. It is assumed that a conceptual hydrogen plant is connected to a sugar factory so that technical sucrose solutions produced there (raw juice, thick juice and molasses) can be used as fermentation feedstocks. Process data needed for the study are based on the results of a recently completed research project and in the techno-economic assessment of hydrogen production, data acquired in the sugar industry are taken into account. A parametric study of the cost of hydrogen production from molasses shows that the total cost is highly sensitive to the capital and operating costs of the photofermentation stage. Prospects of cost reduction through further development of the two-stage fermentative process are discussed.

Determination of suitable storage conditions to preserve fermentable sugars in raw thick beet juice for ethanol production

New long-term storage techniques are necessary to preserve fermentable sugars from sugar beet (Beta vulgaris L.) varieties which may qualify as advanced biofuel feedstocks in the United States. The focus of this study was to evaluate the combined effect of pH and refractometric dissolved solids (RDS) content on fermentable sugar preservation in raw thick beet juice stored for 24 wk at 23 ± 1 °C. Response surface methodology was applied to model the change in fermentable sugars in raw thick juice stored under controlled acidic (2 ≤ pH ≤ 5) and alkaline (8 ≤ pH ≤ 11) conditions in combination with RDS weight fractions in the range of 60–69%. Combinations of pH ≤ 3.5 or pH ≥ 9.5 with RDS ≥ 64.5% were effective in preserving up to 99% of fermentable sugars in stored raw thick juice. Following storage, yeast fermentation of acidic treatments achieved efficiencies of up to 82% relative to raw juice, whereas yeast fermentation was hindered in alkaline treatments resulting in efficiencies of up to 54%.

’Propylene glycolate’ used as a top coat seal to protect thick juice from degradation in ellipsoidal storage tanks

The use of sodium propylene glycol for thick juice storage was investigated at Spreckels Sugar Company, in Brawley, California (USA). Sodium-polypropylene glycol has a density of 1.07 and does not mix with thick juice. Therefore it is suitable as a barrier layer. Chemical properties of propylene glycol, and the deposition on the top of thick juice are described. First results of the last campaign are compared with data from previous years. A significantly lower tendency in the reduction of the quality of the thick juice was found.

Continuous ethanol production from sugar beet thick juice by Saccharomyces cerevisiae immobilized onto sugar beet pulp

The immobilization of Saccharomyces cerevisiae onto sugar beet pulp (SBP) by natural adhesion is an efficient and low-cost method for retaining high biocatalyst density in the ethanol fermentation system. In the present study, cells of S. cerevisiae 163, were immobilized by natural adhesion onto SBP. The retention of immobilized cells attained the level of about 1.7?1011 cells/gram of dry SBP. Continuous ethanol production from sugar beet thick juice (TJ) was performed in a cylinder glass bioreactor at a temperature of 30?C and pH 5 during a 27-day period. The stability of the fermentation process at dilution rate (D) of 0.025 h-1 and 0.05 h-1 was evaluated. The yeast-SBP system was shown to be stable for over a 15-day period at the dilution rate of 0.025 h-1, while the dilution rate of 0.05 h-1 was found to be unsuitable due to the intensive yeast leaching from the support. At D of 0.025 h-1 the maximum sugar utilization (Su), ethanol concentration (P), volumetric ethanol productivity (Qp), ethanol yield (Yp/s) and fermentation efficiency were 97.1%, 54.7 g/l, 2.3 g/lh, 0.498 g/g and 97.6%, respectively.

Biohydrogen production by Rhodobacter capsulatus in solar tubular photobioreactor on thick juice dark fermenter effluent

Abstract The purpose of this study was to operate a pilot scale solar tubular photobioreactor (90 L) for photofermentative hydrogen production from thick juice dark fermenter effluent (DFE) by photosynthetic purple-non-sulfur bacterium, Rhodobacter capsulatus. The tubular photobioreactor was equipped with internal cooling tubes for effective temperature control, which is essential for stable, long-term operation. The photobioreactor was operated in fed-batch mode throughout September 2009 in Ankara, Turkey. R. capsulatus had a rapid growth with a specific growth rate of 0.025 h−1 in the exponential phase. The growth was modeled and the parameters were compared with the results obtained in artificial medium. An exponential relationship was found between daily specific growth rates during fed-batch operation and daily total light energy received. The average molar productivity calculated according to daylight time was 0.15 mol H2/(m3 h). The yield obtained was 0.4 mol H2/mol acetic acid consumed. The hydrogen yield factor was related to the daily total light energy received. Acetic acid utilization for different metabolic pathways was investigated. Maximum COD removal efficiency throughout the operation was calculated as 68%. This study showed that sequential operation of dark and photofermentation is a promising route to produce biological hydrogen from thick juice.

