Concentrated Sucrose Solutions Research Articles

How honey bees dip nectar: Dynamic spacing of tongue hairs facilitates to collect nectar of various viscosities

A honey bee can dip nectar of viscosity across two orders of magnitude, by viscous lapping technique using a segmental tongue covered with erectable hairs. The drinking technique suffers risks of leakage occurring between tongue hairs, and the amount of leakage is related to hair spacing as well as nectar viscosity. When lapping, tongue segments are elongated, which enlarges the hair spacing in longitudinal direction. Experimental observations show that the hair spacing of tongue increases with respect to sucrose solution concentration until it reaches the maximum extension when sucrose solution concentration is above 35%. Considering leakage occurring in the hairy tongue, we hypothesize that the dynamical extension of hair spacing may help honey bees minimize the effects of leakage to reach maximal nectar intake rate. A mathematical model is developed for determining the optimal hair spacing that can meet the demands of both augmenting the nectar intake rate and reducing the risk of leakage. Theoretical prediction and experimental measurements demonstrate honey bees are able to adjust the tongue to meet the optimal hair spacing when dipping nectar of concentration more dilute than 35% and maintain a maximum extension to improve the nectar intake rate when concentration is greater than 35%. We then give the prediction of concentration preferences of three bee species, and discuss effects of dipping frequency and gravity on the leakiness between tongue hairs. This work may not only gain insights into adaptive feeding strategy in insects, but inspire the design of adaptive microfluidic transport devices with dynamic brushy surfaces.

Effects of sugar sources on adult longevity, survival and related gene expression in an endoparasitoid, Pteromalus puparum (Hymenoptera: Pteromalidae)

Adult parasitic wasps take sugars to meet their energy needs and display different lifespans and fertility in response to different sugar sources. Pteromalus puparum is an endoparasitoid with a wide range of hosts, including many lepidopteran pests. As a potential natural enemy resource, the availability of sugar sources has profound effects for wasp applications and host populations dynamics. We assessed the effect of feeding sucrose and honey on the lifespan of P. puparum in the range 0-40% (w/v). The results indicated a statistically significant positive effect of sucrose and honey solutions on the lifespan of P. puparum female adults. Correlation analyses confirmed a strong positive correlation between high concentrations of sugar and extended lifespan. The optimum concentration of sucrose solution for wasps was 20%, while 10% for honey. Then, we examined the expression patterns of 15 lifespan-related genes. The results showed that the relative expression levels of 14 genes were significantly correlated with the mean lifespan of sucrose-fed wasps, and six genes correlated with the mean lifespan of honey-fed wasps. In addition, the models for lifespan prediction were constructed. We elaborated the quantitative effects of two sugar sources (sucrose and honey) on P. puparum lifespan, investigated the expression patterns of lifespan-related genes when fed different sugar sources, and developed round lifespan prediction models accordingly. This study provides a novel tool for studying the longevity regulating mechanisms of parasitic wasps, and may be instructive for mass-production of parasitoids as biological control agents. © 2020 Society of Chemical Industry.

Choice between different concentrations of sucrose in an adjusting-magnitude schedule: Evidence for reinforcer-specific value maxima

According to the Multiplicative Hyperbolic Model (MHM), an extension of Mazur’s (1987) model of delay discounting, the value of a reinforcer is an increasing hyperbolic function of its size (q). This experiment tested a prediction based on a revised version of MHM (MHM-R), according to which the maximum value may differ between different reinforcers, a possibility not envisaged in MHM. Rats were trained under a discrete-trials adjusting-magnitude schedule in which a response on lever B delivered a dilute sucrose reinforcer (0.2 M) of fixed volume, qB, while a response on lever A delivered a more concentrated sucrose solution (0.4 M) the volume of which, qA, was adjusted according to the rats’ choices. When B was preferred in a given block of trials, qA was increased in the following block; when A was preferred, qA was reduced in the following block. qB was varied across four phases of the experiment and the corresponding indifference magnitudes of A (qA(50)) were measured. In keeping with expectations based on both MHM and MHM-R, qA(50) increased approximately linearly with qB, and 1/qA(50) with 1/qB. The ratio qB/qA(50) increased linearly with qB with a positive intercept, a finding that is consistent with MHM-R but not with MHM.

