Localization Of Sucrose And Impurities In Sugarbeet Roots

Sodium, potassium, amino acids, and reducing sugars are the major impurities in sugarbeet (Beta vulgaris L.) roots that interfere with sucrose extraction. Data showing the specific location of these impurities are limited. The objectives in this study were to determine, by analyzing specific tissues of the root, the effects of leaf removal, cultivars, and potassium fertilizer on the localized content of sucrose and various impurities. Weekly removal of older fully expanded leaves reduced the sucrose and amino acid content of the roots and increased the sodium level. Potassium content was decreased by removal of new leaves. Vascular rings near the epidermal surface of the root had the highest concentration of sucrose and the lowest level of all impurities. Pith tissue of the crown had the lowest content of sucrose and highest content of amino acids. The vascular tissue of the crown was similar in quality to the vascular tissue of the root. Cultivars and potassium fertilizers affected the sodium and potassium content of specific tissue. Impurity levels were affected by several parameters. Impurities were located in tissues where sucrose was low. Selecting genotypes with an increased amount of vascular tissue in the root and with less pith tissue in the crown should reduce the impurity levels and increase sucrose