Abstract
1. When rice kernel is soaked in water, water penetrates to pericarp and subsequently to aleuron layer throngh germ end, and then goes into endosperm tissue through the peripheral starch-cell layer. In this process, rice kernel absorbs water, to 20∼25 percent of its dry weight in early stage of water absorption and this amount of water is considered to be absorbed physically. 2. In the kernels which absorb water rapidly, cells of peripheral starch-cell layer adjacent to aleuron layer are small, flat and irregular in shape. This shows that the filling up of starch in these cells is rather imperfect and loose. Accordingly, the rate of physical absorption may be mainly affected by the porosity in peripheral starch-cell layer of endosperm.
