Aqueous Sugar Solutions Research Articles

Capillary effects of submicron heterogeneities in aqueous solutions of sugars. The additional mechanism of microfluidics

In this paper, we study submicron heterogeneities (SMH) that spontaneously form in aqueous solutions of sugars: glucose, fructose and sucrose, with a concentration of 0.5 mol%. These solutions were passed through glass capillaries with a diameter of about 6 and 13 µm, which led to a decrease in the concentration of SMH without significantly changing their size. For capillaries of smaller diameter, this effect is more pronounced. The decrease in the concentration of SMH is not associated with their mechanical destruction or adsorption on the surface of capillaries. This phenomenon is explained by the destruction of SMH as a result of their interaction with the hydrophilic surface of the capillary. The fundamental differences between the presence of SMH in microfluidic conditions and bulk reservoirs are discussed. This phenomenon should be taken into account in microfluidics.

Matrix effect on the Effectiveness of High Hydrostatic Pressure Treatment on Antibiotic Residues

The use of antibiotics in agriculture and livestock poses health risks to consumers. Treatments such as High Hydrostatic Pressure (HHP) have been shown to reduce antibiotic and pesticide residues in food. This study aims to investigate the matrix effect on the effectiveness of HHP on hydrochloride tetracycline (HTC) and sulfathiazole (STZ) residues in spiked food matrices. The effect of viscosity, as well as carbohydrate, protein, and fat content on the effectiveness of HHP on antibiotic residues, was investigated. The studied matrices were full-fat and fat-free bovine milk and model food systems consisting of aqueous solutions of sugars, aqueous solutions of proteins, and oil in water emulsions. Model food systems were also used to study the viscosity effect. These systems consisted of aqueous solutions of honey, aqueous solutions of apple puree, and aqueous solutions of glycerol. The HHP processing (580 MPa, 6 min, 25 °C) took place under industrial conditions. For both antibiotics, the concentration of sugars and proteins was found to affect the effectiveness of treatment. The concentration of oils affected treatment efficacy only for HTC. Reduction of antibiotics by HHP was also affected by the type of carbohydrate and the viscosity. In conclusion, the composition and the viscosity of the food matrix exert a variable effect on the studied antibiotic residues reduction by HHP indicating different underlying mechanisms of the interactions between food constituents and antibiotics under the same process conditions.

Efficient synthesis of rare sugars from galactose in hot compressed water using eggshells as an environmentally friendly catalyst

Aqueous galactose solutions containing eggshell was heated at 120 °C to produce calcium supplements containing rare sugars. Galactose was isomerized to rare sugars with improving rare sugar yields compared to those without eggshell. Organic acids were also formed as byproducts during the reaction. These acids were neutralized by dissolving eggshells with increasing the calcium ion concentration in the solution.When eggshell components (calcium carbonate, magnesium carbonate, or calcium phosphate) were used for the treatment, rare sugars were also formed. Especially, addition of magnesium carbonate improved rare sugar yield, but byproduct formation became more pronounced.Eggshells used in the treatment were used for repeated treatments. When eggshells were used three times, rare sugar yield changed only slightly but the selectivity of rare sugars improved significantly. By these processes, we obtained an aqueous solution of rare sugars containing calcium ion at 295 mg/L, which has potential as ingredients for dietary supplements.

Dispersed, optical and concentration characteristics of submicron heterogeneities in aqueous solutions of sugars

In this work, a multilateral analysis of submicron heterogeneities (SMH) spontaneously formed in aqueous solutions of sugars - glucose, fructose and sucrose - was carried out at 25 °C using laser scattering methods. The hydrodynamic diameters of SMH in 0.5 mol% solutions are 100–150 nm and vary slightly over a wide range of concentrations. However, the geometric diameters of SMH turn out to be much larger – 150–250 nm. This observation assumes that SMH are rather loose objects. The absence of depolarization of scattered radiation shows that the shape of MH is close to spherical.A new approach based on the methods of dynamic and multi-angle static light scattering using the Mie theory has been developed, which allows determining the refractive index of SMH. In 0.5 mol% solutions of sugars, the refractive index of SMH differs from the surrounding solution by no more than 0.005 for glucose and fructose and no more than 0.01 for sucrose. This corresponds to a 1.8-fold higher concentration of sugars in SMH compared to the average concentration in solution. Although SMH in sugar solutions are practically invisible due to the very small contrast, their numerical concentration is quite large, ∼1011–1012 ml−1, and they occupy a ∼0.1–1 % volume fraction of the solution. Dispersed and optical characteristics of SMH depend on the type and concentration of sugar.

