Abstract: First, monochromatic near infrared light in a wavelength range of 700 nm-1100 nm from the slit of the near infrared apparatus 1 is applied to a reference ceramic plate through the optical fiber 7 to measure a transmitted light intensity of the ceramic plate which is a reference material for spectrum measurement. Next, in place of the ceramic plate, the test tube 4 containing a liquid sample of which the temperature has been adjusted at a predetermined temperature by a water bath and the like is inserted into the housing portion 5. The transmitted light intensity of the liquid sample is then measured using the same procedure as above. A so-called near infrared absorption spectrum in which absorbance has been plotted against wavelengths is displayed on the screen of the computer 2. Information about each object characteristic is extracted from the spectrum data using a calibration equation.

Abstract: The invention provides a diploid or higher polyploid, practical baker's yeast with good frozen dough resistance. This is produced through mating with one or more NTH1 gene-disrupted, haploid yeasts as produced through gene manipulation of disrupting the NTH1 gene in a haploid yeast of which the diploid is practical baker's yeast. The reduction in the trehalose content of the yeast is significantly prevented even when used in frozen dough, and the frozen dough containing the yeast is well resistant to long-term freezing and storage.