Xylitol Research Articles

General Method for the Identification of Crystal Faces Using Raman Spectroscopy Combined with Machine Learning and Application to the Epitaxial Growth of Acetaminophen.

Crystal morphology is one of the key crystallographic characteristics that governs the macroscopic properties of crystalline materials. The identification of crystal faces, or face indexing, is an important technique that is used to get information regarding a crystal's morphology. However, it is mainly limited to single crystal X-ray diffraction (SCXRD) and it is often not applicable to products of routine crystallizations becasue it requires high quality single crystals in a narrow size range. To overcome the limitations of the SCXRD method, we have developed a robust and convenient Raman face indexing method based on work by Moriyama et al. This method exploits small but detectable differences in Raman spectra of crystal faces caused by different orientations of the crystallographic axis relative to the direction and polarization of the excitation laser beam. The method requires the compilation of a Raman spectral library for each compound and must be built and validated by SCXRD face indexing. Once the spectral library is available for a compound, the identity of unknown crystal faces (from any crystal that is larger than laser beam) can be inferred by collecting and comparing the Raman spectra to spectra within the library. We have optimized this approach further by developing a machine-learning algorithm that identifies crystal faces by performing a statistical comparison of the spectra in the Raman library and the Raman spectra of the unknown crystal faces. Here, we report the development of the Raman face indexing method and apply it to three different epitaxial systems: Acetaminophen (APAP) grown as an overlayer crystal on d-mannitol (MAN), d-galactose (GAL), and xylitol (XYL) substrates. For each of these epitaxial systems, the crystals were grown under various experimental conditions and have a wide range of sizes and quality. Using the Raman face indexing method, we were able to perform high-throughput indexing of a large number of crystals from different crystallization conditions, which could not be achieved using SCXRD or other analytical techniques.

Highly Flexible and Conductive Glycerol-Doped PEDOT:PSS Films Prepared Under an Electric Field

Poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) films doped with several sugar alcohols, viz. xylitol (XL), glycerol (GL), and polyglycerol (PG), at various levels have been synthesized and their thermoelectric properties studied. Among these specimens, 2.5 vol.% GL-doped films showed the best performance with electrical conductivity σ, Seebeck coefficient S, and power factor S2σ at room temperature reaching 1040 S/cm, 19 μV/K, and 37 μW/m-K2, respectively. Next, we synthesized films under an electric field Epr for the purpose of crystal growth. GL-doped films showed σ enhancement with increase of Epr. The highest σ value of 1300 S/cm was attained at Epr = 4 kV/cm. S and thermal conductivity κ values were almost independent of Epr. The ZT value was calculated to be between 0.017 and 0.101 at room temperature. We also examined film flexibility. High flexibility was achieved on GL doping, and it was not deteriorated when synthesized under an electric field.

Xylitol plant set for Canada

Xylitol plant set for Canada

A Study on Xylitol Based Copolyester for In vitro Degradation Applications

A Study on Xylitol Based Copolyester for In vitro Degradation Applications

Preparation of chitosan/polyvinyl alcohol blended films containing sulfosuccinic acid as the crosslinking agent using UV curing process

This paper reports on a method of preparing chitosan-based films to which sulfosuccinic acid (SSA) is added for crosslinking agent with/without UV curing treatment and applications of a coating materials for foods. The physical, thermal, and optical properties of the UV cured chitosan-based films are investigated including their tensile strength (TS), elongation at break (%E), degree of swelling (DS), solubility (S), and water vapor absorption as well as their biodegradability in soil and applicability of the coating on a fruit. We also evaluated the physical properties of the prepared films to which glycerol (GL), xylitol (XL), and sorbitol (SO) are added to be used as plasticizers. The surface and topography of the prepared films are investigated by scanning electronic microscopy (SEM) and atomic force microscopy analysis (AFM). The results indicate that the films UV cured for 20min possess optimal physical and thermal properties compared to that of non-cured films. The mechanical, thermal, and water barrier properties of SO-added film are also found to be superior to other films with added GL and XL. The degree of biodegradability revealed that the films are degraded by about 40–65% after 220days.

