OPTIMIZATION OF CRUDE PAPAYA (Carica papaya) PROTEASE IN CREAM CHEESE PREPARATION BY RESPONSE SURFACE METHODOLOGY

Abstract

The effect of papaya latex as crude papaya protease on physicochemical, microbial and sensorial characteristics of cream cheese prepared were examined. Enzyme concentration, pH of milk and temperature of milk on milk clotting activity were optimized by surface response methodology. Also, the protease activity of the crude enzyme was also measured using optimized conditions. Finally, the cheese prepared by using crude papaya protease was compared with that prepared using rennet and commercial papain for physicochemical, microbial and sensorial properties. Numerical optimization study revealed maximum milk clotting activity at pH 6.5, temperature 70℃ and enzyme concentration 1% (1 ml/1000 ml milk) using papaya protease as coagulant. Protein, ash and calcium showed no significant (p>0.05) difference among the cheeses made using different coagulants. However, significantly (p<0.05) higher levels of moisture and ash, and lower levels of fat were observed in the cheese produced by papaya protease compared to that made using rennet. Papaya protease significantly enhanced the spreadability of cheese while the other sensory properties were similar to the control except aftertaste. Microbiologically, all samples were not significantly different and were free of coliforms. However, the presence of TPC and yeasts and molds was found. The results revealed that the papaya latex as crude papaya protease may have potential application for the manufacture of cream cheese and further could be utilized as a milk coagulant in cheese making.