EXPERIENCE OF USING HYDROGEN-PEROXIDE IN EXTRACTION

The replacement of formalin with hydrogen peroxide as a bacteriostat in extraction has been investigated in an Italian sugar factory in the years 1988-1992. Periods of up to 1 week of usage of formalin at 520 g/t beet and hydrogen peroxide at 563 g/t beet were compared. Sucrose, invert sugar, fructose, glucose, nitrite, L-lactic acid and acetic acid contents, as well as pH values and color of process juices were determined. A dosage of 1,000 g of H2O2 35% (w/w) per t of beet alone has been found to give an acceptable level of bacterial activity (practically equivalent to 500 g/t beet of formalin, 35% (w/w)), but the costs of such a treatment are totally unacceptable, On the other hand, hydrogen peroxide seems to have some beneficial effects on the colour of purified juice (-300 IU420) and on the pressing of the exhausted pulp (+2% DM) in amounts as low as 350 g/t beet. For some years, an H2O2 solution was continuously added in the extractors, with formalin at intervals when necessary.