Sucrose particle sizes

In the sugar industry, where the goal is to determine the exact amount of sucrose present, the analysis of other components is essential to determine purity. The most important of these, besides reducing sugars discussed, are moisture, ash, and color. Also relevant are methods used to determine particle-size distribution and insoluble matter. 

O Sullivan discussed the influence of particle size on quantitative Raman monitoring in slurries [40], A system of P-form D-mannitol in toluene in the presence of sucrose was studied. It was found that although keeping the number and size of mannitol crystals constant the measured Raman signal varied with different particle size of the sucrose. These results show that particle size must always be taken into consideration in quantitative measurements and a linear relationship can not be taken for granted. 

The amperometric detection of sucrose was performed with a conventional three-electrode potentiostatic system. With an LC-3D voltammo-graph (Bioanalytical Systems). The working electrode was a 2-mm diameter platinum disc, polished with alumina down to 0.05 pm particle size and rinsed thoroughly with distilled water, the reference electrode was an Ag/AgCl (3M KC1) electrode and the auxiliary electrode was a stainless-steel rod. 

Figure 5. Particle size distribution of a mixture of polystyrene latexes with nominal diameters of 0.804 and 1.09 pm obtained by disk centrifugation at 4000 rpm in a 1/4% sucrose gradient.

Particle density can alternatively be evaluated from a set of retention measurements made in carriers of different density (1J5). Such density modifications are typically accomplished by successive additions of sucrose to the carrier. The observed retention values yield particle size and density through Equation 2. A rearrangement of this equation leads to a graphical procedure for size/density evaluation. The rearranged form is... 

Previous studies of our work group demonstrated that isomaltose exhibits a distinct higher affinity towards certain dealuminated p-zeolites as opposed to other carbohydrates like fructose or glucose [94, 109]. Sucrose is not adsorbed at all. As a consequence, a process could be developed which directly removes the isomaltose from the reaction solution by adsorption onto zeolite. For this purpose a fluidized bed reactor has been utilized with a special focus on the separation of the two solid phases (Fig. 14). The biocatalyst containing entrapped dextransucrase is produced by the jet-cutter method [110] the alginate beads have a mean particle size of 0.5 mm. To accomplish an adequate high density of biocatalyst, silica flour (30% w/v) is included. The particle diameter of the second solid phase (zeolite) is adjusted to 10 pm. As a consequence, zeolite is loaded with isomaltose inside the reactor and can then freely exit the reactor together with the product solution, whereas the biocatalyst is retained inside the fluidized bed reactor [92, 94],... 

Confectionery factories normally use sucrose in a number of forms (for examples of particle size and forms commonly used in different confectionery products see Tables 3.2 and 3.3) granulated, i.e. crystalline milled sugar, icing sugar and possibly a 66% sugar syrup (see also... 

Three particle systems were examined by image analysis and their aspect ratio and particle size distributions were measured [197,198]. The data were then used as a reference method for neural networking using a Malvern Mastersizer X and concentrations from 2 g f to 60 g I" . Particle shapes ranged from an ellipsoidal cracking catalyst, needle shaped asbestos and monoclinic sucrose crystals. 

Particle size distribution powdered sucrose is a white, irregular-sized granular powder. The crystalline material consists of colorless crystalline, roughly cubic granules. See Figures 2 and 3. 

Particle size distribution for Di-Pac, 3% maximum retained on a 40 (425 pm) mesh 75% minimum through a 100 (150 pm) mesh 5% maximum through 200 (75 pm) mesh. Solubility the sucrose portion is water-soluble. 

Particle size was also evaluated in encapsulated materials by comparing single- and double-encapsulated butter oil powders in sucrose (<500 pm and 1000 pm, respectively) by Onwulata et al. (1998). Compressibility as a measure of cohesion and mechanical strength at various loads increased for both single-encapsulated powders and double-encapsulated powders. However, larger powders were more impeded in flow than single-encapsulated ones. 

Flow problems are mainly dependent on interparticle/intraparticle forces, powder particle size and shape, and moisture and fat content. Conditioners (or anticaking agents) enhance powder flow by reducing interparticle force cohesiveness and compressibility while increasing bulk density (Peleg and Manheim, 1973). Peleg et al. (1973) showed that as concentrations of stearate or silicate (added to sucrose) were increased from 1% to 3%, there was no reduction in cohesiveness at agent concentrations of 1-2%, but cohesiveness decreased as more flow conditioner was added. 

A weakness, common to all Karl Fischer-type methods, lies in the limitation that they measure the total water content of the sample, irrespective of the water distribution within the sample. In solids that are partially crystalline and partially amorphous, the residual water will be concentrated in the amorphous phase, thus depressing its Tg. This can accelerate or even promote the crystallisation of small molecule substances within the amorphous matrix. Take as an example crystalline sucrose that contains 0.5% of amorphous material and 0.17% of residual water. Since all the water is concentrated in the amorphous phase, the real water content will be 20% with a Tg of 9°C. It is also instructive to calculate the number of water molecule layers for differently sized sucrose particles. This is shown in Table 1. If the measured water content were to rise to 0.5%, corresponding to 50% in the amorphous phase, then Tg of the amorphous phase would be depressed to —70°C. It is therefore useful, if not essential, to have a reasonable estimate of the amorphous content of a preparation. Several more or less laborious methods for its determination hnd application, and they are... 

---