Further functionality targeting the food industry is added to versatile ion-exchange engineering tool

Rolled out more than ten years ago LewaPlus is an intuitive and comprehensive tool that helps engineers plan and design industrial water treatment facilities that use ion exchange and membrane systems. Lanxess AG, the company behind the software, has now added further functionality that targets applications in the food industry. This latest update follows the addition of a module to the software, a year earlier, that covers the industrial treatment of aqueous sugar solutions. Here we look at what the new function does and recap briefly other capabilities that have been added recently.

Glassy dynamics of water in TIP4P/Ice aqueous solutions of trehalose in comparison with the bulk phase.

We perform molecular dynamics simulations of TIP4P/Ice water in solution with trehalose for 3.65 and 18.57 wt. % concentrations and of bulk TIP4P/Ice water at ambient pressure, to characterize the structure and dynamics of water in a sugar aqueous solution in the supercooled region. We find here that TIP4P/Ice water in solution with trehalose molecules follows the Mode Coupling Theory and undergoes a fragile to strong transition up to the highest concentration investigated, similar to the bulk. Moreover, we perform a Mode Coupling Theory test, showing that the Time Temperature Superposition principle holds for both bulk TIP4P/Ice water and for TIP4P/Ice water in the solutions and we calculate the exponents of the theory. The direct comparison of the dynamical results for bulk water and water in the solutions shows upon cooling along the isobar a fastening of water dynamics for lower temperatures, T < 240K. We found that the counter-intuitive behavior for the low temperature solutions can be explained with the diffusion anomaly of water leading us to the conclusion that the fastening observed below T = 240K in water dynamics is only fictitious, due to the fact that the density of water molecules in the solutions is higher than the density of the bulk at the same temperature and pressure. This result should be taken into account in experimental investigations which are often carried out at constant pressure.

Study of Stable Stratification in HiRJET Facility With Direct Numerical Simulation

Stable density stratification in a large enclosure could significantly hamper the effectiveness of natural convection cooling in pool-type liquid metal or gas-cooled advanced reactors. In addition, accurate prediction of stratified front behavior remains to be a challenging task for turbulence modeling. With the rapid growth of high-performance-computing capabilities in recent years, conducting high-fidelity simulations for a large-timescale transient has become more affordable and hence a valuable data source to support turbulence modeling as well as to gain further physical insights. In this work, direct numerical simulation is performed at experiment-consistent conditions to simulate the density stratification transient High-Resolution Jet (HiRJET) facility. Specifically, we focus on the case where an injected aqueous sugar solution has 1.5% density higher than that in the enclosure. In the early stage of the transient, the impingement of the denser jet to the bottom surface of the enclosure promoted turbulent mixing locally. This rendered the establishment of the mixture layer, formation and swift upward propagation of the stratified front, and elevation with (locally) the highest vertical concentration gradient. As the front rose, the diminishing turbulent mass flux slowed down the propagation, and a larger vertical concentration gradient was established. In this stage, both the velocity and the concentration scalar showed large-timescale fluctuation behavior around the stratified front. For the concentration time signal, the characteristic frequency in the power spectral density was found to agree well with the Brunt-Väisällä frequency. The preliminary validation endeavor showed that the stratified front location and the corresponding concentration gradient magnitude in the simulation agreed well with the experiment data. Further validation will mainly revolve around benchmarking against high-resolution density measurement and high-order flow statistics.

Multi-Resolution 3D Optical Mapping of Immune Cell Infiltrates in Mouse Asthmatic Lung.

Asthma is a chronic inflammatory airway disease driven by various infiltrating immune cell types into the lung. Optical microscopy has been used to study immune infiltrates in the asthmatic lungs. Confocal laser scanning microscopy (CLSM) identifies the phenotypes and locations of individual immune cells in lung tissue sections by employing high-magnification objectives and multiplex immunofluorescence staining. In contrast, light-sheet fluorescence microscopy (LSFM) can visualize the macroscopic and mesoscopic architecture of whole-mount lung tissues in three dimensions (3D) by adopting an optical tissue clearing method. Despite each microscopy method producing image data with unique resolution from a tissue sample, CLSM and LSFM have not been applied together due to the difference in the tissue preparation procedures. Here we introduce a new approach combining LSFM and CLSM into a sequential imaging pipeline. We built a new optical tissue clearing workflow in which the immersion clearing agent can be switched from an organic solvent to an aqueous sugar solution for sequential 3D LSFM and CLSM of mouse lungs. This sequential combination microscopy offered quantitative 3D spatial analyses of the distribution of immune infiltrates in the same mouse asthmatic lung tissue at the organ, tissue, and cell level. These results show that our method facilitates multi-resolution 3D fluorescence microscopy as a new imaging approach providing comprehensive spatial information for a better understanding of inflammatory lung diseases. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Natural deep eutectic solvents as a green extraction of polyphenols from spent coffee ground with enhanced bioactivities.

