Method of producing nutritionally enriched rice

A method of producing a nutritionally enriched rice which comprises: a harvesting step (S1) wherein fresh unhulled rice (2) usable as the starting material is harvested from a field; a nutritionally enriching step (S2) wherein the fresh unhulled rice (2), which has an average water content at a predetermined level, i.e., 20% by weight or more, is heated in a microwave heater and then kept hot in a warmer for a predetermined period of time to give a nutritionally enriched unhulled rice (3); and a drying, hulling and milling step (S3) wherein the nutritionally enriched unhulled rice (3) is dried until the average water content thereof attains a level suitable for prolonged storage, hulled to remove the hull and then milled to remove the embryo and the bran layer to thereby give a nutritionally enriched white rice (4) which contains a large amount of γ-butyric acid in the albumen.