Purification of sugar beet vinasse - adsorption of polyphenolic and dark colored compounds on different commercial activated carbons

The adsorption on activated carbons of dark colored compounds contained in sugar beet vinasse was studied. Four commercial activated carbons with different properties (particle size, residual acidity and microporous properties) were respectively checked for efficiency at two temperature levels (25 °C and 40 °C) and at four pH levels (2, 3.5, 7, 10). The adsorption of organic molecules was determined by quantifying the amounts of total polyphenolic compounds and total organic carbon. The results showed that the adsorption capacity of dark colored compounds was enhanced by the decrease in both temperature and pH values of the solution. In this study, it is shown that this capacity depends on activated carbon characteristics which can be classified in the following order: particle size > residual acidity > microporous volume. Three models (Langmuir, Freundlich and Dubinin–Radushkevich) were tested from experimental data and compared. The Langmuir model provided the best correlation on all the activated carbons studied.     

Enzymatic hydrolysis of sugar beet pulp

Summary In order to prepare fermentable sugars from cellulosic raw materials, we have tested the effect of different pretreatments (heat, chemicals, pectinase) on enzymatic hydrolysis of sugar beet pulp. Best results (90% hydrolysis) have been obtained after heat treatment (30 mn at 120°C) with 16 IU.Fp.g^–1 of fresh pulp in 48 hours.     

Enzymic saccharification of sugar beet pulp

Culture filtrates of Talaromyces emersonii UCG 208 grown on beet pulp can convert the polysaccharide components of this agricultural waste to soluble sugars. The saccharification process is facilitated if the pulp is milled or incubated with alkali or peracetic acid before addition of enzyme. However, treatment of unmilled pulp with commercial pectinase prior to incubation with Talaromyces filtrate is also very effective; under suitable conditions, complete hydrolysis of total polysaccharides has been achieved.     

Anaerobic biodegradation of sugar beet pulp

Sugar beet pulp is a by-product of sugar production and consists mainly of cellulose, hemicellulose and pectin. Its composition is suitable for biological degradation. A possible alternative for the utilization of this material (besides cattle feeding) can be anaerobic methanogenic degradation. It has an additional advantage – biogas production. Beet pulp was treated by a two-step anaerobic process. The first step consisted of hydrolysis andacidification. The second step was methanogenesis. In this paper, observation ofthe process of anaerobic degradation and determination of optimal parameters is discussed. A laboratory-scale model for sugar beet pulp anaerobic biodegradation was operated. Results of model performance have shown very good pulp digestion characteristics. In addition, high efficiency removal of organic matter was achieved. Methane yield was over 0.360 m³ kg^-1 dried pulp and excess sludge production was 0.094 g per gram COD added.     

Direct prediction of bioethanol yield in sugar beet pulp using near infrared spectroscopy

Sugar beets are a raw material for the production of sugar and ethanol. The decision on which end product to pursue could be facilitated by fast and reliable means of predicting the potential ethanol yield from the beets. A Near Infrared (NIR) Spectroscopy-based approach was tested for the direct prediction of the potential bioethanol production from sugar beets. A modified partial least squares (MPLS) regression model was applied to 125 samples, ranging from 21.9 to 31.0 gL(-1) of bioethanol in sugar beet brei. The samples were analyzed in reflectance mode in a Direct Contact Food Analyser (DCFA) FOSS-NIRSystems 6500 monochromator, with standard error of cross validation (SECV), standard error of prediction (SEP), coefficient of determination (r(2)) and coefficient of variation (CV) of 0.51, 0.49, 0.91 and 1.9 gL(-1), respectively. The NIR technique allowed direct prediction of the ethanol yield from sugar beet brei (i.e. the product obtained after sawing beets with a proper machine) in less than 3 min.     

Simultaneous saccharification and protein enrichment fermentation of sugar beet pulp

Summary A product with 40 % protein content was obtained from sugar beet pulp (1.25–2.0 mm) in 48 h one stage (simultaneous) saccharification/fermentation process under optimized conditions using a specific enzyme mixture andCandida tropicalis strain, also saving about 40 % enzymes in comparison to a 2-stage process.     

Saccharification and protein enrichment of sugar beet pulp byPleurotus florida

Summary Pleurotus florida was grown in submerged culture with different concentrations of sugar beet pulp with a view to its nutritional upgrading. Micelial growth, protein enrichment and dry weight loss of the solid residues of cultures, as well as the evolution of reducing sugars in the liquid medium, were followed for 14 days. A product with 45% (w/w) protein and a saccharification extent as high as 35% (w/w) were obtained after 7 days with 1% (w/v) sugar beet pulp.     

Continuous anaerobic conversion of sugar beet pulp to biogas

Summary A continuous two step anaerobic digestion of sugar beet pulp as carbon and energy source was carried out. The loading rates in the acidification reactor were varied from 5 g·1^–1·d^–1 to 15 g·1^–1·d^–1 while the hydraulic retention time was in the range of 10 hours to 30 hours; the corresponding values for the methane reactor varied from 2 days to nearly 6 days.With this reactor configuration a biogas yield of more than 85% of the theoretical value for total carbon conversion was achieved resulting in a corresponding COD reduction.     

