| Summary: | Characteristics of tofu with higher aw (0.89 to 0.90) and protein levels of 8% or more, made
tofu to be a suitable medium for bacterial growth. This leads to out to be very easy to damage
due to bacterial contamination. Contamination of bacteria commonly found in the tofu
because of contamination in the process making of tofu. Source contamination can come out
from the raw material, during the process of making tofu and hygienic sanitation level during
processing. Generally, this study aims to determine the level of contamination of Escherichia
coli, Staphylococcus aureus, Bacillus cereus and spore-forming bacteria in the process of
making tofu and study the properties of heat resistance of each isolate. Phases of of the study
started with the isolation and identification and then quantitative analysis of Escherichia coli,
Staphylococcus aureus, Bacillus cereus and spore-forming bacteria in the tofu process from
raw materials to end product, tofu, is water and soybean, slurry, soymilk cooking, curd, whey
and tofu. Isolates originating from the cooking process and the coagulation process for testing
the heat resistance (D value and Z value). D and Z values calculated using linear regression.
Escherichia coli found in the water, soybeans, soybean slurry, curd and tofu, the number 101
-102 CFU/g. Escherichia coli GMP isolate have D60�C=4,83 min and the value of Z = 22.73�C.
Staphylococcus aureus found in soybeans and curd, the number of 101 CFU/g . The
Staphylococcus aureus GMP 4 isolate, have D60�C =2.72 min and the value of Z = 18.87�C.
The Staphylococcus aureus GMP 6 isolate, have D60�C =2.54 min and the value of Z =
18.18�C. Bacillus cereus found in the water, soybean, soybean slurry, soymilk cooking, curd
and tofu , the number 102 -103 CFU/g. Bacillus cereus vegetative cells SK 2 have D60�C =5.43
min and the value of Z = 22.72�C. Bacillus cereus vegetative cells SK 4 have D60�C =5.95 min
and the value of Z = 22.22�C. Spore-forming bacteria found in water , soybean, soybean
slurry from the grinding process, the process cooking of soymilk, the process of clotting,
whey and tofu, with a number of 102 CFU/g .
Keywords: tofu, Escherichia coli, Staphylococcue aureus, Bacillus cereus, a spore forming
bacteria, heat resistance
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