Researching of utilization of camel chymosin in the production and ripening of beyaz peyni̇r and comparison with calf chymosin

This study is divided in two stages. The main objective was to investigated the utilization of camel chymosin as a coagulant in the production of Beyaz peynir and comparison with calf chymosin. In the first stage, the effect of pH on the coagulation of milk used in the manufacture of Beyaz Peynir using camel chymosine was determined. For that reason, cheese milk were coagulated in three different pHs (6.6, 6.4 and 6.2). The produced cheeses were ripened for 75 days and then analysed for their composition, proteolysis and texture. The pHs of coagulation caused significant differences in the rennet coagulation time of milk and gross chemical composition of cheeses. Lower level of proteolysis was observed in the cheeses coagulated at pH 6.2. Hardness of the cheeses and residual coagulant activity was also influenced by the coagulation pHs of milk. In conclusion of this part of study, pH 6.2 was seleced as the best coagulation pH for Beyaz peynir. In the second stage, the two coagulants were compared in terms of salt concentrations (9%, 12%, 14%). The cheeses coagulated by camel chymosin were influenced by salt concentrations when compared to the cheeses produced using calf rennet. Use of different concentrations of salt significantly influenced urea-PAGE, RP-UPLC peptide profiles, pH 4.6-soluble nitrogen fractions and hardness of the cheeses. These differences were demonstrated using principal components analysis for casein degradation and peptide profiles of the cheeses. Higher levels of residual coagulants were observed in cheeses using with calf rennet and also its brine was contained higher levels of coagulant activity. Otherwise, the cheese made by camel chymosin contained lower level of residual coagulant activity than the cheeses made using calf chymosin. In conclusion, using camel chymosin and 12% brine solution showed similar results with the cheeses made using calf chymosin and 14% brine solution. Keywords: White cheese, camel chymosin, proteolysis, salt, brine.