Protein composition and technological properties of milk whey concentrates

Abstract

Aim. To study the composition of commercial samples of whey protein concentrates obtained by the method of ultrafi ltration from cheese whey and present on the Ukrainian market. Methods. Determination of nitrogen- containing fractions by the Kjeldahl method, protein composition – by electrophoresis in polyacrylamide gel, amino acid composition – on the amino acid analyzer, functional and technological properties of concen- trates, characterizing their ability to participate in surface phenomena, – by conventional methods. Results. It was determined that the protein fractions of the investigated industrial samples are mainly β-globulin and α-lactalbumin, the total content of which is from 90 to 96 %. It was noted that the concentrates with a higher content of total protein have a smaller proportion of non-protein nitrogen and caseins. It was determined that the amino acid content of dry cheese whey is lower than that of the concentrates. It was established that the increase in protein content in concentrates up to 70–80 % leads to a signifi cant increase in the foam-forming, water-retaining, fat-retaining and emulsifying capacities of concentrates in comparison with the milk whey. It was noted that the indicators characterizing the technological properties of the investigated commercial sam- ples of concentrates with the same protein content may vary within 10–15 %. Conclusions. It was established that the investigated commercial samples of whey protein concentrates have an increased biological value and improved functional and technological properties in comparison with dry cheese whey, which allows using them in the formulations of other food products. To obtain fi nal products with stable characteristics, it is neces- sary to evaluate the technological properties of concentrates entering the enterprise as part of implementing the activities of the product quality management system.