Conventional extraction techniques are usually based on highly pollutant and/or flammable organic solvents. Therefore, alternative environmentally friendly extraction methods are of particular interest for the recovery of bioactive compounds for their application as food ingredients and/or nutraceuticals. Natural deep eutectic solvents (NADES) are a green and nontoxic attractive alternative to hydroalcoholic extraction. NADES media primarily depends on the intermolecular interactions (hydrogen bonding) among their components to form a eutectic mixture with a much lower final melting point than its individual components. Examples of natural deep eutectic NADES solvents include aqueous solutions (25%-50% water) of choline chloride, sugars, and polyols. This study aimed to investigate the application of two NADES, namely, betaine:triethylene glycol (Bet : TEG) and choline chloride:1,2-propanediol (Chol : Prop), as sustainable green solvents for the extraction of polyphenols from spent coffee ground (SCG), a by-product of coffee processing. In particular, the extraction yield and selectivity were evaluated and compared with conventional green extractions (hot water and a hydroalcoholic solution). In addition, the effect of NADES on the antioxidant and antimicrobial activity of the extracts was investigated. The main outcomes were as follows: (i) NADES were as effective as other conventional green solvents in the extraction of polyphenols with the added advantage of operating at milder temperature conditions, without flammable solvents and with sustainable and natural compounds; (ii) the antimicrobial activity of the NADES extracts was 10 times higher than that of the ethanolic and aqueous extracts. Given the low toxicity of NADES, they could be used as formulation aid for food ingredients.

APPLICATION OF SPECTROSCOPY IN ANALYSIS OF SOME FLORAL HONEY SAMPLES COLLECTED FROM FOUR SOUTH ROMANIAN COUNTIES IN 2021

Honey is a concentrated aqueous solution of sugars, especially glucose and fructose, and minor amounts of dextrin, enzymes, volatile oils, organic acids, ethers, and minerals. Honey samples vary in quality according to various factors, such as climate diversity, geographical characteristics, floral supply period, and packaging and storage conditions, which can compromise the quality of the hive's final product. The assessment of honey quality is a major concern that has gained interest internationally because honey has always been subjected to various fraudulent practices which become more sophisticated in the present day. Consumers, beekeepers, and regulatory bodies are interested to have reliable analytical tools and information to allow the detection of adulterated honey. The UV-VIS spectroscopy and FTIR spectroscopy techniques are two analytical methods used to analyze the honey quality nowadays, with hydroxymethylfurfural being used as a standard for testing honey's freshness. The present study was conducted to assess the quality of some floral honey samples (rapeseed, acacia, and polyfloral honey) produced in Argeș, Călărași, Giurgiu, and Teleorman counties from the south of Romania. Differences between honey botanical and geographical origins were analyzed and highlighted with One-way ANOVA (p˂0.05), followed by Duncan`s Multiple Range Test. Our results indicated that honey is a valuable source of bioactive compounds.

The universal behavior of viscosity in supersaturated aqueous sugar solutions and the cryopreservation implications

The universal behavior of viscosity in supersaturated aqueous sugar solutions and the cryopreservation implications

Calculation of water activity in electrolytic solutions using the Electrolattice and Q-Electrolattice equations of state