Evaluation of viscosity and surface tension of low-volume samples using glass capillary

In this paper, methods for measuring the viscosity and surface tension of low-volume liquid samples are proposed. Viscosity is measured by recording the motion of a liquid driven by surface tension through a horizontal glass capillary tube. Surface tension is determined by connecting a container of a constant volume to the distal end of the capillary tube and measuring the penetration distance of the liquid entering via the proximal end. Sucrose solutions of various concentrations (0–50 wt%) were measured as samples, and the determined viscosities were confirmed to be consistent with the tabulated values provided in the Handbook of Chemistry. The surface tension was found to be constant within the measurement sensitivity of the device regardless of the sucrose concentration.

Differences in Sweet Taste Perception and Its Association with the Streptococcus mutans Cariogenic Profile in Preschool Children with Caries.

The aim of the study was to verify the hypothesis about differences in sweet taste perception in the group of preschool children with and without caries, and to determine its relationship with cariogenic microbiota and the frequency of sweets consumption in children. The study group included of 63 children aged 2–6 years: 32 with caries and 31 without caries. The study consisted of collecting questionnaire data and assessment of dental status using the decayed, missing, filled in primary teeth index (dmft) and the International Caries Detection and Assessment System (ICDAS II). The evaluation of sweet taste perception was carried out using a specific method that simultaneously assessed the level of taste preferences and the sensitivity threshold for a given taste. The microbiological analysis consisted of the assessment of the quantitative and qualitative compositions of the oral microbiota of the examined children. The sweet taste perception of children with caries was characterized by a lower susceptibility to sucrose (the preferred sucrose solution concentration was >4 g/L) compared to children without caries (in the range ≤ 4 g/L, p = 0.0015, chi-square test). A similar relationship was also observed for frequent snacking between meals (p = 0.0038, chi-square test). The analysis of studied variables showed the existence of a strong positive correlation between the perception of sweet taste and the occurrence and intensity of the cariogenic process (p = 0.007 for dmft; and p = 0.012 for ICDAS II), as well as the frequency of consuming sweets (p ≤ 0.001 for frequent and repeated consumption of sweets during the day, Spearman test) in children with caries. Additionally, children with an elevated sucrose taste threshold were more than 10-times more likely to develop S. mutans presence (OR = 10.21; 95% CI 3.11–33.44). The results of this study suggest the future use of taste preferences in children as a diagnostic tool for the early detection of increased susceptibility to caries through microbial dysbiosis towards specific species of microorganisms.

Effects of cryoprotectants on Nostoc sphaeroides superchilled at low temperature (−3.0°C) and their action mechanisms

AbstractEffects of cryoprotectants (NaCl, sucrose and trehalose) on Nostoc sphaeroides (N. sphaeroides) superchilled at −3.0°C as well as their action mechanisms were studied. Prior to storage, N. sphaeroides were immersed into different concentrations (5% and 10%) of NaCl solutions, sucrose solutions, and trehalose solutions for 2 hr. The texture properties, drip loss and low field nuclear magnetic resonance (NMR)‐imaging of N. sphaeroides with different treatments were evaluated. The freezing point, solute absorption, water distribution and microscopic structure were also measured to illustrate the action mechanisms of cryoprotectants. Results suggested that cryoprotectants offered an effective method for keeping the texture properties, lowering drip loss, and maintaining the shape of N. sphaeroides. Among all the cryoprotectants used, 5% NaCl exhibited the best effect. The study of their action mechanisms showed that cryoprotectants were efficient in reducing the freezing point, the proportion of free water and microscopic structure destruction of N. sphaeroides.Practical ApplicationsConsidering the higher water content of N. sphaeroides, it is not suitable to be deeply frozen because the formation of numerous ice crystals can cause severe damages to the tissue. To suppress these undesirable changes in superchilling, cryoprotectants including NaCl, sucrose and trehalose are added to the food products. This research contributes to lay a theoretical foundation for the further study of superchilling storage of N. sphaeroides.

