The aim of the present study was to evaluate the effect of refrigerated storage temperature on the proteolysis in cow's milk Kashkaval cheese. The Kashkaval samples were stored for 12 months at four different temperature regimes - cooled at 4,0 ± 1,0 °C, cooled at 1.0 ± 1.0 °C, superchilled at -7,5 ± 0,5 °C and frozen at -18.0 ± 1.0 °C. The proteolysis in cheese samples was evaluated by determining the non-casein nitrogen (NCN/TN), non-protein nitrogen (NPN/TN) as a percentage of total nitrogen and content of free amino groups. It was found that the storage temperature had a significant impact on the hydrolysis of cheese paracasein. Complete inhibition of the proteolysis was established only in frozen stored Kashkaval. Slight, but statistically significant (P<0,05) increase in the NCN/TN values indicating for retarded proteolysis in samples stored at -7,5 ± 0,5 °C was established. The increasing of the storage temperatures results in increased NCN/TN, NPN/TN values and free amino groups content. The highest proteolysis rate was observed at the refrigeration temperatures of 4.0 ± 1.0 °C. The samples stored at this temperature regime had the highest values of both high molecular weight protein fractions (NCN/TN) and products of deep proteolysis (NPN/TN and free amino groups).

Kashkaval is a hard cheese produced in Eastern Europe and consumed after ripening. The influence of ripening temperature (9±1°C, 11±1°C and 13±1°C) of cow's milk Kashkaval cheese on its physicochemical, microbiological and sensory characteristics was studied. For the ripening period no statistically significant differences (P>0.05) in the indicators dry matter, fat content, salt and protein were found. A slight decrease in active acidity was observed during the maturation process which tendency was more pronounced in the experimental samples ripened at higher temperatures (13.0±1.0°C). It was found that lowering the ripening temperature of Kashkaval cheese was accompanied by a prolongation of the lag phase in the development of lactic acid microflora. A significantly higher amount of lactic acid microorganisms (P<0.05) in cheese samples matured at 13±1° C was established. The chosen temperature regime of maturation did not affect the number of psychrotrophic microorganisms (P>0.05). The absence of unwanted side microflora in fresh cheese was established, which was an important prerequisite for the normal course of the maturing processes and the formation of a characteristic sensory profile of the cheese. Kashkaval cheese ripened at 13±1°C for 45 days was characterized by the highest overall sensory score comparable to Kashkaval cheese ripened at 9±1°C and 11±1°C for 60 days. The obtained results demonstrated that the higher ripening regime could be successfully used to reduce production costs without changing the specific physicochemical, microbiological and sensory characteristics of Kashkaval cheese from cow milk.