Sugar Dissolution Research Articles

On Perceiving Molecular Time: Computational Chemical Simulations and the Moving Image

The perception of time undergoes a radical shift between the human scale and the nanoscale. In an age of rapidly evolving media and scientific technologies, we need to understand how these impact human perception and visual culture. This essay explores computational molecular simulations through the lenses of temporal media theory and moving image practice. Emerging from a creative fellowship with a physical chemistry research group, I focus on two moving image works that depict crystalline structures. One is a nanoscale computational simulation of soot formation and the other is a durational video artwork showing the dissolution of sugar. Computational molecular simulations are shown to produce a feeling of time by smearing an extremely short duration across a longer perceptible duration. This analysis uncovers how the awareness of media as a construct troubles our chronoception (perception of time), while unexpectedly, the screen becomes complicit in scientists’ expert temporal understanding. The videos present vastly different spatial and temporal scales and have different chronoceptive effects: one gives a sense of being within time, the other across time. Ultimately, computational simulations emerge as isomorphic media that have explicit aesthetic properties that connect us to the implicit, abstract energetics of chemical reactivity.

Promoting 3rd grade pupils’ learning of science knowledge through project-based learning in a Finnish primary school

We explored third grade pupils’ (9–10-years, n = 22) learning of various science knowledge while engaged in scientific practices during a designed project-based learning (PBL) module. The topics selected were familiar to pupils, such as the dissolution of sugar and rising of dough with yeast. The study sheds light on the type of knowledge the pupils communicate with while they are involved in scientific practices and creation of digital artefacts. The video recorded data were collected in a Finnish primary school classroom. In total 22 clips (duration of 2–8 minutes) were the primary data. The qualitative content analysis revealed that the pupils engaged in factual, conceptual, procedural, and metacognitive knowledge in PBL collaborative activities. The analyses described pupils’ interactions and actions when they employed these different types of knowledge. In conclusion, PBL modules based on familiar everyday contexts can support primary pupils to learn scientific practices and use versatile types of knowledge.

Evaluación de las isotermas de sorción en snacks con mandioca pregelatinizada

Sorption characteristics are studied for their influence on the storage stability of dehydrated products and their effect on water vapour diffusion. In the present work, the adsorption curves of snacks with and without substitution of wheat flour by dehydrated cassava puree (PDM) were analysed using saturated salt solutions at 10, 30 and 50 ºC. Type III curves were obtained for the samples with PDM and type II for the control sample. Mathematical modelling was then performed using 8 different equations, obtaining the best fits for the Peleg (R2adjust =0.999-0.988), Ferro Fontan (R2adjust =0.998-0.970) and GAB (R2adjust =0.999-0.955) models. The values of the model constants in some cases turned out to be formulation and temperature dependent, and in general do not show a definite trend. This can be seen graphically as crossovers between the curves. This crossover of curves has been attributed to the increased exposure of hydrophilic groups due to increased molecular mobility at high humidity and occurrence of the glass transition in the system and/or endothermic dissolution of sugars.

In vitro digestibility of rare sugar (D‐allulose) added pectin–soy protein gels

SummaryConfectionery gels are known to be high‐caloric products due their high sugar content. Changing their formulations by substituting the sugar with alternative natural sweeteners and functionalising them, the addition of proteins has gained attention. Understanding the rate of digestion of these products is also important for selecting the appropriate formulation. In this study, in vitro gastric digestion behaviour of the gels formulated with D‐allulose, a low‐calorie rare sugar, soy protein isolate (SPI) (1%, 2.5%) and pectin (4%) were examined. Digestion decreased the hardness of the gels (P < 0.05), but, at 2.5% SPI concentration. Moisture content of the samples increased after digestion and presence of SPI induced higher water uptake. At the end of 2 h of digestion, 1% soy protein isolate containing gels had the highest brix values showing that after a certain concentration, soy protein isolate governed the system due to improved soy protein–pectin interaction or due to improved gelation with Maillard reaction. NMR relaxometry experiments further confirmed the changes in the gels with the increase in T2 values. Power law model was fitted for the dissolution behaviour using the oBrix values of the digestion medium. Dissolution of sugar and the contribution of SPI to the gel network were clearly observed in SEM images. Results showed that these gels had the potential to slow down the emptying rate of stomach thus could lead to ‘fullness’ for a longer time.