Oxidative cross-linking of pectic polysaccharides from sugar beet pulp

Oxidative cross-linking of three beet pectin extracts with hydrogen peroxide/peroxidase resulted in an increase in viscosity at low concentrations and in the formation of a gel at higher concentrations. Gels were formed using concentrations of 1.5% for an autoclave preparation and one obtained by an acid extraction and of 3% for a second autoclaved extract. It was shown that in the autoclave extracts only rhamnogalacturonans and possibly the arabinans participated in the cross-linking reaction. Cross-linking of the autoclave extracts with ammonium persulfate resulted in a decrease in reduced viscosity and molecular weight, although ferulic acid dehydrodimers were formed. Treatment of the acid extracted pectin with ammonium persulfate gave a slow increase in viscosity and the formation of a high-molecular-weight population was observed. For both oxidative systems, the 8-5 dehydrodimer was predominant after cross-linking.     

Fractionation of sugar beet pulp by introducing ion-exchange groups

Sugar beet pulp (SBP) was chemically modified with the goal to utilize this method for the preparation of water-soluble polysaccharides. Yields of the trimethylammoniumhydroxypropylated (TMAHP) polysaccharide fractions prepared under vacuum in absence of NaOH or KOH, as well as their molar masses, were higher than those obtained when the samples were only extracted with hydroxide at ambient pressure. The hydroxypropylsulfonated (HPS) fractions extracted at ambient pressure with NaOH had higher yields and molar mass than the TMAHP fractions extracted under vacuum with KOH. Introduction of both ion-exchange groups in one step under vacuum with NaOH gave better yields than with KOH, but smaller than for the solely sulfonated sample. The molar masses of chemically modified fractions were smaller than those extracted only with alkali or water. According to the monosaccharide composition all the fractions are mixtures of arabinogalactans and rhamnogalacturonoans.     

Pectolytic clostridia isolated from sugar beet pulp silages in Italy

Twenty-eight strains of pectolytic clostridia were isolated from sugar beet pulp silages. Seventeen non-pigmented strains were presumed to be Clostridium acetobutylicum ; the remaining 11 pigmented strains were similar to Cl. felsineum. The addition of molasses to sugar beet pulps favoured the growth of other bacteria, particularly lactic acid organisms, whereas pectolytic clostridia were only occasionally found. The pectolytic clostridia promoted the structure loss of simulated silages. The use of molasses in sugar beet pulp ensiling was suggested to prevent texture loss of the ensiled mass.     

Effects of ensilage on storage and enzymatic degradability of sugar beet pulp

Ensiling was investigated for the long-term storage of Sugar Beet Pulp (SBP). Eight strains of lactic acid bacteria (LAB) and a non-inoculated control were screened based on their ability to rapidly reduce pH, produce a large amount of lactic acid and inhibit undesirable fermentations. Lactobacillus brevis B-1836 (LAB #120), Lactobacillus fermentum NRRL B-4524 (LAB #137) and a non-inoculated control were selected for further research to determine the effects of LAB inoculation level and packing density on SBP silage quality and sugar yield upon enzymatic hydrolysis. Both SBP preservation and prevention of cellulose and hemicellulose loss were better when SBP was treated with LAB #137 compared to LAB #120 and the non-inoculated control. Additionally, the ensiling process was found to significantly improve the enzymatic digestibility of SBP by as much as 35%. The results suggest that ensiling may be a promising technology for SBP stabilization and pretreatment for bioconversion to products.     

Synergistic effects of cellulolytic and pectinolytic enzymes in degrading sugar beet pulp

Three cellulases, one hemicellulase and three pectinases were used, separately or in binary and ternary combinations, to hydrolyze dried beet-pulp, a by-product of the sugar industry. By IE-HPLC the compositions and concentrations of the sugars released were determined. The results obtained by enzymatic saccharification were compared to those obtained by acid hydrolysis. The synergistic action of cellulolytic and pectinolytic enzymes in release of total monosaccharides, and of glucose, arabinose and galacturonic acid was also studied. The combination of cellulase, hemicellulase and pectinase, commercially available, was as effective in degrading the beet pulp as the acid hydrolysis. Pectinase appeared to be the most important enzyme, since by hydrolyzing the pectic surface of the lignocellulosic substrate, it favoured the degradation of cellulose and hemicellulose by the respective enzymes.     

甜菜纤维的制备及其性质

甜菜纤维的制备及其性质樊志和周人纲王占武李晓芝韩炜（河北省农林科学院农业物理生理生化研究所,石家庄０５００５１）Ａｐｒａｃｔｉｃａｌｐｒｅｐａｒａｔｉｏｎａｎｄｃｈａｒａｃｔｅｒｉｚａｔｉｏｎｏｆｄｉｅｔａｒｙｆｉｂｅｒｆｒｏｍｓｕｇａｒ┐ｂｅｅｔｐ...     