Biomass pyrolysis in a twin-screw reactor to produce green fuels

ABSTRACTThis paper highlights work done with a twin-screw reactor or auger reactor, with temperature profiles of near 500 °C, and sawdust and bagasse biomass. Analysis of the solid biofuel, i.e. biochar, is given, along with proximate and ultimate analysis of biomass feedstocks. System limitations are profiled and issues related to bio-oil production are addressed. Design changes in the existing system are suggested, using SOLIDWORKS software to optimize the existing design where this experimentation has been done. It is believed the design changes would make the facility more efficient. Nitrogen gas is used to maintain the velocity profile of the biomass particles inside the reactor. This work does not have the food vs fodder conflict as the biomass feeds used are primarily wood wastes and sugar industry by-products.

Experimental and Mechanistic Study of the Heterogeneous Nucleation and Epitaxy of Acetaminophen with Biocompatible Crystalline Substrates

The presence of different heterogeneous surfaces can directly influence the nucleation kinetics, crystal growth, and morphology of active pharmaceutical ingredients (APIs). However, a mechanistic understanding of heterogeneous nucleation remains lacking. Herein, we report the use of biocompatible crystalline heterogeneous surfaces to enhance the nucleation rates of the model API compound acetaminophen (APAP). We also report experimental and computational studies of the epitaxial growth mechanism of APAP on different substrates. Five crystalline substrates, namely, d-galactose (DGAL), the α and β forms of d-mannitol (DMAN), α-lactose monohydrate (LMH), and xylitol (XYL) were selected because they contain a similar functionality: a high density of hydroxyl groups per molecule. We measured the induction times in the presence of the substrates and used the results to rank the substrates based on their ability to enhance the nucleation of APAP. While all selected substrates enhanced the nucleation rates, XYL w...

Combination of Entrapment and Covalent Binding Techniques for Xylanase Immobilization on Alginate Beads: Screening Process Parameters

Xylanase are responsible enzyme for hydrolysis of xylan into many beneficial products such as xylose, xylitol and xylooligosaccharides. Due to industrial potential of xylanase, a large number of studies have become interested in their immobilisation to reduce the cost of enzyme. Immobilised enzymes are currently the object of interest due to its benefits over soluble or free enzyme applied in enzymatic hydrolysis. The aims of this study were to determine the suitable method for xylanase immobilisation and to identify the significant parameter which affecting the immobilisation yield by fractional factorial design (FFD). Immobilised xylanase was prepared using a single immobilisation techniques of entrapment and covalent binding and also a combination of entrapment and covalent binding techniques. The immobilisation conditions for xylanase which includes of sodium alginate concentration, calcium chloride concentration, agitation rate and enzyme loading were screened using FFD experimental design to determine the most significant parameters in affecting the efficiency of immobilised xylanase. The analysis of xylanase activity was determined using dinitrosalicyclic acid (DNS) method. The xylanase enzyme was successfully immobilised by entrapment in sodium alginate beads and covalent binding on the surface of beads by glutaraldehyde. The combination of entrapment and covalent binding showed the highest immobilisation yield of 65.81 % compared to a single technique which contributes only 31.99 % and 48.53 %. Glutaraldeyhde concentration showed the most significant parameters compared to the others parameter which gives about 69.01 % of contribution on the xylanase immobilisation yield. The study shows the efficiency of enzyme immobilisation could be improved by a combination of immobilisation techniques and determination of the most significant factors for xylanase immobilisation.