Experimental quantum polarimetry using heralded single photons

We perform experimental quantum polarimetry using a heralded single photon to analyze the optical activity of linearly polarized light traversing a chiral medium. Three kinds of estimators are considered to estimate the concentrations of sucrose solutions from measuring the rotation angle of the linear polarization of the output photons. Through repetition of independent and identical measurements performed for each individual scheme and different concentration sucrose solutions, we compare the estimation uncertainty among the three schemes. The results are also compared to classical benchmarks for which a coherent state of light is taken into account. The quantum enhancement in the estimation uncertainty is evaluated and the impact of experimental and technical imperfections is discussed. In this work, we lay out a route for future applications relying on quantum polarimetry.

Process Monitoring of Antisolvent Based Crystallization in Low Conductivity Solutions Using Electrical Impedance Spectroscopy and 2-D Electrical Resistance Tomography

Industrial process monitoring is an important field of research where different chemical processes are monitored and controlled. In this work, electrical impedance spectroscopy (EIS) was used to analyze antisolvent based crystallization of sucrose solutions. The impedance and phase spectra were recorded for four known sucrose concentrations in water, and for each case, four predetermined amounts of ethanol were added. As a result, sixteen different solutions involving sucrose solutions of different concentrations and ethanol to water ratios were analyzed. Significant differences were observed in the magnitude and phase spectra of the solutions in the frequency range of 50 kHz to 300 kHz. The experimentally obtained data from the EIS were converted into frequency response models. Three continuous-time transfer function models of the first-order, second-order, and a second-order with a zero were estimated and compared. In addition, a 2-D electrical resistance tomography (ERT) system with a low conductivity sensor unit was designed and tested with demineralized water, tap water and industrial food grade saturated sucrose solution. Non-conducting phantom and sugar crystals were observed within the saturated sucrose solution using the Bayesian reconstruction algorithm. These demonstrations have the potential to be developed into a multi-frequency ERT systems for monitoring the distribution of the crystals in the reactor. The EIS modality can be a complementary process analytical technology (PAT) tool indicating supersaturation status and provide quality assurance.

Solute inclusion and freezing rate during progressive freeze concentration of sucrose and maltodextrin solutions

Progressive freeze concentration is an alternative method to concentrate aqueous industrial streams compared to evaporation or membrane separation. In this research sucrose and maltodextrin solutions were concentrated in a stirred progressive freeze concentrator. The solute inclusion in the formed ice was studied using varying stirring speeds, initial concentrations and freezing plate temperatures. Under constant freezing plate temperature, a lower limit was found for the solute inclusions with increasing stirrer speeds. To improve the freeze concentration process, a decreasing temperature ramp was applied to the freezing plate. This yielded 2 to 3 times less solute inclusions in the ice, while maintaining similar ice yields.

Metasurface-enhanced ATR sensor for aqueous solution in the terahertz range

A metasurface-enhanced aqueous solution sensor based on attenuated total reflection (ATR) in the terahertz (THz) range was investigated theoretically and experimentally. The metasurface consisting of complementary split rings is lithographed directly on the upper surface of the ATR prism, and the metasurface-enhanced ATR sensor shows great advantages in detecting aqueous solution comparing with the sensor based on either the split rings or the conventional ATR. The concentration of sucrose solution from 1 mol/L to 0.03125 mol/L has been measured, and the detection sensitivity of metasurface-enhanced ATR is 4 times higher than that of the conventional ATR. This design has significant advantages in solution sensing and exhibits great potential for ultrasensitive aqueous biosensor applications.

