High-temperature Hydrolysis Research Articles

Preparation of high V-type relative crystallinity dextrin from V-type granular starch via high-temperature acid-ethanol hydrolysis

High V-type relative crystallinity (VRC) dextrin (HVD) was prepared by high-temperature acid-ethanol hydrolysis (HTAEH) of V-type granular starch (VGS). The influence factors including acid concentration, acidolysis temperature and acidolysis duration on HVD production were investigated along with the formation mechanism. HVD with the highest VRC (45.15%) was prepared in 60% (v/v) ethanol at an HCl concentration of 2.0% (w/w), an acidolysis temperature of 95 °C and an acidolysis duration of 30 min. Increasing VRC during the first stage of HTAEH indicated that the V-type crystalline region of VGS was resistant to acid hydrolysis. The molecular weight of VGS was significantly decreased after 10 min∼30 min of HTAEH but remained relatively constant thereafter. The increase in VRC of HVD was due to acid hydrolysis of amylose (AM), and degraded AM with a peak degree of polymerisation of 107 was more easily to complex with ethanol.

Effect of total solids content on anaerobic digestion of waste activated sludge enhanced by high-temperature thermal hydrolysis

Total solids (TS) content may provide a regulatory strategy for optimizing anaerobic digestion enhanced by high-temperature thermal hydrolysis, but the role of TS content is not yet clear. In this study, the effect of TS content on the high-temperature thermal hydrolysis and anaerobic digestion of sludge and its mechanism were investigated. The results showed that increasing the TS content from 2% to 8% increased the sludge solubility and methane production potential, reaching peak values of 26.6% and 336 ± 6 mL/g volatile solids (VS), respectively. With a further increase in TS content to 12%, the strong Maillard reaction increased the aromaticity and structural stability of extracellular polymer substances, decreasing sludge solubility to 18.6%. Furthermore, the decrease in sludge biodegradability and the formation of inhibitory by-products resulted in a reduction in methane production to 272 ± 4 mL/g VS. This article provides a new perspective to understand the role of TS content in the thermal hydrolysis of sludge and a novel approach to regulate the Maillard reaction.

ИЗУЧЕНИЕ ПОТЕНЦИАЛА ЛИЧИНКИ HERMETIA ILLUCENS И ЕЕ ГИДРОЛИЗАТОВ ДЛЯ ИСПОЛЬЗОВАНИЯ В КАЧЕСТВЕ ИСТОЧНИКА БЕЛКА И ЖИРА В АКВАБИОТЕХНОЛОГИИ

The problem of a high-quality source of protein and fat is relevant for the development of aquaculture. An alternative substitute for animal components is the larva of the black soldier fly Hermetia illucens. Due to the presence of chitin, the components of the larvae are not completely absorbed by fish. The purpose of the study was to assess the nutritional value of proteins and lipids of the Hermetia illucens larva after high-temperature hydrolysis. As a result, water-soluble and water-insoluble protein supplements and a fat supplement were obtained from the larva. The chemical composition of raw materials and additives, the amino acid composition of protein additives and their balance for salmon as well as fatty acid composition of the lipid supplement and the ratio of the main groups of fatty acids have been established. An increased content of calcium, phosphorus, iron, magnesium, zinc, and potassium in the water-insoluble additive is shown. A decrease in the chitin content in protein-containing supplements has been established. It is recommended to use additives obtained from the larvae in the composition of fish feed in aquaculture.

Characterization of a recombinant endo-β-1,3-glucanase from Alkalihalobacillus Clausii KSM-K16 and its application in the production of curdlan oligosaccharides

Curdlan polysaccharides are hydrolyzed to provide bioactive β-1,3-gluco-oligosaccharides, which are finding increasingly used in biomedical applications. Alkalihalobacillus clausii KSM-K16 (AC-GA) is an alkalophilic bacterium endo-β-1,3-glucanase. It has a predicted molecular weight of 30.09 kDa and is made up of 257 amino acids. It was expressed in Escherichia coli and purified to homogeneity. This study analyses the properties of AC-GA, product distribution, and structural aspects of AC-GA that may be relevant to sugar molecule production. The optimum reaction condition of the enzyme is 70 °C, pH 7.0, and its catalytic activity increased by Mn2+. Meanwhile, Zn2+ and Cu2+ inhibited AC-GA activity. It is worth mentioning that the isolated enzyme demonstrated remarkable stability at both high temperature, and neutral environments, when curdlan was utilized as the substrate, the enzyme activity reached 1008.98 U/mg. Hydrolysates of curdlan polysaccharide were β-1,3-gluco-oligosaccharides with polymerization (DP) degrees ranging from 1 to 5. This implies that the AC-GA active site might identify up to five glucose units. High concentration of AC-GA mostly creates glucotriose (DP3), whilst low concentration of AC-GA produces oligosaccharides with varying DP (primarily DP1, DP3, and DP4). Additionally, the catalytic triad (Glu134, Asp136, and Glu139) plays a decisive role in the activity of AC-GA, and structural analysis revealed that Trp129, Trp118, Trp114 and Trp 232 are involved in hydrophobic stacking interactions. This study provides a theoretical basis for the acquisition of curdlan oligosaccharides with higher application value under high-temperature hydrolysis.