A mild thermomechanical process for the enzymatic conversion of radiata pine into fermentable sugars and lignin

BackgroundConversion of softwoods into sustainable fuels and chemicals is important for parts of the world where softwoods are the dominant forest species. While they have high theoretical sugar yields, softwoods are amongst the most recalcitrant feedstocks for enzymatic processes, typically requiring both more severe pretreatment conditions and higher enzyme doses than needed for other lignocellulosic feedstocks. Although a number of processes have been proposed for converting softwoods into sugars suitable for fuel and chemical production, there is still a need for a high-yielding, industrially scalable and cost-effective conversion route.ResultsWe summarise work leading to the development of an efficient process for the enzymatic conversion of radiata pine (Pinus radiata) into wood sugars. The process involves initial pressurised steaming of wood chips under relatively mild conditions (173 °C for 3–72 min) without added acid catalyst. The steamed chips then pass through a compression screw to squeeze out a pressate rich in solubilised hemicelluloses. The pressed chips are disc-refined and wet ball-milled to produce a substrate which is rapidly saccharified using commercially available enzyme cocktails. Adding 0.1% polyethylene glycol during saccharification was found to be particularly effective with these substrates, reducing enzyme usage to acceptable levels, e.g. 5 FPU/g OD substrate. The pressate is separately hydrolysed using acid, providing additional hemicellulose-derived sugars, for an overall sugar yield of 535 kg/ODT chips (76% of theoretical). The total pretreatment energy input is comparable to other processes, with the additional energy for attrition being balanced by a lower thermal energy requirement. This pretreatment strategy produces substrates with low levels of fermentation inhibitors, so the glucose-rich mainline and pressate syrups can be fermented to ethanol without detoxification. The lignin from the process remains comparatively unmodified, as evident from the level of retained β-ether interunit linkages, providing an opportunity for conversion into saleable co-products.ConclusionsThis process is an efficient route for the enzymatic conversion of radiata pine, and potentially other softwoods, into a sugar syrup suitable for conversion into fuels and chemicals. Furthermore, the process uses standard equipment that is largely proven at commercial scale, de-risking process scale-up.

Hydrothermal co-liquefaction of microalgae, wood, and sugar beet pulp

Hydrothermal co-liquefaction of mixed (wet and dry) biomass residue streams would greatly enhance the viability and scale up potential of the technology as platform in bioenergy and biorefinery applications. This study aims to identify possible interaction effects between three different feeds (protein-rich microalgae, lignocellulosic wood, and carbohydrate-rich sugar beet pulp) and to broaden the data set for evaluating this concept. Co-liquefaction was evaluated at 250 and 350 °C at 10 min of holding time, using 10 wt%( in water) binary mixtures (1:1 wt basis) and a (1:1:1 wt basis) ternary mixture. Results show that interaction during co-liquefaction does play a role and especially reduced the amount of biocrude produced. The biocrude yields obtained are around 15 and 40% below the estimated values for binary and ternary mixtures, on basis of linear averaging the results for the single feeds. For mixtures including algal biomass, a more than proportional nitrogen content and fraction of high molecular mass components was found in the biocrude. For the predictability of biocrude yield and composition in case of biomass mixtures, more work is needed to unravel these interactions.

Productivity, Physicochemical Changes, and Antioxidant Activity of Shiitake Culinary-Medicinal Mushroom Lentinus edodes (Agaricomycetes) Cultivated on Lignocellulosic Residues.

The effects of substrate and strain on productivity, physicochemical characteristics, and compounds with antioxidant activity were evaluated in basidiomes of the shiitake mushroom, Lentinus edodes. Strains IE-245 and IE-256 and the substrates oak wood shavings (OW), sorghum stubble (SS), and sugar cane bagasse (SC) were used. Productivity was evaluated by measuring biological efficiency (BE), production rate (PR), and yield. Total sugars, total soluble solids, pH, titratable acidity, color parameters, total phenolics, flavonoids, ascorbic acid, and antioxidant activity of the basidiomes were measured. BE, PR and yield were higher with the combination IE-256/SS, at 103.71%, 1.32%, and 34.57%, respectively. The largest amount of total sugars (17.61 mg glucose · g-1 dry weight) was found with combination IE-256/SS. Variation was observed in basidiome color; the lowest luminosity (L*) value (darkest color) was found in the IE-256 strain on the OW substrate (L* = 30.45), whereas that of the IE-245 strain on the SC substrate was the lightest in color (L* = 57.00). The largest amounts of total phenolics were recorded in the IE-256 strain on the OW (6.50 mg gallic acid equivalents [GAE] · g-1 dry weight) and the SS substrates (5.85 mg GAE · g-1 dry weight). The best antioxidant activity was obtained with IE-256-0.80, 0.65, and 0.59 μmol Trolox equivalents · g dry weight-1-on the OW, SC, and SS substrates, respectively. Based on the values of BE, PR, and yield, IE-256/SS was the most productive. Substrate and strain, and their interactions, influenced the physicochemical characteristics of the basidiomes and the amounts of compounds with antioxidant activity they contained.