Formation of structure of disperse systems in non-equilibrium state under conditions of combination of two types of cavitation effects

The description of the existing method for producing invert syrup in stages in a large volume under the conditions of using one type of energy flow is given. The purpose of this work is to develop the principles of transition from macrostatic equilibrium to the development of each microstatic volume of liquid dispersed systems in the process of their production in a non-equilibrium state created by the combination of two types of cavitation effects: hydrodynamic and acoustic effects. The properties of dispersed systems are described and the object of research is invert syrup with the amount of dry 80% and reducing 79-80% substances. Invert syrup with 100% inversion of sucrose to glucose and fructose is widely used in the production of flour confectionery and a number of pastille and marmalade products. The principles of formation of aggregates from sucrose molecules at the stage of sugar dissolution, the formation of voids and the nucleation of gas phase bubbles are established. The conditions for creating a non-equilibrium state of syrup under the conditions of using two types of energy flows, by combining hydrodynamic and acoustic cavitation, are considered. The character of the transformation of the state of bubbles under conditions of changing the flow geometry of gas-liquid systems and the excitation of sound vibrations in them is shown. The mechanism of structure formation of a gas-liquid system under the influence of acoustic vibrations on the structure is described. The character of transformation of highly concentrated gas-liquid systems after the collapse of gas phase bubbles is shown, which was the determining factor in the formation of new types of materials. The practical output of this work was the creation of invert syrup with 100% fructose and glucose content in dry substances. Preparation of an emulsion for flour confectionery products and marmalade based on fresh fruits and vegetables. The effectiveness of combining two types of cavitation exposure opens up the prospect of creating new types of confectionery products with fundamentally new properties, while preserving native vitamins and nutrients.

One-pot chemo-catalytic conversion of glucose to methyl lactate over In/γ-Al2O3 catalyst

The huge demand of lactic acid in widespread applications has significantly impelled the development of cost-effective strategy for the production of lactic acid, in particular its derivative (methyl lactate, MLA) due to the simpler separation and purification process. Herein, in this work, we developed a series of robust but simple In/γ-Al2O3 catalysts with different In loadings. The results indicated that In doping obviously increased the amount of mid-strong acid on the catalyst, which significantly facilitated the selective cleavage of C3-C4 bond in C6 sugar (rate-controlling step), as well as the next esterification reaction. 12-In/γ-Al2O3 catalyst, with the most mid-strong acid sites, exhibited the best catalytic activity for MLA production from renewable sugars in methanol solvent. The addition of only a small amount of water could accelerate sugar dissolution in methanol solvent, and alkali (K2CO3) addition further promoted C3-C4 cleavage, thus yielding more C3 intermediates. When dihydroxyacetone and pyruvaldehyde intermediates were employed as feedstock, as high as 86.0 % and 98.0 % yields of MLA could be obtained, respectively. Even in the case of glucose and fructose as feedstock, MLA yields were up to 49.0 % and 54.2 %, respectively, under the optimized conditions. This work might provide a potential approach for the synthesis of lactic acid and its derivatives with low production cost.

Electrowetting based local sensing of liquid properties using relaxation dynamics of stretched liquid interface

HypothesisMonitoring progression of biochemical processes is required for medical and industrial applications. Spatiotemporal changes in fluid properties can be measured to determine progress of biochemical processes like blood coagulation. Localised electrowetting-on-dielectric (EWOD) actuates a part of droplet contact line, allowing local measurement of fluid properties without inducing bulk fluid motion, which is unlike full droplet oscillation-based techniques. ExperimentsIn this work, narrow electrodes (50–450 μm) were used to actuate a portion of drop interface. Dynamics of interface actuation and relaxation was used to estimate the local visco-elastic properties of the droplet. FindingsFor local interface motion, theory predicts a generic dispersion relation ω=cqn. In agreement with theory, decay time was found to be proportional to viscosity and inversely proportional to surface tension. Interface displacement remained almost constant for different viscosities, but it decreased with increase in surface tension. Capability to measure spatiotemporal dynamics of chemical process was demonstrated for sugar dissolution in a droplet of water. For full droplet oscillation-based techniques, the induced bulk flows adversely affect the monitored process. Localised EWOD reduces bulk flows in the sample. So, this technique was applied to study blood coagulation dynamics, enlightening the future prospect of developing biomedical sensors.

