From the filtered juice of homogenized sugar beets, the enzymes polyphenoloxidase (PPO), peroxidase as well as alpha- and beta-galactosidase in catalytically active form were adsorbed on a clay bed mineral (Na-bentonite). Peroxidase was concentrated 500-fold on the bentonite and, by changing the pH value, was almost completely desorbed in technical quality with a 100-fold increase in specific activity. PPO was concentrated in the bentonite up to 5000-fold and desorbed with anhydrous glycerine with a 20-fold increase in specific activity. Beta-galactosidase was not amenable to desorption, but retained almost all its enzymatic activity in the adsorbed state. The likewise not desorbable alpha-galactosidase was isolated from the bentonite adsorption, by means of successive gel and affinity chromatography, on immobilized lectin in technical quality (1500- to 3600-fold increase in specific activity).

Campaign figures - beet production and yields - East-West comparison - weather conditions and molasses analyses - apparent storage losses - sugar losses - extraction tower - advances in pressed pulp dry matter - pH profile of extraction acidification by mineral acid or infection - pulp pressing additives and thin-layer high-pressure pressing - ammonia stripping - minimum requirements for sugar factory effluents - quality of sugar beets - soda consumption - pilot trials relating to beet quality - technical school evaporation and crystallization apparatus - plate evaporator performance - new evaporating crystallizers with a new vapour compressor in the Swiss Aarberg sugar factory - determination of oxygen in steam - magma flow behaviour - process control engineering: practical experiences with the high-frequency probe - continuous centrifugals