Application of Quaternary Ammonium Compounds and Formalin as Disinfectants in Sugar Production

Mirjana Kepec

Sugar Factory Virovitica, Matije Cupca 254, 33000 Virovitica, Croatia

Article history:
Received November 3, 1995
Accepted April 12, 1996

Key words:
quaternary ammonium compound, formalin, sugar production

Summary:
A combined disinfection with formalin and quaternary ammonium compounds was carried out in the Sugar Factory Virovitica. During the diffusion process microorganisms cause high losses of sugar. The main types of microbial flora entering the diffusers or growing during the diffusion process are as follows: aerobic sporeforming bacteria of the species Bacillus subtilis and Bacillus stearothermophilus, Clostridia as Clostridium thermosaccharolyticum and Clostridium thermohydrosulphuricum, Leuconostoc mesenteroides and yeasts, principally of the genus Saccharomyces. The metabolic products of these microorganisms are high molecular weight polysaccharides (dextrous and levons), organic acids (acetic, lactic, etc.), alcohols, carbon dioxide and hydrogen. The growth of these microorganisms can be controlled by addition of various disinfectants. Formalin is commonly used in our factories. Before the experiment with formalin and quaternary ammonium compounds, in the diffusers an optimum disinfection scheme was determined with formalin 0.03% of the mass of the beet (300 ppm) and the best results were obtained with 50% formalin consumption and by adding about 25 ppm of quaternary ammonium compounds. The efficiency of quaternary ammonium compounds against thermophylic microorganisms has been confirmed. This kind of research should be continued to further reduce formalin consumption, or to substitute formalin completely with less toxic, biodegradable biocides.