Influence of high-intensity ultrasound application on the kinetics of sugar release from acid suspensions of artichoke (Cynara scolymus) biomass

The study of sugar release kinetics is an essential step prior to developing new technologies for applying in the bioethanol industry. To this end, the kinetics of reducing and total sugar release (extraction/hydrolysis) from artichoke waste were obtained in different conditions to evaluate the solubility of free sugars from raw matter and the hydrolysis of larger chain molecules separately. Thus, experiments of extraction with water (WE), hydrolysis (HY) in acid solutions and a conventional industrial hydrolysis (IHY), which combines dissolution and hydrolysis effects, were carried out. All of the treatments were studied with ultrasound application (US) or with conventional agitation (AG). Compared to AG experiments, US application accelerated the sugar dissolution reducing 50% the time to reach the equilibrium. The decrease in the biomass concentration in the suspensions increased the US effects in HY experiments. In IHY experiments, US was also able to enhance the final yield of sugars achieving relative reducing sugar and total sugar amounts 213% and 175%, significantly higher than AG experiments. The rheological changes in the suspensions during treatments can explain the different magnitude of ultrasound effects. The acoustic field characterization and the measurement of viscosity in the acid suspensions agreed with these results.

Theoretical background the control technology of flour confectionery products and their practical implementation

The development of technologies of flour confectionery products, carried out by the all-Russian research Institute of the confectionery industry, is in the field of knowledge of industrial engineering, which are tools for creating innovative technologies. Innovation, confectionery companies carried out by combining equipment, control, measuring and information systems, by eliminating technical contradictions between the operation and control of technological flow. Theoretical prerequisites for the management of technologies of flour confectionery products were the provisions of the system approach and physico-chemical mechanics. Thus, by determining the criteria and regulation of the rheological properties of confectionery masses provides stabilization of the process and it becomes possible to control the intermediate stages and the flow of technology as a whole for different types of products that have a common principle of the structure of the process. For the purpose of practical realization of theoretical prerequisites of technology management the Institute has developed a complex of technological methods. Obtaining of two-phase systems for each type of raw material provides the possibility of adapting the technology to the use of raw materials with a significant range of quality characteristics. Increasing the amount of "free" water provides a test with a given humidity. The flow of components for kneading dough ensures an increase in the uniformity of the distribution of components. Control of the degree of dissolution of sugar provides products with specified structural and mechanical parameters. The use of a new type of energy supply provides an increase in the number of solid phase particles in the emulsion more than 75 times and intensification of the process. Methods of obtaining semi-finished products on the basis of fruits and vegetables provides the possibility of obtaining semi-finished products from fresh fruits and vegetables according to the technologies developed by the Institute. Also in practical implementation it is necessary to use developments of Institute in which the basic principles of creation of innovative technologies of flour confectionery with the set structure and properties are lit.

Sugar glass fugitive ink loaded with calcium chloride for the rapid casting of alginate scaffold designs

Alginate-based hydrogels are widely used for the development of biomedical scaffolds in regenerative medicine. The use of sugar glass as a sacrificial template for fluidic channels fabrication within alginate scaffolds remains a challenge because of the premature dissolution of sugar by the water contained in the alginate as well as the relatively slow internal gelation rate of the alginate. Here, a new and simple method, based on a sugar glass fugitive ink loaded with calcium chloride to build sacrificial molds, is presented. We used a dual calcium cross-linking process by adding this highly soluble calcium source in the printed sugar, thus allowing the rapid gelation of a thin membrane of alginate around the sugar construct, followed by the addition of calcium carbonate and gluconic acid δ-lactone to complete the process. This innovative technique results in the rapid formation of "on-demand" alginate hydrogel with complex fluidic channels that could be used in biomedical applications such as highly vascularized scaffolds promoting pathways for nutrients and oxygen to the cells.

Cake Baking with Alternative Carbohydrates for Potential Sucrose Replacement. I. Functionality of Small Sugars and Their Effects on High‐Ratio Cake‐Baking Performance

For exploring the effects of sugar type on predictive differential scanning calorimetry (DSC), rapid viscoanalysis (RVA), and cake baking, including time‐lapse photography analyses, xylose, glucose, fructose, and sucrose were selected as a diagnostic series of small sugars. The effects of chlorination on solvent retention capacity, wheat flour starch gelatinization, and pasting, and of sucrose particle size on cake baking, were also examined. DSC and RVA results showed that 50 w% sugar solutions retarded starch gelatinization and enhanced starch pasting, respectively, for nonchlorinated and chlorinated flours. Chlorination did not affect starch gelatinization but enhanced earlier pasting and resulted in higher viscosity. Cake baking with chlorinated flour showed a similar pattern for height of cake center and height of cake edge but a different pattern for cake shape factor. More rapid sugar dissolution of sucrose with smaller particle size resulted in exaggerated collapse. The use of time‐lapse photography and interpretation of the expansion profiles during baking of cakes made with the diagnostic series of sugars led to a deeper understanding about cake‐baking performance, which makes it possible to relate RVA behavior in diagnostic sugar solutions to cake‐baking potential and to guide wheat‐breeding efforts to provide functional flours for baking of high‐ratio‐type cakes.

