Cereal Chem. 70:650-655   |  VIEW ARTICLE

Screening for Stable High Head Rice Yields in Rough Rice.

B. O. Juliano, C. M. Perez, and F. Cuevas-Perez. Copyright 1993 by the American Association of Cereal Chemists, Inc. 

Varietal differences in head rice yields were demonstrated by subjecting rough rice to moisture adsorption stress (soaking in 30 C water) for 1-3 hr, air-drying, and subjecting the brown rice to micromilling with a Kett Pearlest mill. An earlier method consisted of soaking brown rice in water for 5-10 min and determining the percentage of cracked grains. IR60 and IR58 were the IR nonwaxy rices most resistant to grain fissuring. The stress test is preferably done on rough rice and shade-dried to 14% moisture so that only the susceptible varieties crack. Alkali spreading value (starch gelatinization temperature) and apparent amylose content were less important than brown rice translucency in affecting head rice yield of stressed grain from the International Rice Research Institute crops. Rices grown in Palmira, Colombia, and at Beaumont, TX, in the United States differed in stressed head rice yield from those grown at the International Rice Research Institute in the Philippines.