Effect of the electrodialysis treatment temperature on the microflora of skim milk permeate

The article presents analysis of the effect of electrodialysis, which was carried out at the temperatures 15, 22 and 30 °C on the microbiological parameters of the secondary milk raw materials with a different mass fraction of dry substances. After four hours of electrodialysis at the temperatures of 15 °C and 22 °C the total number of the mesophilic aerobic and facultative anaerobic microorganisms of natural permeate did not change significantly from the initial level of 5,2-6,2 lg N, and at 30 °C it increased by 3,2 %. In the enriched permeate, no significant changes in total count of the psychrophilic microorganisms were observed. Initial contamination with psychrophilic and thermophilic microflora in natural and the condensed permeate varies from 4,4 to 5,5 lg N. After electrodialysis of both types of the permeate at 15 and 22 °C small changes in the psychrophilic and thermophilic microflora were observed. At 30 °C there was an increase in psychrophilic microorganisms by 3,1 %, and by 5,2 % in thermophilic microorganisms. The number of sporeforming mesophilic aerobic and facultative-anaerobic microorganisms before electrodialysis varies from 2,3 to 2,7 lg N for natural and from 2,6 to 3,6 lg N for the condensed permeate. After ED-treatment at 15 °C, no significant changes in the number of sporeforming bacteria were observed in natural permeate, at 22 °C this value increases by 12,6 % and decreases slightly at 30 °C. Certain regularities for this group of microorganisms in permeate have not been established.

lactose (milk sugar) food and pharmacopeia, lactosecontaining raw materials, ultrafiltration, microbiology of the secondary milk raw materials