Acute Sleep Curtailment Increases Sweet Taste Preference, Appetite and Food Intake in Healthy Young Adults: A Randomized Crossover Trial.

This study aimed to examine the effect of acute sleep curtailment on sweet taste preference, appetite and food intake, and the correlation between food intake and sweet taste preference or active ghrelin using a randomized crossover design (5 h sleep curtailment vs. 8 h control). Twenty-four participants (11 men) aged 21.4 ± 1.0 years, with BMI 19.8 ± 1.7 kg/m2, who habitually slept 5 h/night or more experienced interventions lasting three consecutive nights. Participants came into the laboratory for testing on day 4. Fasting blood tests were conducted at 8:00 a.m. to measure active ghrelin and leptin levels. Sweet taste preference was assessed by presenting five different concentration sucrose solutions at 9:00 a.m. Ad libitum intake at breakfast was assessed for 30 min from 9:30 a.m. Sweet taste preference was higher following sleep curtailment than control. Active ghrelin was likewise higher following sleep curtailment than control. Leptin did not differ between conditions. Energy intake was higher following sleep curtailment than control, being derived primarily from carbohydrates. However, sweet taste preference and active ghrelin did not correlate with energy intake. These results suggest that acute consecutive sleep curtailment increases sweet taste preference, active ghrelin, and energy intake in healthy young adults.

Lossy Mode Resonance-Based Refractive Index Sensor for Sucrose Concentration Measurement

A detailed analysis of Prism/LiF/ZnO structure based lossy mode resonance sensor is presented for measurement of sucrose concentration. Theoretical and experimental studies using angular interrogation technique has been carried out to achieve high sensitivity for a range of surrounding medium refractive indices (1.33-1.45). Simulation outcomes reveal that a low refractive index layer of LiF may be introduced between substrate and the absorbing film of ZnO to develop a high sensitivity refractive index sensor. Various sensor configurations at different thicknesses of LiF are investigated for both s- and p- polarizations of light at the wavelength of 632.8 nm. The best obtained sensor configurations have been developed experimentally to measure concentration of sucrose solution. The maximum sensitivities of 61.92 °/RIU for s- polarization and 68.80 °/RIU for p-polarization are obtained experimentally, which are found to be in close agreement with the theoretically simulated results.

Rheological properties of stabilizers at low temperatures in concentrated sucrose solutions

During the freezing of sorbets, the concentration of sucrose and stabilizing macromolecules increases in the unfrozen phase. Rheological properties of this unfrozen phase were studied, depending on nature and concentration of hydrocolloids in sucrose solutions at temperatures below zero. Three stabilizers were tested individually in sucrose-rich solutions: locust bean gum (LBG), hydroxypropylmethylcellulose (HPMC) and carboxymethylcellulose (CMC). The parameters of the Ostwald-de Waele model were determined and apparent viscosities of solutions were calculated at shear rates encountered during the process. Intrinsic viscosities and critical concentrations of entanglement were determined to evaluate the expansion of polymers in solutions and the transition of concentration regimes according to process conditions. Viscoelastic properties were also tested to study the possible cryogelation. For HPMC and LBG, the shear thinning behavior increased quite linearly with the concentration in stabilizer whereas CMC was highly shear thinning. Increasing sugar did not reveal large effect on these properties. The increase in apparent viscosity of the unfrozen matrix in process conditions was dependent on stabilizers; solutions containing LBG were less viscous than the others. Intrinsic viscosities revealed that HPMC and LBG became progressively less expanded as the concentration of sucrose increased whereas CMC tended to aggregate. Measurements of viscoelastic properties evidenced a dominant viscous behavior for HPMC and LBG systems whereas CMC systems showed dominant elastic behavior at frequencies higher than 0.1 Hz. The next challenge will be to better understand the potential link between the particular rheological behavior of hydrocolloids in process conditions and their possible influence on crystallization mechanisms.

