【摘要】 <正> 引言稻谷在保管期內,因(一)貯藏條件, (二)其他生物(害蟲和微生物),及(三)糧粒本身的生命活動等三者相互作用,逐漸發生品質變化,降低食用及種用價值。左右着這種變化的條件:第一,是稻谷的含水量;其次,是隨着季候變化的更多还原

【Abstract】 From Sept. 1954 to Nov. 1955. investigations were made on the safe storage of rice grains of different moisture contenst. "Tu-Sien" one variety of Indian rice with moisture contents of 12.06%, 13.04%, 14.09%, and 15.05%, and "Hou-Geng" another variety of Japanese rice with moisture contents of 12.66%, 13.5%, 14.9%, and 15.50% were stored separately with respect to variety and moisture contempt in the bins with a capacity of 29,000 Kg. each. The changes of temperature and moisture contents of the grains were recorded every one or two weeks respectively. The kinds and amounts of insects and microbes and their actions were examined frequently; analysis of the contents of total nigrogen, soluble nitrogen, fat acidity, soluble sugar and vitamin B₁ and test of the seed viability were also carried out every month during the period of experiment. The results thus obtained are summarized in the following paragraph:1. The temperature of the rice grains in the bin decreased from Sept. 1954 in accordance with the changes of air temperature and reached to the minimum at the end of Feb. 1955, thereafter it gradually rose up. However, there was no difference occurred in the temperature changes among the bins with rice grains of various moisture contents until the early in the June 1955. At that time the air temperature was already over 25℃. and approached to 30℃.. The grain temperature in each bin showed a great difference, those with a moisture content below 13.5% had a temperature similar to the air, but various degrees of spontaneous heating were occurred in the bins with grains of higher moisture content.2. From the start of this study to Feb. 1955, the moisture content of rice grains in every bin has been increased because changes of air temperature and humidity, subsequently it dropped down. In general the extent of variation of the moisture content is greater in Hou-Geng than in Tu-Sien, in the grains with lower than in the higher moisture content. However, the moisture content of the grains when equilibrium with the humidity of the air was above 13.5% all over the year.3. 51 species of the microbes have been isolated from the rice grains of both Hou-Geng and Tu-Sien. All of which except one species of bacteria were mould. The frequencies of occurance of the microbes were much more in Hou-Geng （511）than in Tu-Sien （406）. The amount of mould spores per gram of rice grains reached to the maximum during summer period. In general it is higher in the grains with higher moisture content and in Hou-Geng than in Tu-Sien.4. There are certain relationships among the temperature, moisture content of grains and the development of the destructive insects, the higher the moisture content is, the more will be the insects. Since there were more insects than could be controlled therefore fumigations with chloropicrin were made in early July 1955.5. There was no significant diffecence in the percentage of germination from Sept. 1954 to May 1955. The grains with higher moisture content suffered markedly by losses of germinability due to the fumigations with chloropicrin. But the grains with moisture contents below 13%, however, have recovered their germinabillty to certain degrees two months later.6. Results of chemical analysis of the samples taken from the bins throughout the year indicated that the changes on the total nitrogen and salt soluble nitrogen contents is negligible. There is a good ovidence, however, that the fat acidity increases and the soluble sugar and vitamin B₁ content decrease during storage.7. From the results obtained, it indicates, that the safe moisture content of rice grains in the bins of the customary warehouse at lower Yangtze valley s,hould be around 13.5%. Although the grains with moisture content of 15% may keep in a fair condition throughout the winter period, but spontaneous heating would be easily to occur during summer months.8. Acooring to the results we obtained and in the light of other literatures the importance of the safe moisture content of rice grains, is discussed.更多还原