Preparation and performance evaluation of hydrogen-producing catalysts for diesel reforming

Ru/Al2O3 catalyst was prepared by standard impregnation method. The catalytic reforming performance of Ru/Al2O3 and commercial high nickel/low nickel catalysts on commercial No.0 diesel oil was studied. The regeneration method of carbon-deposited catalyst was also discussed. The results show that commercial low nickel catalyst has poor catalytic activity and stability for diesel, and increasing the water-carbon ratio can slightly improve the conversion rate of diesel. Increasing the reforming reaction temperature and adding methanol additives can effectively improve the catalytic activity of commercial high nickel catalysts. Ru/Al2O3 is a potential catalyst for diesel reforming, reducing the reforming reaction temperature can effectively prevent the catalyst from high temperature hydrolysis deactivation. Hydrogen peroxide has a good regeneration effect on Ru/Al2O3 catalyst.

A colorimetric detection of Hg2+ based on gold nanoparticles synthesized oxidized N-methylpyrrolidone as a reducing agent

In this study, a gold nanoparticles colorimetric probe (AuNPs) with direct response to mercury ions (Hg2+) were developed using treated N-methylpyrrolidone (NMP) and chloroauric acid (HAuCl4) as precursors. NMP showed good reducibility after high temperature hydrolysis and could be used as reducing and stabilizing agent to synthesize AuNPs. The prepared AuNPs have obvious characteristic absorption peaks and appear wine-red. At the same time, it was found that the presence of Hg2+ can cause the aggregation of AuNPs, increased the absorbance at 700 nm, and changed the color of the solution into blue-gray. This method is capable of sensitive and specific determination of Hg2+ ranging from 1 to 30 μM, with the limit of detection (LOD) at 0.3 μM. The method showed good specificity for the determination of Hg2+ and has the potential to be applied to Hg2+ detection in sewage samples in the environment.

Antitumor Activity of Carboxymethyl Pachymaran with Different Molecular Weights Based on Immunomodulatory and Gut Microbiota.

Carboxymethyl pachymaran (CMP) was treated via high-temperature and cellulase hydrolysis to obtain HTCMP, HTEC-24, and HTEC-48. The chemical structure and in vivo antitumor activities of the four types of CMPs were investigated. Compared with CMP (787.9 kDa), the molecular weights of HTCMP, HTEC-24, and HTEC-48 were decreased to 429.8, 129.9, and 68.6 kDa, respectively. The viscosities and particle sizes of the CMPs could also decrease with the decline in the molecular weights. All the CMPs showed antitumor abilities, but HTEC-24 exhibited the best activity. In the animal study, when curing the spleen and thymus, CMPs displayed immunomodulatory effects by increasing the secretion of IFN-γ and IL2 in mice. The CMPs also exerted an antitumor ability by regulating the gut microbiota in tumor-bearing mice. Our results established a foundation to develop an antitumor drug with CMP.

Improved secretory expression and characterization of thermostable xylanase and β-xylosidase from Pseudothermotoga thermarum and their application in synergistic degradation of lignocellulose.