Xylitol production by Candida guilliermondii from fermentation of waste oil palm

La hidrolisis acida diluida del residuo lignocelulosico de raquis de palma de aceite produce azucares fermentables, como la xilosa, principal fuente de carbono para la produccion de xilitol, por Candida guilliermondii . En este estudio, se evaluo el efecto de diferentes medios de cultivo y de condiciones de fermentacion sobre la produccion de xilitol, a partir de raquis de palma de aceite, utilizando C. guilliermondii . El hidrolizado acido de raquis de palma suplementado con 4g/L extracto de levadura, 3g(NH 4 ) 2 SO 4 /L, 0,5g/ MgSO 4 .7H 2 O/L y 0,1gCaCl 2. 2H 2 O/L mostro ser el mejor medio para el crecimiento de la levadura en cultivo sumergido, debido a que presento los valores mayores, estadisticamente significativos, de la velocidad especifica maxima de crecimiento, de 0,12h -1 y produccion de biomasa, de 5,5g/L (p<0,05). Las condiciones de fermentacion mas apropiadas se obtuvieron con hidrolizado de raquis suplementado a pH de 5,5, concentracion inicial de xilosa de 17g/L y un inoculo de 3g/L. La microaerobiosis mostro ser un factor importante en el proceso de fermentacion, con un volumen de 40mL de medio, en un matraz de 100mL, se produjo la mayor concentracion de xilitol de 6,7 g/L (p<0,05).

The formation and physical stability of two-phase solid dispersion systems of indomethacin in supercooled molten mixtures with different matrix formers

Amorphous solid dispersions (SDs) are a promising approach to improve the dissolution rate of and oral bioavailability of poorly water-soluble drugs. In some cases multi-phase, instead of single-phase, SD systems with amorphous drug are obtained. While it is widely assumed that one-phase amorphous systems are desirable, two-phase systems may still potentially exhibit enhanced stability and dissolution advantages over undispersed systems. The objective of the present study was to understand the solid-state properties of two-phase SDs with amorphous drug and their relation to physical stability. Two different types of excipients for SD formation were used, one being a polymer and the other a small molecule excipient. The supercooled molten SDs of a poorly water-soluble indomethacin (IND) with a graft copolymer, Soluplus® (SOL) and sugar alcohol, xylitol (XYL) were prepared. Supercooled molten SDs of IND with SOL were two-phase glassy suspension in which the amorphous drug was dispersed in an amorphous polymer matrix. A short-term aging of the SDs led to the formation of glassy suspensions where the crystalline drug was dispersed in an amorphous polymer matrix. These were physically stable at room temperature for the time period studied (RT, 23±2°C), but aging at high-humidity conditions (75% RH) recrystallization to metastable α-IND occurred. Interestingly, the SDs with XYL were two-phase amorphous precipitation systems in which the drug was in an amorphous form in the crystalline sugar alcohol matrix. The SDs of IND and XYL exhibited fast drug recrystallization. In conclusion, the preparation method of two-phase systems via co-melting in association with the rapid quench cooling is a feasible method for the formulation of poorly water-soluble drugs. The physical stability of these two-phase systems, however, is dependent on the carrier material and storage conditions.

