Research of color characteristics of sugar production intermediates

It is known that in a sugar production, only about 80% of sucrose, extracted from the beet, is output as a commercial product. The rest is lost during the processing or remains in intermediates. The color of white sugar is mainly determined by the color of the returned to the first stage of crystallization of the brown sugars melt. An effective way to improve the quality of melt is affination of brown sugars. Coloring substances are preferably present in the film on the surface of sugar crystals. To improve the efficiency of affination experiments were carried out by layer-by-layer processing of the normalized crystal size with the saturated solution of white sugar. To evaluate the numerical characteristics of the color of the samples studied scanerometrical method followed by computer processing of images in RGB color mode was used. The studies suggest that the solution of the starting yellow sugar having visual yellow color intensively absorbs 450-480 nm of spectrum, so there is no blue component in the graphs. During the affination removing of coloring substances from the surface of crystals takes place changing the light absorption intensity. There is a bleaching of the samples at affination duration up to 3 minutes. Further 5-10 min treatment is accompanied by partial diffusion of colorants from mother liquor to the surface of crystals and improved chromaticity. Prolonged affination results in crystals abrasion; it is accompanied by unproductive energy consumption on the mixing process. The results obtained indicate that the effective removal of coloring substances occurs within 1-3 minutes of affination. In this case brown sugar chromaticity decreases from 625 to 130-230 units of optical density and mother liquor chromaticity is increased from 20 to 900-1600 units of optical density. The studies suggest that most of the coloring substances determining the chromaticity of yellow sugars is found in the film on the crystal surface and is easily removed by 3 min long affination. Method of determining of objects color characteristics in RGB system describes adequately the intermediates coloring of sugar production and can be used in research.