Feasibility of exhausted sugar beet pulp as raw material for lactic acid production

2020 ◽  
Vol 100 (7) ◽  
pp. 3036-3045
Author(s):  
Ana Belén Díaz ◽  
Claudia González ◽  
Cristina Marzo ◽  
Ildefonso Caro ◽  
Ana Blandino
Foods ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2414
Author(s):  
Cristina Marzo ◽  
Ana Belén Díaz ◽  
Ildefonso Caro ◽  
Ana Blandino

Exhausted sugar beet pulp (ESBP), a by-product of the sugar industry, has been used as a substrate to produce lactic acid (LA). Due to the fact that ESBP contains a high percentage of pectin and hemicellulose, different pretreatments were studied to solubilize them and to facilitate the access to cellulose in the subsequent enzymatic hydrolysis. Several pretreatments were studied, specifically biological, oxidant with alkaline hydrogen peroxide (AHP), and thermochemical with acid (0.25, 0.5, or 1% w/v of H2SO4). Pretreated ESBP was enzymatically hydrolysed and fermented with the strain Lactiplantibacillus plantarum for LA production. The hydrolysis was carried out with the commercial enzymes Celluclast®, pectinase, and xylanase, for 48 h. After that, the hydrolysate was supplemented with yeast extract and calcium carbonate before the bacteria inoculation. Results showed that all the pretreatments caused a modification of the fibre composition of ESBP. In most cases, the cellulose content increased, rising from 25% to 68% when ESBP was pretreated thermochemically at 1% w/v H2SO4. The production of LA was enhanced when ESBP was pretreated thermochemically. However, it was reduced when biological and AHP pretreatments were applied. In conclusion, thermochemical pretreatment with 1% w/v H2SO4 had a positive impact on the production of LA, increasing its concentration from 27 g/L to 50 g/L.


Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2531
Author(s):  
Rodion Kopitzky

Sugar beet pulp (SBP) is a residue available in large quantities from the sugar industry, and can serve as a cost-effective bio-based and biodegradable filler for fully bio-based compounds based on bio-based polyesters. The heterogeneous cell structure of sugar beet suggests that the processing of SBP can affect the properties of the composite. An “Ultra-Rotor” type air turbulence mill was used to produce SBP particles of different sizes. These particles were processed in a twin-screw extruder with poly(lactic acid) (PLA) and poly(butylene succinate) (PBS) and fillers to granules for possible marketable formulations. Different screw designs, compatibilizers and the use of glycerol as a thermoplasticization agent for SBP were also tested. The spherical, cubic, or ellipsoidal-like shaped particles of SBP are not suitable for usage as a fiber-like reinforcement. In addition, the fineness of ground SBP affects the mechanical properties because (i) a high proportion of polar surfaces leads to poor compatibility, and (ii) due to the inner structure of the particulate matter, the strength of the composite is limited to the cohesive strength of compressed sugar-cell compartments of the SBP. The compatibilization of the polymer–matrix–particle interface can be achieved by using compatibilizers of different types. Scanning electron microscopy (SEM) fracture patterns show that the compatibilization can lead to both well-bonded particles and cohesive fracture patterns in the matrix. Nevertheless, the mechanical properties are limited by the impact and elongation behavior. Therefore, the applications of SBP-based composites must be well considered.


2005 ◽  
Vol 53 (23) ◽  
pp. 9017-9022 ◽  
Author(s):  
Liu ◽  
Marshall L. Fishman ◽  
Kevin B. Hicks ◽  
Cheng-Kung Liu

2011 ◽  
Vol 50 (No. 12) ◽  
pp. 553-560 ◽  
Author(s):  
P. Doležal ◽  
V. Pyrochta ◽  
J. Doležal

This study deals with effects of pressing of ensiled sugar-beet pulp and of application of a chemical preservative on the quality of fermentation process. The experimental silages had a better sensory evaluation than the control ones. In silages treated chemically with a mixture of acids, statistically significantly (P < 0.01) higher dry matter content, lowest pH value, the value of lactic acid and the lowest content of all acids in dry matter were found after 180 days of storage from the beginning of the experiment. The statistically significantly (P < 0.01) highest lactic acid content (43.39 ± 1.25 g/kg DM) was determined in the control pressed silage. The highest LA/VFA ratio (1.40 ± 0.18) was calculated for non-pressed experimental silage (D – 3 l/t of KEM). As compared with untreated control the highest percentage (P < 0.01) of lactic acid and of all fermentation acids was found out in silage D treated with 3 l/t of KEM (58.18 ± 0.47 g/kg DM). Undesirable butyric and propionic acids were not found in chemically treated silage samples (C, D, E, F). However, the highest (P < 0.01) contents of butyric acid (26.37 ± 0.91 g/DM) and propionic acid (4.58 ± 0.78 g/DM) were measured in untreated non-pressed silage samples (B). The highest (P < 0.01) contents of acetic acid and ethanol were found in control silage samples. The quality of these silages was evaluated as very low.  


