Determining the effect of nanofiltration on the nutritional and biological value of whey

The object of this study is the nutritional and biological value of whey subjected to nanofiltration treatment. The problem addressed is the insufficient efficiency of traditional methods of whey processing to increase its nutritional and biological value without losing useful components. The study found that the use of nanofiltration significantly affects the consistency of whey, which becomes thicker and more viscous. The taste and smell change from sour-milk to sweet, with pleasant whey notes. Nanofiltration leads to an increased concentration of dry matter, by 3.3 times; protein, by 3.8 times; and minerals, by 2 times. Active acidity also increases, which indicates changes in acid-alkaline balance. Analysis of the amino acid composition revealed an average increase in both essential (threonine +31.24%, leucine +31.13%, methionine +24.12%, lysine +28.65%) and non-essential amino acids (serine +69.08%, glycine +54.43%, alanine +67.36%, and aspartic acid +21.46%). The amino acid score of most essential amino acids exceeded 110% while the coefficient of variation decreased, indicating a more balanced composition. The increase in the biological value of whey to 60.4% indicates its increased nutritional value and potential as a functional ingredient in food products. The results obtained are explained by the selective permeability of nanofiltration membranes. In particular, those that retain protein substances and allow water and low-molecular components to pass through. The results have practical significance since the ability of nanofiltration to selectively separate substances enables effective processing of whey, while preserving its nutritional and biological properties