Effect of volume reduction ration on the concentration and retention factors during ultrafiltration of goat’s milk

Abstract

This experimental work aimed to study the effect of volume reduction ratio on the concentration and retention (selectivity) factors during ultrafiltration of goat’s milk with UF25-PAN polyacrylnitrile membrane. They were calculated on the basis of dry matter, totoal protein, fat and ash content in retentates and permeate at volume reduction ratios of 2 and 3. The results showed that the increase in the volume reduction ratio from 2 to 3 led to an increase in the concentration factors of dry matter - from 1.34 ± 0.05 to 1.87 ± 0.03, total proteins – from 1.70 ± 0.02 to 2.72 ± 0.06, fat – from 1.71 ± 0.03 to 2.71 ± 0.03, ash – from 1.13 ± 0.02 to 1.52 ± 0.02 (p < 0.05). At these conditions, the retention factor (selectivity) of ash increased from 37.40 ± 2.19% to 53.50 ± 2.21% (p < 0.05). There was no significant difference (p > 0.05) of the selectivity of the membrane according to the proteins when volume reduction ratio increased. The results showed that these two volume reduction ratios and this membrane could be successfully used for the production of yoghurts with improved quality making them an excellent functional food.