Extraction of sugar from a gel consisting of agar, sugar and water

On the Mechanism of Moisture Transport During Air Drying of Sugar Beet Root

“…Our assumption that the polysaccharides matrix in sugar beet root offers little additional resistance to water transport, is also supported by the results of Beverloo et al (1962). They found that the diffusion coefficient of sucrose in the agar gel system was very close to that of sucrose in water.…”

“…This could be explained considering that if Dexp does not change too much with concentration, solution of the unsteady state diffusion equation with variable diffusion coefficient, also yields-within the limits of the experimental error-a straight line when plotting the log of the moisture content versus time (Crank and Henry, 1949). This is supported by results obtained by Beverloo et al (1962) who studied the extraction of sucrose from a slab of a gel consisting of agar, sucrose (about 26%) and water. These authors used the nonstationary diffusion equation to analyze their experimental results and found that the influence of the sucrose concentration on the diffusion coefficient was not observable on the curves representing the nonextracted fraction versus time.…”

“…The mean "sucrose" concentration existing in sugar beet root during the drying period examined was considered to the effects of plotting. Beverloo et al (1962) measured the diffusion coefficients of sucrose in their model food system at various temperatures. We used their results to calculate the activation energy for diffusion, and the obtained value, 5,600 Cal/g mol, is also plotted in Figure 3.…”

Utilization of Fick's second law for the evaluation of diffusion coefficients in food processes controlled by internal diffusion

“…This approach, either for infinite slab or spheres, has been utilized by a large number of workers to calculate diffusivities from experimental drying data (Saravacos & Charm, 1962;Jason, 1965;Del Valle & Nickerson, 1968;Holdsworth, 1971;Pitkin & Carstensen, 1973;Vaccarezza, Lombardi & Chirife, 1974;Palumbo et al, 1977;Mazza & Le Maguer, 1980; as well as many others); or from leaching experiments (Beverloo, Leniger & Weldring, 1962;Pflug, Fellers & Gurevitz, 1967;Schwartzberg, 1975;Schwartzberg & Chao, 1982). In many cases experimental data adhered fairly well to the linearity predicted by the analytical solution of Fick's second law for large values of time.…”

Extraction and Quantification of Solutes in Solidified Agar Culture Media

“…Relatively few published reports have been found for assaying solutes in solidified culture media. Beverloo et al (2) and Kozima et al (5) extracted sugar from agar gels by passing solvent over the gels. The rate of extraction was dependent upon sugar concentration and increased with increase in temperature, but was not strongly influenced by solvent flow rate.…”