Composition of the NF concentrates of curds whey

The work is devoted to the research of the composition of curds whey concentrates obtained by nanofiltration (NF concentrates). Based on an analysis of published data on changes in the composition and properties of curds whey in the course of nanofiltration process possibility to apply the NF-concentrates for the production of various products was substantiated. Brief results of the studies carried out by some authors aimed at investigation of possible application of nanofiltration for the processing of different types of the dairy raw materials (NF processing) are given. The object of the study was to curds whey with titratable acidity 70 °T, which has been subjected to concentration on a pilot nanofiltration plant. The process was conducted in three stages: nanofiltration, diafiltration and deep diafiltration. Constituents of the original whey and the concentrate received were analyzed. The results were used to calculate the loss of the curds whey constituents during NF-processing. It was established that the main losses occur in mineral salts and lactic acid. Decreasing the amount of mineral salts in the concentrates is due to ions of Na and K. Divalent ions in the process of nanofiltration actually are not removed. Loss of total solids is 7-9 %. Loss of total solids during the diafiltration increased slightly at the expense of deeper demineralization and neutralization of curds whey. Removal of organic acids, mainly the lactic acid during processing of NF-curds whey constitutes 28-29 % that is insuf ficient for wide spread application of curds whey in food products. The authors made conclusion about necessity to neutralize excess amount of lactic acid in the NF concentrates.

curds whey, nanofiltration, demineralization, diafiltration, neutralization