1968 Volume 9 Issue 1 Pages 23-28
The mycoflora of 219 samples of milled rice harvested in 1965 was determined. Samples in domestic channels were collected from each of the nine geographical areas of Japan. To determine the fungal flora, fifty grains of rice from each sample were plated on Peptone-glucose agar containing chloramphenicol. Fungi were found in 143 of the samples (66.3%), whereas 76 (34.7%) did not yield any fungi. Of the 143 positive samples, 119 samples (83.2%) were usually associated with one to five colonies per 50 grains. No particular relation existed between the frequency of occurrence of fungi and the geographical areas. The total number of fungal isolates was 835 involving more than 25 genera. The major genera of fungi among these isolates were Aspergillus (51.0%), Catenularia (11.0%), Penicillium (9.2%), Fusarium (4.9%) and Cladosporium (4.8%). Other genera such as Helminthosporium (4.0%), Trichoconis (2.4%), Phoma (2.4%), and Piricularia (1.1%) were frequently isolated. The comparatively low incidence of fungi suggests that most of the samples had been kept under suitable storage conditions after harvesting and handling. Aspergillus repens (67.1%) was the most prevalent among 426 isolates of Aspergillus, and Penicillium canescens series (27.3%) was the major group of Penicillium spp. but Penicillium citrinum (3.2%) and Penicillium cyclopium (2.3%) were more widely distributed in the samples than Penicillium canescens. On the basis of these results, the milled rice investigated in this study was considered to have been conditioned and handled under satisfactory conditions.