Effect of short-term intake of high- and low-concentrations of sucrose solution on the neurochemistry of male and female mice.

The effect of short-term intake of high- and low-concentrations of sucrose solution on the neurochemistry of male and female mice was studied. The body weight, feed intake, sucrose solution consumption and brain monoamine neurotransmitters were determined after 34 days' intake of 1% and 8% sucrose solutions. The gene expression and protein levels related to dopamine and opioids were also determined. The results showed that the intake of 1% and 8% sucrose solution for 34 days did not cause significant changes in the weight development of both male and female mice. The preference for sucrose varies with sex. Both males and females had greater preference for the high concentration sucrose solution than the low concentration sucrose solution. The continuous intake of sucrose stimulated the release of monoamine neurotransmitters (DA, 5-HT, NE) in the brains of mice, and the reward effect of 8% sucrose solution is significantly higher than that of 1% sucrose solution. The sex of mice did not affect the release of neurotransmitters. The gene expressions of D1 and D2 were up-regulated in the 1% sucrose group of male mice, while the OPRM1 gene expression was down-regulated. The expression of these three genes in the 8% sucrose group of male mice was all down-regulated, while the gene expressions of D1 and D2 in the 1% and 8% sucrose group (p < 0.05) of female mice were both up-regulated.

Trail pheromone modulates subjective reward evaluation in Argentine ants.

The Argentine ant, Linepithema humile, is native to South America but has become one of the most invasive species in the world. These ants heavily rely on trail pheromones for foraging, and previous studies have focused on such signals to develop a strategy for chemical control. Here, we studied the effects of pre-exposure to the trail pheromone on sugar acceptance and olfactory learning in Argentine ants. We used the synthetic trail pheromone component (Z)-9-hexadecenal, which triggers the same attraction and trail-following behavior as the natural trail pheromone. We found that pre-exposure to (Z)-9-hexadecenal increases the acceptance of sucrose solutions of different concentrations, thus changing the ants' subjective evaluation of a food reward. However, although ants learned to associate an odor with a sucrose reward, pheromone pre-exposure affected neither the learning nor the mid-term memory of the odor-reward association. Taking into account the importance of the Argentine ant as a pest and invasive organism, our results highlight the importance of pheromonal cues in resource evaluation, a fact that could be useful in control strategies implemented for this species.

INFLUENCE OF EXOGENOUS SUCROSE EXPOSURE ON THE PHLOEM FORMATION OF SILVER BIRCH, GREY ALDER AND ASPEN

The study is a continuation of a series of experiments to identify the role of sucrose in the anomalous morphogenesis of conducting tissues of deciduous woody plants. Previously it was found that the exposure of the trunk tissue to solutions with a high concentration of sucrose causes birch and alder to form xylem, which has common features with the figured woods of these species, while aspen xylem does not differ in structure from typical wood. In this paper, the effect of sucrose solutions of various concentrations on the phloem formation is analyzed. In alder and aspen, high concentrations of sucrose (10% and 20%) was found to have no effect on the structure of the late phloem; the reaction of these species was manifested through a change in the functional state of parenchyma cells (an appearance of large central vacuole, accumulation of starch). At the same time there was a tendency to enhance parenchymatization of the birch late phloem with increasing concentration of sucrose in the solution, but the observed differences were not significant. In all studied species, in the variants with a sucrose concentration 1% - 5%, sclerenchyma elements differentiated in the conductive phloem, the latter is a structural anomaly for birch, but typical for alder and aspen. It was concluded that with an increase in the concentration of sugars in the cambial zone of birch above a certain threshold value, their utilization within the framework of the previous structure of tissues is not enough, and the formation of new storage cells and sclereids occurs. It has been suggested that alder and aspen have mechanisms that maintain the level of sucrose within the limits necessary for normal phloemogenesis, one of which, apparently, is the formation of thick-walled sclerenchyma elements. The difference in the metabolites stored by parenchyma cells under the experimental conditions is only a reason to believe that a large excess of sugars is normally absent in the tissues of the trunk of grey alder and aspen.