Xylanase and β-xylosidase are the key enzymes for hemicellulose hydrolysis. To further improve hydrolysis efficacy, high temperature hydrolysis with thermostable hemicellulases showed promise. In this study, thermostable xylanase (Xyn) and β-xylosidase (XynB) genes from Pseudothermotoga thermarum were cloned and secretory expressed in Bacillu subtilis. Compared with Escherichia coli expression host, B. subtilis resulted in a 1.5 time increase of enzymatic activity for both recombinant enzymes. The optimal temperature and pH were 95°C and 6.5 for Xyn, and 95°C and 6.0 for XynB. Thermostability of both recombinant enzymes was observed between the temperature range of 75-85°C. Molecular docking analysis through AutoDock showed the involvement of Glu525, Asn526, Trp774 and Arg784 in Xyn-ligand interaction, and Val237, Lys238, Val761 and Asn76 in XynB-ligand interaction, respectively. The recombinant Xyn and XynB exhibited synergistic hydrolysis of beechwood xylan and pretreated lignocellulose, where Xyn and XynB pre-hydrolysis achieved a better improvement of pretreated lignocellulose hydrolysis by commercial cellulase. The observed stability of the enzymes at high temperature and the synergistic effect on lignocellulosic substrates suggested possible application of these enzymes in the field of saccharification process.

Thermal Analysis and Phase Equilibria of the Molten System Na3AlF6-NdF3-Nd2O3

Phase diagrams of the systems Na3AlF6-NdF3 and (Na3AlF6-NdF3)eut-Nd2O3 were experimentally determined by thermal analysis up to 60 mol.% NdF3 and 45 mol.% Nd2O3, respectively. The Na3AlF6-NdF3 system was found to be a simple eutectic system with the eutectic point with the following approximate coordinates: 49 mol.% NdF3 and 905°C. This eutectic composition was then used for the thermal analysis of the (Na3AlF6-NdF3)eut-Nd2O3 system. The coordinates of the eutectic point of the (Na3AlF6-NdF3)eut-Nd2O3 system were found to be approximately 46 mol.% Nd2O3 and 733°C. After the thermal analysis, the x-ray diffraction analysis of the solidified samples of both systems was performed. The XRD analysis of the Na3AlF6-NdF3 system has shown the formation of two new compounds; NaNdF4 and NdOF. The formation of NdOF is probably the product of the high-temperature hydrolysis between the moisture in the atmosphere and NdF3. The XRD analysis of the solidified samples of the (Na3AlF6-NdF3)eut-Nd2O3 system has shown the formation of the following new compounds: NaNdF4, NdOF, NdAlO3, and NaF.

Efficient production of chito-oligosaccharides through microwave-assisted hydrothermal and low-acid-mediated degradation and deacetylation of chitin

The conventional method for producing chitin oligosaccharides involves high-temperature hydrolysis in high-concentration acid. In this study, we present an alternative method using microwave-assisted hydrothermal and diluted acid (0.12 mol/L) hydrolysis. After batched reactions, the liquefaction rate of chitin can reach almost 50%, and the sugar product yield is about 27%. Furthermore, this method leads to the reduction of the average particle size of chitin by approximately 70%, a decrease in the degree of acetylation by about 35%, partial destruction of the intermolecular hydrogen bond network, and the breaking of glycosidic bonds. These changes result in the exposure of more hydroxyl groups and enzyme binding sites, which may facilitate a subsequent enzymatic treatment. The method is a feasible alternative to obtain chitin oligosaccharides with a low environmental impact and operating cost.

Конверсия пшеничных отрубей в целевые продукты биосинтеза

A more efficient bioconversion of renewable plant resources is a priority in modern biotechnology. An important aspect of the processing and pretreatment of cellulose raw materials is to obtain a high content of reducing substances in the final product. The present research objective was to determine the optimal conditions for the chemical transformation of plant polymers to obtain biologically valuable substances. The research results will reduce the final cost of biotechnological production.
 This research featured wheat bran polymers treated with sulfuric acid and relied on a set of standard research methods. The degree of polymer conversion was tested on native and mechanically activated wheat bran fractions of 600, 200, and 100 microns. The kinetics of the high-temperature chemical hydrolysis was as follows: temperature – 120–130°C, sulfuric acid concentration – 0.6–0.9%, treatment time – 30–60 min, hydromodule – 1:8;9;10. The quantitative and qualitative composition of mono- and disaccharides of hydrolysates was determined using the high performance liquid chromatography method. 
 The composition of wheat bran showed a low content of lignin (7.55%) and a high content of pentosans (17.9%). The highest content of reducing substances in hydrolysates was 640 mg/g bran. The optimal technological conditions with the highest content of reducing substances were as follows: hydromodulus – 1:10, temperature – 120°C, treatment time – 45 min, and sulfuric acid concentration – 0.9%. The greatest change in the content of mono- and disaccharides of hydrolysates belonged to pentoses: 78.2 mg/g of bran (in terms of xylose). The amount of easily hydrolysable carbohydrates and wheat bran fiber decreased by 80 and 19%, respectively.
 This research revealed the optimal parameters for the chemical hydrolysis of wheat bran to obtain biologically valuable carbohydrates. This area of research can be of practical use for producers of biofuels, chemicals, and food additives.

