As intended, when the sum of daily temperature of the sake
mash (Tsum) was higher, MB staining ratio was also higher. The
increase in MB staining ratio may have been because of an increase
in ethanol concentration and the fermentation temperature
immediately prior to completion of the fermentation process. The
sake yeast is more sensitive to environmental stress than wild-type
yeast and produces a higher concentration of ethanol. This happens
because of a defect in the environmental stress responses that
cause the organism to die (13,14). The absorbance at 260 nm (A260)
increased along with the increase in Tsum, which was primarily
caused by leakage of the yeast cell content into the sake mash (15).
The correlation coefficient between the MB staining ratio and A260