Effects of different concentrations of sucrose and citric acid on vase life of rose

Vase life is the most important parameter to determine the quality of cut flower, however, due to highly perishable nature is always challenging to vase life. An experiment was conducted at Horticulture Lab, Prithu Technical College, Dangon 2018 in order to find out best concentration of sucrose and citric solution that enhances and prolongs the better flower quality and longevity. Experiment was laid out in completely randomize design (CRD) with nine treatments and three replication. Rose sticks were harvested at flower bud stage and two sticks were kept in each vase solution. 2% sucrose with 15 ppm citric acid solution found longest vase life and this combination has the potential to be used as a commercial cut flower preservative solution to delay flower senescence, enhance post-harvest quality and prolong the vase life of cut rose flowers.

OSMOTIC DEHYDRATION OF MANGO SLICES IN SUGAR SOLUTION USING RESPONSE SURFACE METHODOLOGY

The response surface methodology (RSM) was applied to optimize the effects of immersion time (01, 02 and 03 hr), temperature (40, 50 and 60 ⁰C) and concentration of sucrose solution (40, 50 and 60⁰Brix) in osmotic dehydration of mango fruit slices (3mm thickness). Box-Behnken Design was used with water loss (WL, %), solid gain (SG, %), and weight reduction (WR, %) as responses. The models obtained for all the responses were significant (P≤0.05) without a significant lack of fit. The optimum conditions were temperature (50°C), immersion time (2hr), concentration of sucrose solution (56.756⁰Brix) in order to obtain WR of( 32.75 g/100g initial sample), SG of (18.799g/100g initial sample) and WL of (51.551g/100g initial sample), respectively.

Ultrasound-Assisted Osmotic Dehydration of Apples in Polyols and Dihydroxyacetone (DHA) Solutions

The aim of this work was to analyse the effect of ultrasound-assisted osmotic dehydration of apples v. Elise on mass transfer parameters, water activity, and colour changes. Ultrasound treatment was performed at a frequency of 21 kHz with a temperature of 40 °C for 30–180 min using four osmotic solutions: 30% concentrated syrups of erythritol, xylitol, maltitol, and dihydroxyacetone (DHA). The efficiency of the used solutes from the polyol groups was compared to reference dehydration in 50% concentrated sucrose solution. Peleg’s model was used to fit experimental data. Erythritol, xylitol, and DHA solutions showed similar efficiency to sucrose and good water removal properties in compared values of true water loss. The application of ultrasound by two methods was in most cases unnoticeable and weaker than was expected. On the other hand, sonication by the continuous method allowed for a significant reduction in water activity in apple tissue in all tested solutions.

Yardımcı gıda teknolojileri ile elmadan probiyotik atıştırmalık üretiminin ön çalışması

A probiotic snack model food was formed with apple and Lactobacillus rhamnosus GG (LGG). The effects of dehydration process conditions with design of experiment (DoE) and dryer types used in the production were evaluated through optimization and probiotic qualification of the final product. Experiments on ultrasound assisted osmotic dehydration (US-OD) of apple cubes designed by Box-Behnken were conducted to obtain the maximum water reduction. Optimum values of sucrose solution concentration (40, 45, 50%), apple and solution ratio (1:4, 1:6, 1:8 w w-1) and ultrasound application time (10, 20, 30 min) variables of the design were determined. The DoE methodology introduced the results that maximum water loss was reached at the conditions of 50% sucrose concentration, 1:4 apple and solution ratio and 10.05 min; sucrose concentration was the most effective variable; quadratic model submitted a good fitting (R2=0.929) with the experimental results. Apple samples produced under the optimized conditions were dried with convectional and conventional dryers at specific temperature, 37 °C during 5 hours. The results showed that the remaining number of viable LGG cells (106-107cfu g-1) was sufficient to qualify dried products as probiotic.