Valorization of sugar beet pulp through biotechnological approaches: recent developments

Sugar beet pulp (SBP) is a valuable by-product of the sugar beet industry and is predominantly composed of cellulose, hemicellulose, and pectin. It is commonly used as livestock feed because of its palatability, good energy levels, and highly digestible fibers such as pectins and glucans. However, the utilization of SBP for the production of value-added products via biotechnological approaches is gaining significance in recent years owing to its potential as a cost-effective nutrient source and technological advancements in its processing. SBP can be used as a substrate for bio-production of microbial enzymes, single cell protein, alcohols (e.g., ethanol), methane/biogas, hydrogen, lactic acid, ferulic acid, and pectic oligosaccharides. SBP can also be used as a carrier for cell immobilization in fermentation processes. This review focused on recent developments in biotechnological valorization of SBP.

     

Improving the efficiency of enzyme utilization for sugar beet pulp hydrolysis

Sugar beet pulp (SBP) is a carbohydrate-rich residue of table sugar processing. It shows promise as a feedstock for fermentable sugar and biofuel production via enzymatic hydrolysis and microbial fermentation. This research focused on the enzymatic hydrolysis of SBP and examined the effects of solid loading (2–10?%, dry basis), enzyme preparation, and enzyme recycle on the production of fermentable sugars. The enzyme partitioning to the solid and liquid phases during SBP enzymatic hydrolysis and loss during recycling were investigated using SDS-PAGE and Zymogram analysis. Without considering product inhibition, the cellulase added initially to the SBP hydrolysis lost only 6?% filter paper activity and negligible carboxymethyl cellulose activity upon multiple cycles of SBP hydrolysis. It was found that enzyme dosage can be reduced by 50?% while maintaining similar, and in some cases higher fermentable sugar yield. The removal of hydrolysis products will further improve enzymatic hydrolysis of SBP for biofuel production.     

Aqueous ammonia pretreatment of sugar beet pulp for enhanced enzymatic hydrolysis

Bioprocess and Biosystems Engineering - Aqueous ammonia pretreatment under various temperatures was applied to enhance enzymatic hydrolysis of sugar beet pulp (SBP), and the mechanism of...     

Fractional extraction and physico-chemical characterization of hemicelluloses and cellulose from sugar beet pulp

Four hemicelluloses and cellulose fractions were extracted with 10% KOH or 7.5% NaOH at 15°C for 16 h and with 24% KOH or 17.5% NaOH at 15°C for 2 h from defatted, protein and pectin free, lignified or delignified sugar beet pulp (SBP). There was no significant difference in the yield and sugar composition of isolated hemicelluloses and cellulose obtained from four different procedures. 7.5% NaOH extraction at 15°C for 16 h from lignified SBP gave a slightly higher yield of hemicelluloses (10.96%), while 24% KOH extraction at 15°C for 2 h from delignified SBP produced the highest yield of cellulose (18.35%). Molecular-average weights ranged from 88 850 to 91 330 Da for the hemicelluloses obtained from lignified SBP, and 21 620–21 990 Da for the hemicelluloses isolated from delignified SBP. The neutral sugar composition of the hemicelluloses consisted of glucose, arabinose, galactose, xylose, and minor quantities of rhamnose and mannose. The infrared spectra showed an absorption band at 900 cm⁻¹, indicating some amounts of β-linked polysaccharides. Besides ferulic and p-coumaric acids, six other phenolics were also identified in the mixture of alkaline nitrobenzene oxidation of associated lignin in the isolated hemicelluloses and cellulose fractions.     

Selection of preculture conditions for solid state fermentation of sugar beet pulp

Summary For the protein upgrading of sugar-beet pulp in solid state fermentation byTrichoderma reesei andFusarium oxysporum, serveral conditions were studied to prepare an economical preculture for large scale process. The best performance was shown by a preculture obtained in 24 h from 1.5 % molasses solution at pH 4.5–5.0 with 1.0 % milled beet pulp.     

Extraction,characterization and spontaneous emulsifying properties of pectin from sugar beet pulp

The effects of organic acid extractants on the yield and characteristics of pectin from sugar beet pulp were investigated with citric acid, malic acid and lactic acid at different pH (1.5 and 2.0) and time (1 h and 2 h). The results demonstrated that the yields of pectins were directly correlated with the decrease of pH and reaction time, and the optimum yield of 17.2% was obtained at pH 1.5 and 2 h. Furthermore, the acid type also affected the physicochemical characteristics of pectin, especially on the esterification degree (42–71), galacturonic acid content (60.2–77.8%), emulsion activity (35.2–40.1%) and emulsion stability (62.1–79.4%), and a relatively single pectin mainly consisted of homogalacturonan could be obtained under a suitable reaction condition, which was an excellent crude material for the production of emulsion activity.