GRANULOMETRIC COMPOSITION OF GRANULAR STARCH SWEETENERS

Abstract

There was developed a technology to produce starch sweeteners in granular form, which allows to obtain ready product in dry freeflowing state, without separation of mother liquor with valuable nutritional components, for short period of time. During granulation dextrose is crystallized on the surface of seed granules and it increases their size up to determined value, after that granules are destroyed, forming new centers of granules formation. The sizes of granules are in the range of 3–7 mm. The analysis of experimental data shows, that density of granules is decrease with increase of size of granules. Increasing the load for crushing granules at increase of their size is connected with increase of strength due to its mass increase. However, with increase of granule size the specific load per unit of cross-sectional area (tensile strength) is decreased. With increase of moisture content of granules the load for destruction is decreased. The tensile strength is decreased with increase of granule size and moisture content. The value of the optimal average granule size is determined using experimental data on change of critical stress arising inside of granules of different size, from the action of load, determined experimentally for each granule, and specific load in granules of seed layer from external forces at mixing of granule layer. Substituting the known values corresponding to experimental installation, in equations, obtained based on experimental data, we find optimal average size of granule for existing boundary conditions, obtained in the experimental installation d = 3,78 mm. The size of granule at starch sweeteners production could be change in certain limits depending on the height of seed layer of granules in granulator. The greater height of seed layer, the smaller average size of granules obtained at granulation.