Influence of Partially Purify Enzyme in Experimental Cheddar Cheese Production

Abstract

Calf rennet is the main enzyme component has been widely used as a milk clotting enzyme for cheese making. The high price of traditional rennets and ethical consideration associated with their use promoted the new rennet substitute. The cheeses were studied to determined difference chemical, biochemical and sensory characteristics throughout of 2 months of ripening. The cheese yield produced from commercial enzyme was (p<0.05) higher than cheese produce from kesinai enzymes. Both cheese samples were compositionally alike except for moisture, protein contents and pH. In both cheese moisture contents declined (p<0.05) with ripening period while pH was increased with ripening time. Total nitrogen (TN), non protein nitrogen (NPN) and non casein nitrogen (NCN) were (p<0.05) higher in whey of cheese made with kesinai enzyme than cheese made with commercial enzyme. The amount of NPN and NCN found in cheese made with kesinai enzyme was (p<0.001) higher than in cheese made with commercial enzyme. NPN and NCN values were increased (p<0.001) throughout the ripening period in both cheeses. Cheese made with commercial enzyme exhibited slightly higher level of free amino acids than cheese made with kesinai enzyme. But free fatty acids compositions have shown similar changes in both types of cheese thought the ripened time. Textual characteristics such as hardness, gumminess and chewiness increased in both types of cheese during early stage of ripening and decrease gradually at end of ripening whereas springiness, adhesiveness and cohesiveness were showed similar changes in both cheeses during the ripened period. The principal component analysis (PCA) of electronic nose sensor data has been studied using “Z”nose. The results indicated that, the presence of 7 volatile (aroma) common compounds in both cheeses. PCA analysis was performed to discriminate the cheeses with their ripening time.