Abstract:
The main objective of the present study was extraction, purification and utilization of
proteolytic enzyme from the latex of Calotropis gigante in fresh cheese making. The crude
extract was subjected to TPP in varying optimization parameters of ammonium salt
concentration (30-80%), ratio of t-butanol to crude extract (1;0.5-1:2) and the extraction pH
(4-9). Both intermediate phase and aqueous phase were analyzed using milk clotting activity,
protein content and caseinolytic activity for maximum activity recovery (%) and purification
fold. Furthermore, the optimum temperature and pH of milk in the cheesemaking, for
maximum and minimum time of coagulation (TOC), were determined by response surface
methodology. The physicochemical properties of prepared cheese were compared with
rennet cheese.
For the highest activity recovery and purification fold, the optimum condition parameters
for TPP were found to be 60% ammonium sulphate precipitation, 1:1.25 ratio of crude
extract to t-butanol (v/v) and extraction pH 6. Numerical optimization study revealed that
the optimum temperature and pH for milk clotting in cheesemaking was found to be 55°C
and pH 6 respectively. The optimized TOC and MCA were 12.91 s and 2779.65 units
respectively. The analysis of rennet cheese and aank protease coagulated cheese revealed no
significant difference (P>0.05) in fat, protein and ash content. There was also no significant
difference in yield of both cheeses.
Description:
A dissertation submitted to the Department of Food Technology, Central Campus of
Technology, Tribhuvan University, in partial fulfillment of the requirements for the
degree of B. Tech. in Food Technology
