Extraction of Hemicellulose from Acacia Wood via Autohydrolysis and Ethanol Precipitation

Isolation and utilization of hemicellulose are important processes in the pulp mill-based biorefinery. Considering the potential end use of the hemicellulose,this study investigated the concentration of monomeric and oligomeric sugars in the hydrolysate derived from autohydrolysis of acacia wood and the obtainment of these sugars via ethanol precipitation. The rate of generation of monomers and oligomers increased dramatically with an increase of the temperature from 160℃ to 180℃. The maximum content of oligomers and total sugars was achieved under conditions of 180℃ and 10 min,170℃ and 85 min,respectively. Interestingly,the maximum yield of hemicellulose via ethanol precipitation was achieved in a much shorter time,compared with the maximum yield of oligomer from the hydrolysate by autohydrolysis. A 6. 66 g / L quantity of hemicellulose was obtained by intensifying the conditions of ethanol precipitation. The hemicellulose characteristics were analyzed by Fourier transform infrared,nuclear magnetic resonance,and ultraviolet spectroscopy,and the molecular weight was determined by gel permeation chromatography and thermal analysis.

The Influences of Concentrate Extract Properties and Ethanol Addition Amount on the Ethanol Precipitation Process of Salvia Miltiorrhiza

In this work, 10 batches of Salvia miltiorrhiza concentrate were prepared and purified with ethanol precipitation process. Dry matter content, pH value, conductivity and water content of the concentrates and supernatants were all determined. When more ethanol was used in ethanol precipitation, the pH value of the supernatant generally increased, but dry matter content, water content, and the conductivity decreased. Multivariate linear models were built with the most determination coefficient values greater than 0.7. More than 80% of stachyose was removed in the ethanol precipitation process. The removal rate of fructose, raffinose and sucrose were all higher than 30%. When ethanol addition amount increased, the purity of phenolic acids in the supernatant increased, but the retention of lithosperimic acid and salvianolic acid B decreased. The conductivity and pH value of concentrated extract show relatively small influences on ethanol precipitation indices. When fructose, raffinose, or stachyose contents in the concentrated extract were high, the retention rate of phenolic acids tends to be low on most occasions. The purity and retention rate of phenolic acids in the supernatants were also affected by the purity of phenolic acids in the concentrated. The sugar contents in the concentrate are suggested to be monitored in industry because they significantly affect ethanol precipitation process indices.

Determination of the immunoglobulin G precipitation end-point by an intelligent near-infrared spectroscopy system

Precipitation is a key manufacturing unit during the immunoglobulin G(IgG)production,which guarantees the quality of the final product.Ethanol is usually used to purify IgG during the precipitation process,so it is important to monitor the ethanol concentration online.Near-infrared(NIR)spectroscopy is a powerful process analytical technology(PAT)which has been proved to be feasible to determine the ethanol concentration during the precipitation process.However,the NIR model is usually established based on the specific process,so a universal model is needed.And the clarity degree of solution will affect the quality of the spectra.Therefore,in this study an integrated NIR system was introduced to establish a universal NIR model which could predict the ethanol concentration online and determine the end-point of the whole process.First,a spectra acquisition device was designed and established in order to get high-quality NIR spectra.Then,a simple prepared ethanol NIR model was constructed to predict the actual manufacturing process.Finally,the end-point was determined to stop the peristaltic pump when the ethanol concentration reached 20%.The results showed that the spectra quality was good,model prediction was accurate,and process monitoring was accurate.In conclusion,all results indicated that the integrated NIR system could be used to monitor the biopharmaceutical process to help us understand the pharmaceutical process.

Physicochemical properties and antioxidant activities of polysaccharides extracted from Panax ginseng C.A.Meyer with graded percipitation method

Ginseng polysaccharides were extracted by water decoction from Panax ginseng C.A.Meyer(Cultivated Ginseng),named CGPS.Four polysaccharide fractions,CGPS-20,CGPS-40,CGPS-60 and CGPS-80,were precipitated at final ethanol concentrations of 20%,40%,60%and 80%,respectively.Physicochemical properties,molecular weight,monosaccharide composition and antioxidant capacity of polysaccharide fractions were all investigated.The results indicated that changing the concentration of ethanol could precipitate polysaccharides into fractions with different molecular weights,functional group composition and physicochemical properties,eventually leading to differences in antioxidant activity,which would help to find a simple,efficient,and reliable method for rapid extraction and purification of antioxidant polysaccharides from Panax ginseng C.A.Meyer.Among the four polysaccharide fractions,CGPS-80 had lower molecular weight,higher contents of uronic acid and total phenolic,and stronger scavenging ability on DPPH∙and ABTS∙+radicals.

