Fed batch fermentation was carried out for the dextransucrase enzyme production from Leuconostoc mesenteroides and the production was scale-up using oxygen transfer criteriuom. It was found that in 5 L vessel fermentation capacity, the best agitation speed was 225 min-1 and aeration rate was 0.15 vvm, obtaining dextransucrase activity of 127 DSU/mL.. The maximum enzyme production velocity coincide with the maximum growth velocity between 6 and 7 h of fermentation, which confirmed that dextransucrase production was associated with microbial growth. High enzyme yields were achieved during scale up based on oxygen transfer rate.

Flour and gluten extracts have been fractionated by gel filtration on Sephades G-loo, and starch gel electrophoresis has been used to investigate the degree of separation of the various protein components obtained. Although the method does not result in the isolation of individual proteins, it does separate them into certain groups, and offers possibilities for the study of protein interactions under various conditions in flours and doughs.

The use of ultrafiltration to fractionate dextran solutions in order to obtain fractions for the synthesis of dextran derivatives was investigated. Several experiments were carried out in two available commercial ultrafilters. The operation was evaluated by the recovery yield and process time. Dextran solutions can be fractionated being concentrated up to 9 fold in a PM30, but no more than double in a PM5 hollow fibre membrane cartridge.