Abstract:
The main objective of this dissertation work was to perform comparative study on the
milkclotting characteristics of crude kiwifruit (Actinidia deliciosa) and ginger (Zingiber
officinale) proteases in soft cheesemaking. The effect of crude kiwifruit and ginger
protease on physicochemical and microbial characteristics of soft cheese prepared were
examined. Temperature and pH of the milk on milk clotting activity (MCA) and time of
coagulation (TOC) were optimized by response surface methodology (RSM). The protease
activity and protein concentration of the crude kiwifruit and ginger protease were also
measured in optimized conditions. Finally, the cheese prepared by using crude kiwifruit
and ginger protease were compared with rennet cheese for physicochemical and microbial
properties.
Numerical optimization study revealed that optimum condition of milk clotting for
kiwifruit and ginger were found to be 61°C (at pH 6.5) and 55°C (at pH 5.5) respectively.
The optimized TOC and MCA for crude kiwifruit protease were found to be 120.513 s and
492.630 units respectively. Similarly, TOC and MCA for crude ginger protease were
1591.667 s and 241.988 units respectively. The physico-chemical analysis showed that
there was non-significant difference (P>0.05) in protein content among cheeses made using
rennet and crude plant proteases while significant difference (P<0.05) was observed in
moisture, fat, ash, calcium, acidity, pH and cheese yield. Microbiological analysis showed
the absence of coliform in all three cheeses. Similarly, significant difference (P<0.05) was
observed in the total plate count (TPC) of all three samples while non-significant
difference (P>0.05) was found in the count of yeast and mold
Description:
A dissertation submitted to the Department of Food Technology, Central Campus of
Technology, Tribhuvan University, in partial fulfilment of the requirements for the
degree of B. Tech. in Food Technology
