Tofu samples were cut into pieces of weight 5–8 g.
Each sample was placed in a crucible, vacuum dried at
105 C for 4 h. Then quickly take the samples out of the
dryer and put them into a desiccator for 30 min. The
difference between the initial weight and final dry weight
was used to calculate the water content (AOAC, 1984).
The shelf life of tofu was determined by performing a
sensory test to samples stored at 4 C refrigerator. A
group of five experienced panelists was asked to examine
the samples to see if there was noticeable change in color
or flavor, or microbial growth on sample surface. The
shelf life was reported as the days in storage that sig-
nificant microbial growth on samples was found by the
panelists. To measure the gel strength, tofu was cut into
samples with a thickness of 15 mm. Each sample was
placed on the anvil of a Sun Rheometer (model CR-300,
Japan). A spherical probe (5 mm diameter) traveled
downward (6 cm/min) to penetrate the samples. The
breaking force (g) and breaking strain (mm) were re-
corded. The gel strength (g mm) was calculated as the
product of breaking force and breaking strain.