Enhanced Redispersibility of Cellulose Nanocrystals in Water via Surface Adsorption of Hydrolyzed Sugars from Corresponding Cellulose Nanocrystal Fabrication

Generally,hydrogen bonds are formed between cellulose nanocrystals(CNCs)during their water removal and drying,leading to the irreversible aggregation of CNCs,and thus a poor water-redispersibility.The present study demonstrated a novel approach that involved using hydrolyzed sugars generated from the corresponding CNC production as redispersing agents to enhance the redispersibility of CNCs.Experimental data indicated that hydrolyzed sugars can be adsorbed onto CNCs through ethanol precipitation.The oven-dried CNCs onto which hydrolyzed sugars were adsorbed via ethanol precipitation were homogeneously redispersed in water.The redispersed CNCs showed the particle size distribution,Zeta potential,and thermal decomposition properties similar to those of the CNCs without drying.This method may improve the use of hydrolyzed sugars obtained in the hydrolysate from the corresponding CNC production,as well as facilitate the transportation and storage of CNCs.

Critical process parameter identification of manufacturing processes of Astragali Radix extract with a weighted determination coeffcient method

Objective:Critical process parameters(CPPs)identification is an important step of the implementation of quality by design(Qb D)concept.There are many CPP identification methods,such as risk analysis method,sensitivity analysis method,multiple linear regression method,standard partial regression coefficient(SPRC)method,and so on.The SPRC method can consider multiple process critical quality attributes(CQAs)simultaneously,but the determination of CPP number is subjective.Therefore,new CPP identification method is still required.Methods:The manufacturing process of Astragali Radix extract,which contained water reflux extraction,concentration,and ethanol precipitation,was used as an example.First,the multiple process CQAs were determined to be the yield of pigment,dry matter,sugars,and active ingredients.Second,the potential CPPs were determined by a knowledge organization method.Plackett-Burman designed experiments were then performed.A weighted determination coefficient(R2 w)method was presented to identify CPPs.In this method,the importance of different CQAs was considered.Process parameters were removed one-by-one according to their importance index.The decrease in R2 wwas used to characterize the importance of the removed parameter.If the decrease of R2 wwas less than a preset threshold,the removed parameter was not a CPP.Results:During the manufacturing process of Astragali Radix extract,the potential CPPs determined by the knowledge organization method were water consumption,reflux extraction time,extraction frequency,ethanol content,ethanol consumption,and concentration endpoint.Reflux extraction time,the first ethanol consumption,the second ethanol consumption,and the second ethanol precipitation refrigeration temperature were found to be CPPs using the weighted determination coefficient method with the threshold of 10%.Conclusion:Using the weighted determination coefficient method,CPPs can be determined with all the CQAs considered based on their importance.The determination of CPP number is more objective compared with the SPRC method.

Integration of hemicellulose recovery and cold caustic extraction in upgrading a paper-grade bleached kraft pulp to a dissolving grade

In this study,a hemicellulose recovery process was integrated with a cold caustic extraction(CCE)process in upgrading paper-grade bleached kraft pulp to dissolving grade.Under the conditions of 15%NaOH,10%pulp consistency,30℃and 1 h,a paper-grade softwood bleached kraft pulp was purified to a dissolving-grade pulp with 97.57%α-cellulose and 1.67%pentosan contents.The spent liquor from the cold caustic extraction process was sequentially extracted with ethanol to precipitate and recover the dissolved hemicelluloses,followed by evaporation to recover the ethanol.After the recovery of hemicelluloses and ethanol,the spent liquor can be reused as the caustic solution for the CCE process without compromising the resulting pulp properties.The results demonstrated that it is feasible to integrate hemicellulose production with the cold caustic extraction process of dissolving pulp production,based on the concept of biorefinery.