Sucrose solutions

Does not reduce ammoniacal silver nitrate or Fehling s solution. If, however, the sucrose solution is warmed for some time with the reagent in question, slight hydrolysis to glucose and fructose does take place and reduction then occurs occasionally samples of sucrose will rapidly give a silver mirror, presumably owing to impurities. 

The apparent viscosity, defined as du/dj) drops with increased rate of strain. Dilatant fluids foUow a constitutive relation similar to that for pseudoplastics except that the viscosities increase with increased rate of strain, ie, n > 1 in equation 22. Dilatancy is observed in highly concentrated suspensions of very small particles such as titanium oxide in a sucrose solution. Bingham fluids display a linear stress—strain curve similar to Newtonian fluids, but have a nonzero intercept termed the yield stress (eq. 23) ... 

Polarization is the most common method for the determination of sugar in sugar-containing commodities as well as many foodstuffs. Polarimetry is apphed in sugar analysis based on the fact that the optical rotation of pure sucrose solutions is a linear function of the sucrose concentration of the solution. Saccharimeters are polarimeters in which the scales have been modified to read directiy in percent sucrose based on the normal sugar solution reading 100%. 

Equations have been developed that determine the relationship of the refractive index of sucrose solutions between 0—85% concentration, 18—40°C, and 546—589 nm. 

Table 3. Osmotic Pressure of Aqueous Sucrose Solutions at 25°C ...

Table 4. Dielectric Constant of Aqueous Sucrose Solutions...

Saccharin is the most economical sweetener available. It is 300 times (8% sucrose solution sweetness equivalence) more potent than sugar and its price in 1996 was about 6.05/kg, ca 0.02/(kg-sweet unit). Sugar, on the other hand, was ca 0.77/kg, which is 39 times more expensive than saccharin on equal sweetness basis. Consequentiy, the low cost and high stabiUty of saccharin render it the sweetener of choice for dentifrices (qv), other toiletry products, and pharmaceuticals (qv). 

Cyclamate is about 30 times (8% sucrose solution sweetness equivalence) more potent than sugar. Its bitter aftertaste is minor compared to saccharin and acesulfame-K. The mixture of cyclamate and saccharin, especially in a 10 1 ratio, imparts both a more rounded taste and a 10—20% synergy. Cyclamate (6) is manufactured by sulfonation of cyclohexylamine (7). Many reagents can be used, including sulfamic acid, salts of sulfamic acid, and sulfur trioxide (74—77). 

The disaccharide stmcture of (12) (trade name SPLENDA) is emphasized by the manufacturer as responsible for a taste quaUty and time—intensity profile closer to that of sucrose than any other high potency sweetener. The sweetness potency at the 10% sucrose solution sweetness equivalence is between 450 and 500X, or about two and one-half times that of aspartame. When compared to a 2% sugar solution, the potency of sucralose can be as high as 750X. A moderate degree of synergy between sucralose and other nonnutritive (91) or nutritive (92) sweeteners has been reported. 

Alitame (trade name Adame) is a water-soluble, crystalline powder of high sweetness potency (2000X, 10% sucrose solution sweetness equivalence). The sweet taste is clean, and the time—intensity profile is similar to that of aspartame. Because it is a stericaHy hindered amide rather than an ester, ahtame is expected to be more stable than aspartame. At pH 2 to 4, the half-life of aUtame in solution is reported to be twice that of aspartame. The main decomposition pathways (Fig. 6) include conversion to the unsweet P-aspartic isomer (17) and hydrolysis to aspartic acid and alanine amide (96). No cyclization to diketopiperazine or hydrolysis of the alanine amide bond has been reported. AUtame-sweetened beverages, particularly colas, that have a pH below 4.0 can develop an off-flavor which can be avoided or minimized by the addition of edetic acid (EDTA) [60-00-4] (97). 

Thaumatin (trade name Talin) is a very potent sweetener (ca 2000X, 10% sucrose solution sweetness equivalence). However, its potency is overshadowed by inferior taste quaUties. The onset of sweetness is very slow, and after reaching the maximum sweetness, a very long-lingering sweetness combined with an unpleasant aftertaste follows. Primarily owing to this poor taste quaUty, thaumatin is not considered a practically useflil sweetener. It is, however, used as a flavor enhancer, especially in products such as chewing gum. Thaumatin and thaumatin B-recombinant were affirmed GRAS flavors (EEMA no. 3732 and 3814, respectively). They are not approved as sweeteners in the United States. 