Deposition of nanocomposite coatings on wood using cold discharges at atmospheric pressure

This work examines the synthesis of nanocomposite thin films on wood (sugar maple, Acer saccharum, Marsh) surfaces via a one-step process in an atmospheric pressure dielectric barrier discharge (DBD). More specifically, ZnO-SiO2 nanocomposite coatings are obtained from the atomization in the DBD reactor operated in N2/N2O (Townsend discharge) of a stable colloidal suspension. This suspension is made of crystalline ZnO nanoparticles (NPs) dispersed in hexamethyldisiloxane (HMDSO) and pentane (Pe). Scanning electron microscopy (SEM) combined with energy dispersive X-ray spectroscopy (EDS) show ZnO agglomerates well embedded into a dense SiO2 matrix. The chemical composition and the thickness of the matrix is analyzed through Fourier transform infrared spectroscopy (FT-IR) coupled to ellipsometry measurements. SEM further reveals a lumpy morphology; a feature ascribed to the intrinsic roughness of the wood samples.

Optimization of Acid Treatment of Cashew Peduncle for Ethanol and Xylitol Production

Due to the large amount of waste generated by industries and commitments for environment preservation, there has been a growing interest in the use of alternative energy sources for the production of bioproducts of added value such as ethanol and xylitol. In this context, cashew has been considered a promising alternative to meet the global demand in a more sustainable way. Thus, the aim of this study was to optimize the acid treatment of cashew peduncle for biotechnological production of ethanol and xylitol. Physicochemical analyseswere held for bagasse characterization, and sugars were assessed by HPLC (glucose, xylose and arabinose) and fermentation inhibitors (acetic acid, furfural and hydroxymethylfurfural) in the hydrolyzed liquor. The 23+3 factorial experimental design was applied with a total of 11 experiments to investigate the influence ofvariables temperature, bagasse/acid diluted and acid concentration to evaluate the release of pentoses (xylose and arabinose) and hexose (glucose) in the hydrolyzed liquor. The liquor from the acid treatment should operate under ratio conditions temperature at level +1 (160 °C), acid concentration and bagasse:diluted acid at level -1 (1% and 1:6), obtaining pentose yields (xylose and arabinose). It was observed that acid treatment liquor is very effective in providing high-susceptibility substrates for ethanol and xylitol production.

Comparative evaluation of 0.2% Chlorhexidine Mouthwash, Xylitol Chewing Gum, and Combination of 0.2% Chlorhexidine Mouthwash and Xylitol Chewing Gum on Salivary Streptococcus mutans and Biofilm Levels in 8- to 12-Year-Old Children.

AimTo assess the effect of combining 0.2% chlorhexidine (CHX) mouthwash with xylitol (XYL) chewing gum on Streptococcus mutans and biofilm levels among 8- to 12-year-old children.Materials and methodsSixty children aged 8 to 12 years were selected with moderate and high salivary S. mutans levels. They were divided into three groups of 20 children each: (1) XYL group where the subjects chewed XYL twice daily; (2) CHX where rinsing was done twice daily; and (3) combination of XYL and CHX group (XYL+CHX) where both the agents were used once daily. The S. mutans colony-forming units (CFUs) were counted by using the mitis salivarius agar plate at the beginning of the study and at 15 days, 1, 2, and 6 months from the start of the study.ResultsThe XYL+CHX group showed the maximum reduction in both the biofilm and S. mutans scores throughout the study period.ConclusionThe XYL+CHX combination reduced both the biofilm and S. mutans score significantly better than either XYL chewing gums or CHX mouthwash used alone.How to cite this articleSyed M, Chopra R, Shrivastava V, Sachdev V. Comparative evaluation of 0.2% Chlorhexidine Mouthwash, Xylitol Chewing Gum, and Combination of 0.2% Chlorhexidine Mouthwash and Xylitol Chewing Gum on Salivary Streptococcus mutans and Biofilm Levels in 8- to 12-Year-Old Children. Int J Clin Pediatr Dent 2016;9(4):313-319.

