COMPARATIVE STUDIES ON MAJOR NUTRITIONAL COMPONENTS OF RICE WITH A GIANT EMBRYO AND A NORMAL EMBRYO

Two subspecies of rice, Oryza sativa ssp. indica rice mutant II-ge1 and O. sativa ssp. japonica rice mutant XS-ge1, were characterized by an enlarged embryo compared to their wild types. Significant increases in crude lipid content; crude protein content; vitamin B1 (VB1); vitamin B2; vitamin E (VE); essential amino acids such as arginine, aspartic acid, glutamic acid, lysine and methionine and mineral elements such as Ca, Fe, Mg, K, P and Zn were detected in rice with a giant embryo (ge). The nutrients in the brown rice changed drastically after pre-germination. The dramatic nutrient enrichments were observed in the pre-germinated brown rice with a ge. The six major enhanced nutrients were γ-amino-butyric acid (GABA), lysine, Mg, VB1, VE and Ca, and the amounts were 7.3 and 4.7 times enriched for GABA, 3.4 and 3.0 times for lysine, 2.9 and 2.7 times for Mg, 2.8 and 2.5 times for VB1, 2.5 and 2.2 times for VE and 2.1 and 1.8 times for Ca, respectively, relative to those in the brown rice with a normal embryo. The results suggest that a ge can be used as a phenotypic marker for food processors to select rice enriched with certain nutritional components, and that the application of giant-embryo rice would help develop cultivars with an improved nutritional content.