2017 ◽  
Vol 2 (1) ◽  
pp. 13-16 ◽  
Author(s):  
Aladár Vidra ◽  
András József Tóth ◽  
Áron Németh

Abstract Molasses, a by-product of the sugar manufacturing process, generally comprises approximately 50% (w/w) of total sugars, but it is currently used primarily [1] as an animal feed and as a raw material in alcohol production. Currently, the sugar production is more than 160 million tones worldwide. Its byproduct molasses contain heavy metals which have growthinhibitory effect. The main sugar content in molasses is sucrose which often need to be hydrolyzed to glucose and fructose especially for utilization by Lactobacillus species. Lactobacillus species can convert sugar content to lactic acid with great efficiency, which is a valuable chemical. Lactic acid production from sugar molasses using batch fermentations with Lactobacillus casei and Lactobacillus sp. MKT878 were investigated in this study. Results showed, that both examined Lactobacillus species could grow on molasses despite the heavy metals inhibitory effects. The conversion of sugar content to lactic acid was successful with yield between 55-80 g/g.


2007 ◽  
Vol 1 (3) ◽  
pp. 323-330 ◽  
Author(s):  
L. S. Liu ◽  
V. L. Finkenstadt ◽  
C.-K. Liu ◽  
D. R. Coffin ◽  
J. L. Willett ◽  
...  

Author(s):  
Zhao-Qi Zheng ◽  
Yi Liu ◽  
Dong Li ◽  
Li‐jun Wang ◽  
Benu Adhikari ◽  
...  

Abstract Liquefaction of sugar beet pulp (SBP) was carried out using microwave irradiation as the heating source, ethylene glycol/glycerol at a ratio of 80/20 (w/w) as the liquefaction solvent and sulfuric acid as the catalyst at 160 °C. The effects of different liquefaction conditions, including two particle size ranges of SBP, liquefying solvent-to-SBP solids (LS/S) ratio and reaction time on the liquefaction yield, viscosity of the liquefaction products, chemical characteristics and morphology of residues were studied using viscometry, Fourier transform infrared (FTIR), X-ray diffraction (XRD), scanning electronic microscopy (SEM). The efficiency of liquefaction of SBP was found to depend on its particle size of SBP raw material and the LS/S ratio. The smaller SBP particles improved liquefaction efficiency and reduced the amount of solvent required. The crystallinity index of liquefaction residues indicated that crystalline cellulose was no longer the rate limiting factor of liquefaction process when the particle size of SBP was small (75–177 μm). A rugged and deformed surface of the liquefaction residue (observed through SEM) indicated that severe damage in the native fiber structure occurred during the liquefaction.


2020 ◽  
Vol 26 (2) ◽  
pp. 151-156
Author(s):  
Jovan Ciric ◽  
Natasa Jokovic ◽  
Slavica Ilic ◽  
Sandra Konstantinovic ◽  
Dragisa Savic ◽  
...  

Waste glycerol from biodiesel production is a valuable raw material that has been used to produce valuable microbial metabolites. In this work, the possibility of microbial utilization of waste glycerol obtained as a by-product in biodiesel production from sunflower and rapeseed oil by the lactic acid bacterium Enterococcus faecalis MK3-10A on a laboratory level was studied. For comparison, pure glycerol and glucose were used as carbon sources. The kinetics of the microbial biomass growth, the carbon source utilization, and the lactic acid production were monitored. The bacterium E. faecalis MK3-10A better grew in the media with glucose or pure glycerol as a carbon source, but the lactic acid production rate was the highest (14.6 mg/(ml/day)) in the medium with waste glycerol from the sunflower oil-based biodiesel production. Therefore, this waste glycerol might be a promising carbon source for lactic acidbacteria cultivation and lactic acid production.


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