Electrodeposited Ni/C-SnO2 composite electrode materials for hydrogen evolution reaction in alkaline electrolyte

The high performance Ni/C-SnO2 composite electrodes were successfully prepared for hydrogen evolution reaction (HER) in alkaline media by an easy and low cost composite electrolytic deposition method. The Ni/C-SnO2 composite coating was physically examined by using various techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive analysis of X-ray (EDX). The XRD and EDX results showed that C-SnO2 particles prepared by high temperature hydrolysis method were successfully incorporated in Ni coatings. The preferred orientation of Ni particle in composited coatings had been altered to (111) crystal plane which was more benefit for HER. The SEM and XRD results indicated that the addition of C-SnO2 particles refined Ni crystallization in composite coatings. The catalytic activity and stability of the composite coatings for hydrogen evolution reaction were examined by steady-state polarization, Tafel plots, electrochemical impedance spectroscopy (EIS) and chronopotentiometry technique. Compared to Ni coating, the Ni/C-SnO2 composite coatings exhibited higher hydrogen evolution performance. The abundant OHads on C-SnO2 surface accelerated the water molecular decomposition and Hads formation which determined the rate of HER (Volmer step). The carbon in C-SnO2 improved the conductivity of composite electrode, which was also helpful for HER.

Эволюция структурных и точечных дефектов в кварцевом стекле, подвергнутом тонкому отжигу

The silica glass with a high content of OH groups was synthesized by the high-temperature hydrolysis of SiCl4 in a flame of oxyhydrogen torch and subjected to fine annealing. A combination of the photoluminescence and IR reflection spectroscopy was applied to assess the evolution of the ensemble of structural defects in the bulk and surface layer over the course of annealing carried out at 480 ˚C. The marked decrease of the defect concentration was observed in the bulk at all time expositions in the range 2 to 72 hours. However, in a thin surface layer, the decrease of the concentration of silanol groups Si-OH formed in the process of synthesis was detected. Decay of these groups results in the silicate network consolidation that led to the forming of the superficial layer characterized by an elevated microhardness.

Использование пептидов шпротного вторичного сырья в производстве соусной продукции

The relevance of the topic is justified by the demand for fish sauce products of increased nutritional value, the underutilization of the biopotential of sprat waste and sea buckthorn growing in the Kaliningrad region. The chemical composition, amino acid composition of proteins of the peptide and protein-mineral additives, made by the method of high-temperature hydrolysis from the heads of smoked sprats, was studied. The high biological activity and digestibility of the peptide sprat additive is shown. Using the method of mathematical planning of the experiment, a mathematical model was obtained that reflects an adequate relationship between the organoleptic assessment of the sauce and the content of the main components. On the basis of this model, the optimal dosages of the peptide additive and rye flour were established, which determine the desired taste, aromatic and structural properties of the sauce. The formulation and technology of four types of original sauce products with the use of sprat peptide additive, rye flour, cream and sea buckthorn oil have been developed. The formulation and technology of four types of original sauce products with the use of sprat peptide additive, rye flour, cream and sea buckthorn oil have been developed. The organoleptic quality indicators of the resulting sauces with and without the addition of sea buckthorn oil have been established. The general chemical composition of sauce products was studied, indicating its balance in terms of the content of proteins, fats and carbohydrates. A high content of carotenoids in sauces with sea buckthorn additives and their functionality in terms of beta-carotene content have been established. The general chemical composition of sauce products was studied, indicating its balance in terms of the content of proteins, fats and carbohydrates. A high content of carotenoids in sauces with sea buckthorn additives and their functionality in terms of beta-carotene content have been established.