What would happen if we strew sugar in water or oil? Predictions and drawings of pre-schoolers

In this article, we will present a research on the tracing of pre-school students’ mental representations on the phenomenon of dissolution of solids in a liquid. Thirty-one children drawn out of four different kindergarten classes participate in this research. The main subject of this research was the listing and ranking of 5-6 year old children’s representations, when called to predict problems concerning the dissolution of a solid substance in two different liquids (water or oil). The approach was qualitative and the research was carried out based on personal interviews and children’s drawings. The results showed that a significant percentage of the subject sample does not detect differences between the dissolution of sugar in water or oil, that there are major differences when children draw or predict and that while in their drawings children seem to comprehend the preservation of sugar in the solution, in their predictions many of them view that sugar is not preserved.

ChemInform Abstract: Enzymatic Synthesis of Sugar Fatty Acid Esters in Ionic Liquids

AbstractReview: 40 refs.

Effect of Cooking on Moisture Sorption Isotherms of Sheanut (Vitellaria paradoxa Gaertn.) Kernels: Evidence from Light and Scanning Electron Microscopy

The standard static gravimetric method was used to determine moisture sorption isotherms of both raw and cooked sheanut kernels at 40, 50 and 60 °C in the water activity range 0.11–0.96 in order to evaluate the influence of cooking on the moisture sorption capacity of the kernels. Preliminary analysis showed that the kernels lost a significant quantity of its proteins and carbohydrate during the cooking process. Results of analysis of the moisture sorption isotherms revealed that cooked kernels generally had significantly (p < 0.05) lower equilibrium moisture contents (EMC) than the raw ones for both desorption and adsorption processes. The effect of temperature on the sorption processes as portrayed by the desorption isotherms revealed that EMC decreased steadily with increase in temperature within the water activity range 0.10–0.8 aw but increased rapidly with increase in temperature above 0.8 aw resulting in the overlap of isotherms for all sorption processes. This crossing over of isotherms was attributed to the dissolution of sugars at higher water activities. The protein matrix in the kernel was observed using light microscopy and was found to have been disorientated after cooking. Studies using light and scanning electron microscopy revealed that the reduced ability of cooked kernels to sorb water could be linked to changes in the structure of the kernels brought about by the cooking of the kernels. It is concluded that cooking had a very significant effect on the amount of water sorbed by sheanut kernels.

Effect of Cellulase Pretreatment on Alkali-Oxygen Pulping of Bagasse

In this paper, the process of cellulase pretreatment before alkali-oxygen pulping of bagasse was studied. The effect of cellulase pretreatment on subsequent pulping was also researched. The results showed that some small-sized components and sugars dissolved into the effluent in the process of cellulase pretreatment. UV spectroscopy showed that there was no significant lignin content in the pretreatment effluent.It was also found that pulping properties were promoted when the cellulase dosage was 2 ECU/g pulp, in that under the same cooking conditions, pulp kappa number was decreased by 1.3 and pulp brightness was increased by 2.5 %ISO, while the viscosity of pulp also increased slightly. Moreover, the tensile index, tear index and folding endurance were increased by 8%, 7% and 30%, respectively, but burst index showed no significant change. The above results illustrated that cellulase pretreatment was only beneficial to the dissolution of sugars and fine components from bagasse and it was an effective method of promoting alkali-oxygen pulping of bagasse.

Enzymatic synthesis of sugar fatty acid esters in ionic liquids

Sugar fatty acid esters are nonionic biosurfactants widely used in food, cosmetic and pharmaceutical industries. Ionic liquids (ILs) have shown great potential as an alternative reaction medium to conventional organic solvents for their enzymatic synthesis, promoting a significant enhancement in sugar solubility, enzymatic reactivity and regioselectivity. In this perspective, we summarize the advances in the use of ILs as a solvent for sugar dissolution and lipase-catalyzed sugar ester synthesis, review the recent achievements in designing enzyme-compatible ILs for the synthesis, and discuss the challenges that the research on this topic is facing. Among the advanced ILs, deep eutectic solvents (DESs) merit a serious consideration as a potential reaction medium for this application.