Water activity directly influences the deterioration, texture, pigmentation, and preservation of nutrients in food. This property quantifies the availability of water for the enzymatic, chemical, or microbiological activity that defines the shelf life of food. In this way, the food industry needs to measure, predict, and control this property. In this context, the present work aims to evaluate the performance of the Electrolattice and Q-Electrolattice equations of state in predicting and correlating the water activity of solutions containing electrolytes. Parameters available in the literature were used to compare the performance of the Electrolattice and Q-Electrolattice equations in predicting the water activity (in binary, ternary, and quaternary solutions of salts). The Q-Electrolattice model presented better performance than the Electrolattice equation, with a relative mean deviation (RMD) of 1.95%, 0.14%, and 0.06% for binary, ternary, and quaternary aqueous electrolytic solutions, respectively. Then, the Q-Electrolattice equation was used to correlate experimental data of systems containing water + NaCl + sugar (fructose, sucrose, glucose, and xylose) at 25°C and water + sugar (fructose, sucrose, glucose, and xylose) at 35°C in aqueous solutions of salts and sugar. The general weighted average of the RMD% was equal to 0.29%. Finally, the procedure was validated with solutions containing water, NaCl, and sugar (fructose, sucrose, glucose, and xylose) at 35°C, a condition that was not used in the parameter fitting process. The overall weighted average of the RMD for predicting the water activity of water + NaCl + sugar solutions at 35°C using the Q-Electrolattice equation was 0.57%, thus validating the parameters estimated in this work. The results obtained in this study showed the feasibility of using the Q-Electrolattice equation to predict water activity in aqueous solutions of salts and sugars used as a basis for the osmotic drying of food.

Sugar acid production on gold nanoparticles in slurry reactor: Kinetics, solubility and modelling

Sugar acids obtained by oxidation of sugars are very valuable molecules which are used as chelating agents, binders as well as ingredients in pharmaceuticals. Arabinonic acid was prepared by oxidation of arabinose on gold nanoparticles deposited on an aluminium oxide carrier. A systematic reaction kinetic study was conducted to reveal the influence of oxygen partial pressure and pH on reaction rate and product selectivity. Experiments were carried out in a laboratory-scale semi-batch reactor which was operated at 70 °C and oxygen partial pressures 0.125–1.0 atm. The pH of the aqueous sugar solution was 6–8. Oxygen was continuously flowing through the semibatch slurry reactor and the pH was kept constant by adding NaOH during the experiments. The oxygen solubility in the reaction mixture was determined in separate experiments. A reaction mechanism was proposed for the formation of arabinonic acid (main product) and arabinolactone (intermediate by-product). The surface reaction of competitively adsorbed arabinose and oxygen was assumed to be rate determining for the arabinose consumption. For the formation of arabinonic acid from arabinolactone, the rate determining step was presumed to be the reaction between arabinolactone and sodium hydroxide. The reactor was described with the perfect backmixing model and the component mass balances were solved numerically during the estimation of kinetic parameters by nonlinear regression analysis. The kinetic model gives new insights in the reaction mechanism and described the experimental data very well. The model has potential for application in the oxidation of other monomeric sugars, too.

TILTED FIBER BRAGG GRATING SENSORS FOR REFRACTIVE INDEX MEASUREMENTS OF LIQUID SOLUTIONS

This publication presents the basic assumptions about the light guiding mechanisms in tilted fiber Bragg gratings, transmission spectra of the fiber with such structures and their sensor properties related to the occurrence of the so-called cladding modes. The light in the form of modes coupled to the optical fiber cladding causes their spectral properties to depend on the difference in the refractive indices of the surrounding medium and the fiber cladding. With the introduction of a small inclination angle of the diffraction fringes forming the Bragg grating, the cladding modes show sensitivity to changes in the refractive index of the environment of aqueous solutions, which makes the spectrum of their applications broad. This publication presents changes in the spectra of selected modes measured for solutions with a specific refractive index, shift sensitivity, and changes in the mode transmission coefficient and processing characteristics at a selected concentration range of solutions. Experimental results show that high order cladding modes respond both by shifting the central wavelength as well as by changing the transmission minimum. In selected ranges, these parameters show a linear characteristic as a function of changes in the concentration of the cane sugar aqueous solution. In the case of TFBG with a tilt angle of 8 °, the sensitivity of wavelength changes is 0.012nm / RIU for solutions with concentrations ranging from 0% to 10% by weight.