Sugar beet pulp as support for Saccharomyces cerivisiae immobilization in bioethanol production

The potential of sugar beet pulp (SBP) and dried sugar beet pulp (DSBP) as economically cheap and renewable supports for immobilization of Saccharomyces cerevisiae cells was investigated. The hydrated supports showed similar cells retention capacities of 0.178±0.038g/g and 0.182±0.041g/g for SBP and DSBP, respectively. The DSBP-immobilized biocatalyst was used for repeated ethanol fermentation, because DSBP is more stable material. Yeast cells immobilization was confirmed by the scanning electron microscopy (SEM). Repeated batch ethanol fermentation of thick juice by yeast immobilized on hydrated DSBP was successfully carried out for at least seven successive cycles without any significant decrease in ethanol production, while in the case of molasses, after the third batch, significant decrease was observed. A maximum ethanol concentration of 52.26±2.0g/l and ethanol yield of 0.446±0.017g/g was achieved in the seventh fermentation batch of thick juice (initial sugar of 120g/l) with almost complete utilization of sugar (97.52±0.15%). The sugar beet thick juice was found to be more convenient industrial substrate for repeated batch ethanol fermentation than molasses and can be used without any nutrient supplementation. The production of bioethanol from sugar beet thick juice and molasses using DSBP-immobilized cell system enables one more opportunity for achieving the zero-waste goal, through a rational use of intermediate and by-products of sugar beet processing.

Artificial neural network approach to modeling of alcoholic fermentation of thick juice from sugar beet processing

In this paper the bioethanol production in batch culture by free Saccharomyces cerevisiae cells from thick juice as intermediate product of sugar beet processing was examined. The obtained results suggest that it is possible to decrease fermentation time for the cultivation medium based on thick juice with starting sugar content of 5-15 g kg-1. For the fermentation of cultivation medium based on thick juice with starting sugar content of 20 and 25 g kg-1 significant increase in ethanol content was attained during the whole fermentation process, resulting in 12.51 and 10.95 dm3 m-3 ethanol contents after 48 h, respectively. Other goals of this work were to investigate the possibilities for experimental results prediction using artificial neural networks (ANNs) and to find its optimal topology. A feed-forward back-propagation artificial neural network was used to test the hypothesis. As input variables fermentation time and starting sugar content were used. Neural networks had one output value, ethanol content, yeast cell number or sugar content. There was one hidden layer and the optimal number of neurons was found to be nine for all selected network outputs. In this study transfer function was tansig and the selected learning rule was Levenberg-Marquardt. Results suggest that artificial neural networks are good prediction tool for selected network outputs. It was found that experimental results are in very good agreement with computed ones. The coefficient of determination (the R-squared) was found to be 0.9997, 0.9997 and 0.9999 for ethanol content, yeast cell number and sugar content, respectively.

Evaluation of an alternative method for the prediction of the technological beet quality

Stagnation of the technological beet quality in Austria has peaked in discussions about methods of calculation used for predicting the same. Consequently, a project was started in 2010 in order to compare various predictive formulas for the technological beet quality on the basis of beet material from a practice variety trial as well as from weekly blended samples collected in the last campaign at Leopoldsdorf and Tulln. The beet material was analyzed for the common quality parameters such as sodium, potassium, -amino nitrogen and sugar content as well as for dry substance for a so-called “refractometer formula”. Finally, results for thick juice purity were calculated with different “classical formulas” and the “refractometer formula”. Comparing these results, the latter delivered the highest values. However, aside from a formula which also takes into account invert sugar, only the “refractometer formula” considerably reacted to decreasing beet quality over the progression of the last campaign. Consequently, it is planned to recalculate the factors of this formula because it is based on a simpler and less time-consuming analytical procedure compared to formulas which take into account invert sugar.

Selection of yeast strains for alcoholic fermentation of sugar beet thick juice and green syrup

Abstract Presented work aimed at determination of effect of various strains of yeast Saccharomyces cerevisiae and concentration of fermentation worts on dynamics and efficiency of alcoholic fermentation. Fermentation worts contained either thick juice or green syrup. It was found that yeast strains designated as M 1 , M 2 and D-2 most efficiently fermented thick juice worts inoculated with yeast cream at a rate of 2 kg m −3 of wort. Fermentation processes lasted for approximately 2 days and ethanol yield approached 92–94% of the theoretical yield. Fermentations of green syrup worts were most efficient (ethanol yield reached 90–92% of the theoretical yield) when these processes were carried out by yeast strains M 1 , M 2 , D-2 and As4 (inoculum – 2 kg m −3 of wort). S. cerevisiae strains M 1 and M 2 dynamically and efficiently fermented thick juice worts with extract of 200 g kg −1 and 250 g kg −1 (89–94% of the theoretical yield) while strain D-2 preferred less dense worts (extract of 200 g kg −1 ) and produced ethanol with the yield of over 92% of the theoretical yield. The optimum green syrup worts extract was 200 g kg −1 .