The quality of frost-damaged sugar beet

In manufacturing sugar from sugar beet the raw material plays the most important role as regards the production costs. The effects of beet non-sugars on sugar yield and product quality are known for “normal” beet – fresh beet or beet stored under good conditions. This is not true for frost-damaged beet which can cause problems in processing and sometimes even lead to a factory standstill. Numerous parameters were studied to find out one on which a classification of frost-damaged beet due to quality might rely. The degree of damage was defined according to the filterability of the 1st carbonation slurry. Parameters were selected according to their change with increasing degree of damage. The quality decrease is delayed at lower storage tempera-tures. According to the correlation between a parameter and the filterability the best result was found in respect of the mannitol content. The leucrose content seems to be very interesting, because the occurrence of leucrose can be correlated directly to the occurence of dextran. Most of the parameters did not differ significantly from “normal” values when the damaged status was reached first. So they cannot be used alone to distinguish undamaged and damaged beet. However higher concentrations reliably identified damaged beet. Frost-damaged beet were processed on a semi-technical scale to evaluate the consistency of the propo-sed criteria. A differentiation between damaged and undamaged beets was possible using all of the proposed criteria except the glucose content. The observed decrease in filterability correlated with the percentage of damaged beet processed. Under econo-mical aspects the process was affected by a loss of filtration capacity, an increase of additive consumption, and a fall in the recoverable sugar calculated according to Schneider. A correct equation to estimate the molasses sugar to be obtained from frostdamaged beet still does not exist.