Succeeded high-temperature acid hydrolysis of granular maize starch by introducing heat-moisture pre-treatment

Acid hydrolysis is a crucial method for modifying granular starch, but it is often conducted at low temperatures (below 55 °C) for an extended period of time to prevent crystallinity loss. The high-temperature acid hydrolysis (HTAH) behavior of heat-moisture treated (HMT) starch at 69 °C was investigated for the first time. The crystalline structure of starch was enhanced by HMT, confirmed by its rheological, thermal, and infrared Fourier transform spectroscopy results. The amorphous structure of HMT starch was preferentially hydrolyzed with high reactivity, related to a fast hydrolysis stage (4.17 × 10−2 min−1). And the crystalline flakes were separated from starch granules, accompanied by strengthened molecular interactions. HMT starch was transformed from 16.98 μm granules to 158 nm thick and 2.57 μm broad flakes with a 6.40 % increase in crystallinity after 40 min of hydrolysis. For native starch, the HTAH destroyed the crystalline structure due to gelatinization, resulting mainly gelatinous aggregates. These evidenced that the hydrolysis of granular starch was successfully performed at a relatively high temperature by introducing heat-moisture pre-treatment. This study could provide a novel perspective on the combination of increasing temperature and pre-treatment for granular starch hydrolysis intensification design, as well as a strategy for efficiently preparing small-sized crystalline starch, which has promising applications in Pickering emulsion and material filler.

Effects of Iron Powder Addition and Thermal Hydrolysis on Methane Production and the Archaeal Community during the Anaerobic Digestion of Sludge.

The conventional anaerobic digestion of sludge has the disadvantages of long digestion time and low methane production. Pretreatment is often used to mitigate these problems. In this study, three pretreatment methods, namely, the addition of iron powder, high-temperature thermal hydrolysis, and a combination of these methods, were compared for application with conventional continuous anaerobic digestion reactors. The results showed that pretreatment improved methane yield by 18.2–22.9%, compared to the control reactor (conventional anaerobic digestion). Moreover, it was recognized that the archaeal community in the sludge underwent significant changes after pretreatment. Specifically, the addition of iron powder reduced the diversity in the archaeal community, but increased the abundance of hydrogenotrophic methanogens without changing the community composition. Thermal hydrolysis at high temperatures had the reverse effect, as it increased the diversity of the archaeal community but inhibited the growth of acetoclastic methanogens. In the case of the combined pretreatment, the thermal hydrolysis had a dominant influence on the archaeal community. By comparing the changes in functional gene content, it was found that the functional abundance of the archaeal community in the transport and metabolism of carbohydrates, lipids, and amino acids was higher after pretreatment than in the control group.

Preparation and characterization of OH/SiO2-TiO2/PES composite hollow fiber membrane using gas-liquid membrane contactor for CO2/CH4 separation

In this study we used a high-temperature steam-induced hydrolysis method to obtain a fluorinated OH/SiO2-TiO2/polyethersulfone (PES) composite hollow fiber membrane for CO2 capture. The purpose of grafting SiO2 and TiO2 on the surface of PES by hydrolyzing silicon precursors and titanium precursors at high temperature, is to improve the alkali corrosion resistance and hydrophobicity of the PES membrane. The OH/SiO2-TiO2/PES composite hollow fiber membranes prepared by the high-temperature steam-induced hydrolysis method and the graft coating method were measured by SEM, EDS, FTIR, WCA, AFM, XRD and XPS in order to characterize the morphology and structure of the prepared membranes. In the CO2/CH4 separation performance test experiment, the OH/SiO2-TiO2/PES membrane prepared by the high-temperature steam hydrolysis method showed better separation performance than the original PES membrane. The effects of absorbent flow rate, absorbent concentration and feed gas flow rate on CO2 flux and CO2/CH4 were selectivity investigated. When the flow rate of the absorbent (DEA) reached 16 L/h, the flow rate of the feed gas (CO2/CH4 = 40 : 60) was 30 ml/min, the concentration of the absorbent was 1 mol/L, The CH4 concentration was 99.88 % and the optimal separation factor was as high as 554.89. In general, the results obtained in this work may provide promising insights into the use of fluorinated OH/SiO2-TiO2/PES composite membranes for carbon capture and CO2/CH4 separation in GLMC application.

ЭФФЕКТИВНОСТЬ КОРМЛЕНИЯ БРОЙЛЕРОВ ПЕРЬЕВОЙ МУКОЙ, ПОЛУЧЕННОЙ МЕТОДОМ КРАТКОВРЕМЕННОГО ГИДРОТЕРМИЧЕСКОГО ВОЗДЕЙСТВИЯ

In the poultry industry, animal flour is often used, which is prepared from a mixture consisting of the remains of bones, soft tissues and feathers. They are rarely processed separately, especially for feathers, which have a very low digestibility. The technology of short-term high-temperature hydrolysis of feathers in a thin layer leads to the destruction of the keratin structure and increases the availability of its amino acids. This processing method achieves 86–88% of protein digestibility. The efficiency of using this feather meal (PM) in feeding makes it possible to reduce the cost of rations and improve zootechnical indicators.