Kinetic modeling of glucose and fructose dissolution in 2-methyl 2-butanol

With the objective of developing simulation models for sugar bioconversion processes in non-aqueous media, the present study investigated the dissolution kinetics of glucose and fructose in 2-methyl 2-butanol at temperatures between 20 °C and 80 °C. For both sugars a two-phase dissolution process was observed, characterized by an initially fast dissolution lasting a few minutes, followed by a much slower dissolution phase extending up to 24 h. The experimental results are described by a combined sugar dissolution and mutarotation kinetic model that considers the dissolution of the sugar anomeric form present in the solid particles, namely α- d-glucopyranose and ß- d-fructopyranose, and its subsequent mutarotation in solution. The initial dissolution step is assumed limited by the solute transport from the surface to the bulk solution, and the corresponding sugar transport coefficient evaluated from established mass transport correlations. The second slower dissolution phase is solely controlled by the sugar mutarotation rate, and modeled as a first-order reversible reaction. The determined values of the mutarotation rate and equilibrium constants can be related to the solution temperature by an Arrhenius and Van’t Hoff relationship, respectively.

Anomalous dissolution behaviour of tablets prepared from sugar glass-based solid dispersions

In this study, anomalous dissolution behaviour of tablets consisting of sugar glass dispersions was investigated. The poorly aqueous soluble diazepam was used as a lipophilic model drug. The release of diazepam and sugar carrier was determined to study the mechanisms governing dissolution behaviour. The effect of carrier dissolution rate and drug load was tested with four different sugars, in the order of decreasing dissolution rates: sucrose, trehalose and two oligo-fructoses; inulinDP11 and inulinDP23 having a number average degree of polymerization (DP) of 11 and 23, respectively. Diazepam was incorporated in these sugar glasses in the amorphous state by means of freeze drying using water and tertiary butyl alcohol (TBA) as solvents. None of the tablets disintegrated during dissolution. Dissolution of 80% of the lipophilic drug within 20 min was found when diazepam and sugar dissolution profiles coincided. The sugar carrier and diazepam dissolved at the same rate, which was constant in time and fast. This condition was met for relatively slow dissolving carriers like the inulins or for low drug loads. For relatively fast dissolving carriers like sucrose or trehalose with high drug loads, release profiles of diazepam and sugar did not coincide: diazepam dissolved much more slowly than the sugars. In case of non-coinciding release profiles, diazepam release was split into three phases. During the first phase non-steady-state dissolution was observed: diazepam release accelerated and a drug rich layer consisting of crystalline diazepam was gradually formed. This first phase determined the further release of diazepam. During the second phase a steady-state release rate was reached: zero-order release was observed for both drug and carrier. During this phase, the remaining (non-crystallised) solid dispersion is dissolved without the further occurrence of crystallisation. The third phase, starting when all carrier is dissolved, involved the very slow dissolution of crystallised diazepam, which was present either as the skeleton of a tablet resulting in a zero-order release profile or as separate particles dispersed in the dissolution medium resulting in a first-order release. To understand the anomalous dissolution behaviour, a model is proposed. It describes the phenomena during dissolution of amorphous solid dispersion tablets and explains that fast dissolution is observed for low drug loads or slow dissolving carriers like inulin.

THE ROLE OF PARTICLE SIZE DISTRIBUTION OF SUSPENDED SOLIDS IN DEFINING THE SENSORY PROPERTIES OF MILK CHOCOLATE

The melting of chocolate in the mouth is a dynamic process. The time evolution of the perceived flavor and texture of chocolate during fat melting and sugar dissolution has been observed and quantified using time-intensity sensory methodology. Five milk chocolates varying in particle size distribution and rheology were prepared. Additionally, two chocolates varying in particle size were standardized to the same viscosity. Particle size and rheology significantly influenced effort, thickness, chocolate and sweetness attributes, although in some unanticipated ways. Averaging time-intensity responses to produce consensus curves generally yielded the same conclusions as averaging parameters extracted from individual curves. However, the later were amenable to statistical analysis using ANOVA and partial least squares regression. Multivariate analysis was a useful technique for identifying those physical properties most correlated with sensory perception.

Water sorption isotherms of date pastes as influenced by date cultivar and storage temperature

The water sorption isotherms of pastes of three date cultivars – Ruziz, Khudari, and Khlass – were determined using the static method of saturated salt solutions at three storage temperatures: 5°C, 25°C and 40°C. The effect of temperature on sorption behavior was more pronounced than the effect of date cultivar. Equilibrium moisture content decreased with increasing temperature at water activities below 0.45–0.55. However, above 0.45–0.55, equilibrium moisture content increased with increase in temperature, mainly due to the additional dissolution of sugars at higher temperatures. The experimental data fitted well with GAB, Iglesias and Chirife, and Halsey equations, suitable for high sugar foods.