The shelled fruit of rice is called caryopsis (brown rice), which consists of cortex, endosperm and embryo. Brown rice cortex includes pericarp, seed coat, exoendosperm and aleurone layer. In the process of rice milling, most of the husk of brown rice will be stripped into rice bran, so the husk of brown rice is always called chaff layer. Embryo is located in the lower abdomen of brown rice and connected with endosperm, but the connection is not very close, so it is easy to peel off with rice bran when milling. Endosperm is the main component of brown rice, and its weight accounts for more than 90% of the whole brown rice, which is the rice we usually eat.

The rice we eat is mainly endosperm (that is, transparent part), which is made by grinding brown rice. In the process of grinding, a part of the embryo (that is, the white opaque part) of brown rice is peeled off, and a part remains on it. That's why you see some completely transparent and some translucent. ~