Mössbauer spectroscopy of superparamagnetic Fe3O4 nanoparticles

Spherical, mono-disperse, non-interacting iron oxide (Fe3O4) nanoparticles, synthesized by high-temperature hydrolysis of chelated iron alkoxide complexes, have been studied by Mössbauer spectroscopy. The critical diameter for room temperature superparamagnetism, an important parameter for high frequency biomedical (MRI) and IT applications, was about 11 nm. Particles of diameter 11.9 nm and greater are ferrimagetic and showed magnetic splitting. Particles of diameter 10.6 nm and smaller are superparamagnetic and gave a non-magnetic spectrum at room temperature. The lines narrow as the particle size decreases and the spin relaxation rate increases. For the smallest particles (8.6 nm or less) the room temperature spectra could be resolved into two partially overlapping lines, one from the A-sites and one from the B-sites, the latter being broadened by the nuclear quadrupole interaction. Similar spectra have been previously reported for bulk Fe3O4 above the Curie point. The isomer shifts showed anomalies possibly arising from magnetostrictive atomic displacements. On applying a magnetic field of 20 kG, hyperfine splitting was observed, confirming that the particles are single-domain with large magnetic moments of the order of 104 μB. The in-field spectrum was similar to that of bulk crystals above the Verwey temperature with Fe3+on the A-sites and Fe2.5+ on the B-sites, characteristic of the inverse cubic spinel structure. The lines narrowed as the temperature was decreased until magnetic splitting was observed at temperatures below the blocking temperature TB, where the magnetic fluctuations are blocked. The transition to the magnetic state is smooth, confirming that the particles are mono-disperse. At the lowest temperature (6 K) the spectra resemble those of bulk Fe3O4 with Fe3+on the A-sites and both Fe2+ and Fe3+ on the B-sites corresponding to the local monoclinic distortion, indicating that the nanoparticles have undergone a Verwey transition. The values of TB found are lower than those reported by most other researchers, suggesting that magnetic interactions between our particles are small. The non-stoichiometry parameter, x, defined by the formula Fe3-xO4, was estimated from the relative amounts of Fe3+/ Fe2+ and from isomer shifts to be less than 0.1 in the different samples.

Identifying silica types using viscosity data and principal component analysis

As the most important glass former, silica has a plethora of relevant industrial and commercial applications. Silica glass can be classified into several types depending on the starting materials, production method, content and impurities. Briefly, type I is obtained by melting natural or synthetic quartz in electrical furnaces, presenting alkali and metal impurities (in ppm). Type II is obtained from melting natural or synthetic quartz in hydrogen–oxygen or natural gas flames with few impurities (in ppm) but high concentration of structural water. Type III is obtained from high-temperature hydrolysis of volatile compounds of silicon with low metal impurities and considerable concentrations of structural water and chlorine. Type IV is obtained from high-temperature oxidation of silane with small amounts of metal impurities, almost no structural water but high chlorine content. We analyzed literature data on viscosity, η, for 44 batches over a wide temperature range, from glass transition, Tg, to far beyond the melting point, Tm, for four of five silica types. The viscosity behavior in silica follows the Arrhenius expression: log10η(T)=A+BT, with η in Pa⋅s, T in K, where A and B are constants. However, the Vogel-Fulcher-Tammann-Hesse (VFTH) equation: log10η(T)=A+BT−T0,can also be applied to this system, with T0 → 0 as another constant (in K). For a fixed temperature, a variance of η, covering two orders of magnitude, was observed for types I and II, and about one order for the other two types, mainly due to impurity content and the manufacturing process. Another important observation was that the highest viscosities were found in the purest silicas. Not all samples presented T0 = 0, as expected for Arrhenius viscosity behavior. An analysis considering the Mauro-Yue-Ellison-Gupta-Allan (MYEGA) viscosity equation was also performed. Previous studies of principal component analysis (PCA) considering A, B and T0 allowed the mapping of binary and ternary silicate and borate systems. In brief, PCA is a mathematical technique which rearranges information from datasets and can classify silica types according to their viscosity parameters. The results show that it is possible to map the four silica glass types according to viscosity VFTH and MYEGA parameters taken from experimental data.