COMPOSITION AND PROCESS CHARACTERISTICS DURING ULTRAFILTRATION OF WHEY FROM KASHKAVAL

Abstract

ABSTRACT Whey ultrafiltration was carried out with a UF25-PAN polyacrylnitrilic membrane with 25 kDa molecular weight cutoff at volume reduction factors (VRF) = 2, VRF = 3, VRF = 4 and VRF = 5. The values of the principal components dry matter, protein, fat, lactose and mineral substances in the retentates and permeate obtained; the relative share of protein, fat, lactose and mineral substances in the dry matter; the concentration factor (CF) values for dry matter, protein, fat, lactose and mineral substances; and the retention factor values for protein, lactose and mineral substances were established. The results obtained for the process characteristics showed that when the degree of concentration increased, the dry matter, protein, fat, lactose and mineral substance CFs, and the protein, lactose and mineral substance retention factors also increased. It was established that the retentates obtained at degree of concentration VRF = 5 contained the individual components in amounts close to those in the milk from which the whey was initially obtained. This would enable their further inclusion and reuse in cheese production. PRACTICAL APPLICATIONS Kashkaval is the most widely produced hard cheese in our country. After Bulgaria's accession to the European Union, the requirements relating to dairy enterprises increased rapidly. This led to considerable investment aimed at enhancing competitiveness and economic efficiency through better utilization of milk components, and environmental efficiency regarding wastewater purity. Ultrafiltration is a modern process which has already been put to practical use in Bulgarian dairy enterprises, mostly for milk treatment purposes. The aim of our investigation was to study the ultrafiltration possibilities for utilization of whey obtained in kashkaval production and the potential reuse of its valuable components in the manufacture of cheese and other food products.