The shape of the equilibrium line, or solubility curve, is important in determining the mode of crystallization to be employed in order to crystallize a particular substance. If the curve is steep, i.e. the substance exhibits a strong temperature dependence of solubility (e.g. many salts and organic substances), then a cooling crystallization might be suitable. But if the metastable zone is wide (e.g. sucrose solutions), addition of seed crystal might be necessary. This can be desirable, particularly if a uniformly sized product is required. If on the other hand, the equilibrium line is relatively flat (e.g. for aqueous common salt... 

Alternative Step D Reduction with a Reductate — Sucrose (1 kg) is dissolved in water (9 liters) in a 20-liter bottle equipped with a gas trap. Baker s yeast Saccharomyces cerevisiae, 1 kg) is made into a paste with water (1 liter) and added to the sucrose solution with stirring. After lively evolution of gas begins (within 1 to 3 hours), 3-morpholino-4-(3-tert-butylamino-2-oxopropoxy)-1,2,5-thiadiazole hydrogen maleate [1.35 mols, prepared by reaction of the 3-morpholino-4-(3-tert-butylamino-2-oxopropoxy)-1,2,5-thiadiazole with an equimolar quantity of maleic acid in tetrahydrofuran]. The mixture is allowed to stand until fermentation subsides, after which the bottle is kept in a 32°C incubator until all fermentation has ended (in approximately 1 to 3 days). The yeast is filtered off with addition of diatomaceous earth and the filtrate is evaporated to dryness to give S-3-mor-pholino-4/3-tert-butylamino-2-hydroxypropoxy)-1,2,5-thiadiazole, MP 195° to 198°C (as hydrogen maleate), according to U.S. Patent 3,619,370. 

A careful examination has been made of the properties of / films when immersed in solutions of electrolytes. It was found that when a film of a pentaerythritol alkyd varnish was transferred from 0-001 N KCl to 3-5 N KCI its resistance rose, fell upon returning it to the 0-001 N KCl, rose again to the same high value when immersed in a sucrose solution isotonic with 3 - 5 N KCl and fell to the original value when returned to the dilute KCl solution (Fig. 14.3). It was concluded that the changes in resistance were dependent only upon the available water in the solution and were associated, therefore, with the entry of only water into the varnish film . 

Assume that 30 L of maple sap yields one kilogram of maple syrup (66% sucrose, C12H22Ou). What is the molality of the sucrose solution after one fourth of the water content of the sap has been removed ... 

Equation (7.123)w is often referred to as the law of Van t Hoff, since it was originally proposed by J. H. Van t Hoff. It is interesting to note that equation (7.123) is of the same form as the ideal gas equation, if one takes c as njVx Table 7.3 compares experimental values of II for aqueous sucrose solutions with those calculated using equations (7.120) and (7.123). We see that neither of the equations predicts n with high accuracy. However, the superiority of equation (7.120), especially at higher concentrations, is apparent. 

Table 7.3 Osmotic pressures of aqueous sucrose solutions at T = 293.15 K...

The constant kf is called the freezing-point constant of the solvent it is different for each solvent and must be determined experimentally (Table 8.8). The effect is quite small for instance, for a 0.1 m C12H220n(aq) (sucrose) solution,... 

FIGURE 8.31 An experiment to illustrate osmosis. Initially, the tube contained a sucrose solution and the beaker contained pure water the initial heights of the two liquids were the same. At the stage shown here, water has passed into the solution through the membrane by osmosis, and the level of solution in the tube has risen above that of the pure water. The large inset shows the molecules in the pure solvent (below the membrane) tending to join those in the solution (above the membrane) because the presence of solute molecules there has led to increased disorder. The small inset shows just the solute molecules the yellow arrow shows the direction of flow of solvent molecules. 

Seif-Test 8.13B What is the osmotic pressure of a 0.120 m sucrose solution at 298 K ... 

An important consequence of sucrose degradation is the development of color from degradation products. Kuridis and Mauch60 have developed an equation for the prediction of color development in model sucrose solutions. Color development was expressed as a function of temperature (90 to 120°C), time (0 to 80 min), pH (7.5 to 9.5), and composition of the solution (sucrose 20 to 60%, invert sugar 0.02 to 0.18%, and amino acids 1 to 3 g/L). The authors claimed, with caution, that the effects of an intended alteration in a unit process in the refinery can be predicted in advance. 

Therefore, in most cases, pH values measured at high temperatures in dilute solution should be considered approximate values only. In cases where the investigators address this problem and are careful to select a suitable electrode (namely, one that manufacturers claim to have almost hysteresis-free pH measurement and a stable isopotential point over the temperature range), the error associated with electrode performance will be small, and differences in reported pH values will correspond to differences in actual pH. In cases where pH is measured in concentrated sucrose solutions, the reported pH value should be considered as a nominal value only, and the differences in nominal pH values might not correspond to actual differences in hydrogen ion activity. 

BRIX The percentage by weight of the solids in a sucrose solution. 

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