Abstract
Wash-free rice is intended for use in an emergency. To evaluate the characteristics with storage, commercial wash-free rice, which had been prepared by a dry method, was stored at 20°C and,60%RH for up to 9 months, and the quality changes in the raw rice and cooked rice were investigated in comparison with those of common milled rice. The value of fat acidity was increased by storage, especially after 3 months. This was most marked in the outer parts, which were collected by grinding common milled rice to 4% and wash-free rice to 3.5%. This fat oxidation was delayed in the wash-free rice. The soaking solution of the wash-free rice contained higher levels of solid matter, free amino acids, and sugar than that of the common milled rice. The results of a sensory analysis show that the cooked wash-free rice was inferior in transparency, glossiness, whiteness and so on. After 5months of storage, the flavor and taste were significantly unfavorable too. During storage, the stickiness and adhesiveness of cooked rice from both the wash-free and common milled origins, as determined by a Texturometer, had decreased. The cooked rice also developed a yellowish tinge, by which the b-value determined by a color-difference meter tended to increase.
