The residual Mine and citric acid contents are very similar in their importance to the treatment of thin juice. Investigations were started on the formation of citric acid during the growth of beet and on the behaviour of this acid diuring the juice purification process.
It was found that from the beginning of July till the beet harvest the citric acid content in the roots drops from 900 mg / 100 g of dry matter to about 600 mg / 100 g. During campain the citric acid: content in the beet is commonly constant for an area. In the same period the citric acid content of the leaves arises from about 950 mg/100 g of dry matter to 1,800 mg/100 g. This significant difference in the content of citric acid might be an indicator of the maturity of beet for processing.
Besides this the development of the raffinose content and the distribution of some interesting substances, in roots and leaves, was investigated.
When processing beets the greatest proportion of citric acid is precipitated in the main defecation. In the filtrate from the main defecation about 250 mg of citric acid / 100 g of sugar (polarization) remain dissolved. This amount is independent on conditions of main defecation. 80 to 130 mg of citrate / 100 g of sugar (polarization) were found in the juice after first carbonatation and 30 to 80 mg of citrate / 100 g of sugar (polarization) din the thin juice prior to evaporation, The quantity of citrate dissolved in the thin juice depends on the CaO-content at the second carbonatation. It is therefore recommended to add 0.15 to 0.20 % of CaO on juice in the second carbonatation to reach a final citrate content of about 40 mg / 100 g of sugar (polarization) tin the thin juice. With this final citrate content technological difficulties are avoided.
Proceedings: CITS 1971
pdf download: CITS1971-35-46.pdf