Studies on the Suitability for Storage of High Moisture Rough Rice

Abstract

1. The moisture content of individual paddy on the matured panicles had a wide distribution from 15% to 29%. In the panicles from a sunny environment, the moisture content had a parallel relation with the stage of maturity; in the rainy environment, the hanging grains on standing plants had high moisture content. The frequency of moisture class differed with weather conditions (Fig.1. 2).2. When the fresh rough rice was dried by heated air, the high moisture grains were dried rapidly, and the mean moisture content decreased in relation to narrowing of its distribution. The different moisture of paddy was equilibrated rapidly in the initial period, and slowly in the later period during storage, but they had unequal moisture among individual grains after 10 days (Fig.3. 4).3. The relation between the individual grain moisture and its term until deterioration was only a few days at above 23%, the grains of 19%-23% were deteriorated after 15 days, and the moisture content of grains which changed to spot or opaque within 2 months was above 19% (Table 2).4. The humidity around the grains equalized with the high moisture of the paddy swiftly; the paddy of 19.3% mean moisture content was equalized at 90% of relative humidity (RH), of 20% at 93% of RH, of 22.3% at 97% of RH, of 24.7% and of 30% was saturated humidity (Fig.5).5. The moisture content of paddy which prevented deterioration in the temporary storage was less than 19%. As the newly threshed paddy has a wide deviation in individual grain moisture, if the mean moisture content is as little as 19%, the storage of paddy which narrows the deviation by forced heated air is preferable.