Thermodynamic study of the solubility of Guanine and Uracil in deferent aqueous sugar solution

AbstractWe investigate the solubility of guanine and uracil, two nucleic acid bases xylose, glucose, and sucrose solutions in aqueous, It was discovered Guanine solubility rises in lockstep with glucose and sucrose concentrations, However, this is not the case for the other reagents. Guanine solubility increases below 1.5M reagent, and it follows this pattern: ribose(R)

Unwelcome guests at farms breeding the black soldier fly,Hermetia illucens (L.) (Diptera Stratiomyidae)

Livestock farms represent a source of attraction for other species, which find food resources on the animals themselves, in the food supplied to them, in their manure, etc. Insect farms too can suffer infestation by different organisms living on substrates or behaving as parasites and/or predators. Breeding of the black soldier fly (BSF),Hermetia illucens (L.) requires organic materials which are attractive for other arthropods (commensals, mycetophages, scavengers, etc.). During recent years, the breeding system adopted at the Di.Pro.Ve.S. of the Università Cattolica del Sacro Cuore, Piacenza (Italy), has suffered the presence of the following ‘pests’:Megaselia scalaris (Loew) (Diptera Phoridae),Muscina stabulans (Fallén) (Diptera Muscidae),Monomorium pharaonis (L.) (Hymenoptera Formicidae) andCaloglyphus berlesei (Michael) (Astigmata Acaridae). The use of fermented fruit, vegetables or of an artificial diet to induce egg laying proved to be attractive for small flies such asM. scalaris. This species also takes advantage of the aqueous sugar solution used to feed BSF adults. Infestations byM. scalaris are worrying because its larvae can compete efficiently with those of the BSF in substrate colonisation. Likewise,M. stabulans can be attracted by the substrates, even though this species has not shown the same levels of high competitiveness as the previously mentioned species.M. pharaonis was observed to prey on eggs and newborn BSF larvae. Lastly, infestations by the miteC. berlesei were detected when conditions for the larval development of the BSF were not optimal. This species could also be harmful for the workers involved in the breeding. The establishment of insect and mite populations inside BSF rearing boxes suggests that a careful analysis should be made based on the location of the breeding facility and a series of measures should of course be adopted when this kind of structure and activities are designed and realised.

Terahertz Generation by Optical Rectification in Sugar Crystal

We report on THz pulse generation through optical rectification of femtosecond laser pulses in sugar crystals. The sugar crystals were grown from an aqueous solution of caster cane sugar bought in a local grocery. Sugar exhibits rather good nonlinear coefficients ( $d_{23}\simeq 56$ pm/V), but the optical-THz conversion efficiency remains quite weak because of the lack of phase-matching, when pumped by a laser beam of 0.8-μm central wavelength. Nevertheless, sugar availability at a low price makes it a relevant material for trial experiments.

Közeli-infravörös spektroszkópia: gyors és hatékony eszköz a fruktóztartalom mérésére

Since high fructose intake was found to be associated with increased health risks, it is important to raise awareness towards the amount of this widely used sugar within foods and beverages. The rapid and accurate detection and quantification of sugar types is not an easy task using conventional laboratory technologies. Near-infrared (NIR) spectroscopy has been proven to be a useful tool in this regard, and the present study highlights the applicability of this rapid correlative analytical technology in the measurement of fructose concentration against that of other sugars in aqueous solutions of sweeteners. The presented NIR calibrations are accurate for the relative measure of °Brix (R2 = 0.84), and the direct measurement of the individual sugars (R2 &gt; 0.90) even in solutions with multiple sugars.

Raman Optical Activity of Glucose and Sorbose in Extended Wavenumber Range.

Raman optical activity (ROA) is pursued as a promising method for structural analyses of sugars in aqueous solutions. In the present study, experimental Raman and ROA spectra of glucose and sorbose obtained in an extended range (50-4000 cm-1 ) are interpreted using molecular dynamics and density functional theory, with the emphasis on CH stretching modes. A reasonable theoretical basis for spectral interpretation was obtained already at the harmonic level. Anharmonic corrections led to minor shifts of band positions (up to 25 cm-1 ) below 2000 cm-1 , while the CH stretching bands shifted more, by ∼180 cm-1 , and better reproduced the experiment. However, the anharmonicities could be included on a relatively low approximation level only, and they did not always improve the harmonic band shapes. The dependence on the structure and conformation shows that the CH stretching ROA spectral pattern is a sensitive marker useful in saccharide structure studies.

Shape effect on non-covalent dimer stability using classic scaled particle theory

The shape of two non-covalent dimers formed by different variants of the B1 domain of protein G plays an important role for their stability in water and aqueous solutions [Proc. Natl. Acad. Sci. U.S.A. 115 (2018) 10965]. I demonstrate how much the stabilization afforded by the decrease in solvent-excluded volume upon association depends on the shape of the dimers in water and aqueous sugar solutions, using classic scaled particle theory. There is a strong dependence upon the decrease in water accessible surface area associated with dimer formation, whose general significance deserves attention.