Metabolic Engineering and Comparative Performance Studies of Synechocystis sp. PCC 6803 Strains for Effective Utilization of Xylose.

Wood sugars such as xylose can be used as an inexpensive carbon source for biotechnological applications. The model cyanobacterium Synechocystis sp. PCC 6803 lacks the ability to catabolize wood sugars as an energy source. Here, we generated four Synechocystis strains that heterologously expressed XylAB enzymes, which mediate xylose catabolism, either in combination with or without one of three xylose transporters, namely XylE, GalP, or Glf. Except for glf, which is derived from the bacterium Zymomonas mobilis ZM4, the heterologous genes were sourced from Escherichia coli K-12. All of the recombinant strains were able to utilize xylose in the absence of catabolite repression. When xylose was the lone source of organic carbon, strains possessing the XylE and Glf transporters were most efficient in terms of dry biomass production and xylose consumption and the strain lacking a heterologous transporter was the least efficient. However, in the presence of a xylose-glucose mixed sugar source, the strains exhibited similar levels of growth and xylose consumption. This study demonstrates that various bacterial xylose transporters can boost xylose catabolism in transgenic Synechocystis strains, and paves the way for the sustainable production of bio-compounds and green fuels from lignocellulosic biomass.

Технология ксилита – проблемы производства и пути их решения

Технология ксилита – проблемы производства и пути их решения

Oxidative stress response in canine in vitro liver, kidney and intestinal models with seven potential dietary ingredients.

In vitro cell culture systems are a useful tool to rapidly assess the potential safety or toxicity of chemical constituents of food. Here, we investigated oxidative stress and organ-specific antioxidant responses by 7 potential dietary ingredients using canine in vitro culture of hepatocytes, proximal tubule cells (CPTC), bone marrow-derived mesenchymal stem cells (BMSC) and enterocyte-like cells (ELC). Cellular production of free radical species by denatonium benzoate (DB), epigallocatechin gallate (EPI), eucalyptol (EUC), green tea catechin extract (GTE) and sodium copper chlorophyllin (SCC), tetrahydroisohumulone (TRA) as well as xylitol (XYL) were continuously measured for reactive oxygen/nitrogen species (ROS/RNS) and superoxide (SO) for up to 24h. DB and TRA showed strong prooxidant activities in hepatocytes and to a lesser degree in ELC. DB was a weak prooxidant in BMSC. In contrast DB and TRA were antioxidants in CPTC. EPI was prooxidant in hepatocytes and BMSC but showed prooxidant and antioxidant activity in CPTC. SCC in hepatocytes (12.5mg/mL) and CPTC (0.78mg/mL) showed strong prooxidant and antioxidant activity in a concentration-dependent manner. GTE was effective antioxidant only in ELC. EUC and XYL did not induce ROS/RNS in all 4 cell types. SO production by EPI and TRA increased in hepatocytes but decreased by SCC in hepatocytes and ELC. These results suggest that organ-specific responses to oxidative stress by these potential prooxidant compounds may implicate a mechanism of their toxicities.

Heat transport model for the deliquescence kinetics of crystalline ingredients and mixtures

Deliquescent crystalline solids undergo the first order dissolution process of deliquescence when the environmental relative humidity (RH) exceeds the deliquescence point (RH0). The rate at which deliquescence occurs increases as the RH increases above the RH0 in compressed disks of select deliquescent ingredients; however, a kinetic model for the deliquescence of powdered crystalline food ingredients and blends thereof has not been published. The water vapor sorption rates of commonly used powder food ingredients (citric acid, sodium chloride, sucrose, fructose, sorbitol, and xylitol) and blends were determined using a multi-sample gravimetric moisture sorption analyzer. The water vapor sorption rate was dependent on sample radius, temperature, and sample composition. The heat transport model for the deliquescence of compressed disks was successfully extended to the powder ingredients and blends. Such results enable further understanding of fundamental theories of deliquescence and provide a useful tool in the prediction of water vapor uptake rate during deliquescence in controlled RH chambers.