γ-Oryzanol, tocol and mineral compositions in different grain fractions of giant embryo rice mutants

Abstract

BACKGROUND: Rice embryo is concentrated with lipid, protein and some bioactive chemicals. Two rice mutants IR64-GE and TNG71-GE (M7 generation) were characterised by an enlarged embryo compared with their wild types. In the present study, distributions of protein, lipid, total phenolics, ?-oryzanol, tocols and some essential minerals in these two giant embryo mutants and their respective normal embryo wild types IR64 and TNG71 were compared. RESULTS: The embryodry weights of giant embryo mutants IR64-GE and TNG71-GE were 0.92 and 1.32mgper seed respectively. These values were higher than those of their respective normal embryo genotypes (0.50 and 0.62 mgper seed). Large variations in protein, lipid, phenolic, gamma-oryzanol, tocol and minerals levels were found between mutant and wild-type pairs. The brown rice of TNG71-GE had higher total. -oryzanol (average of 24% increase) and total tocol (average of 75% increase) levels than TNG71, IR64 and IR64-GE. CONCLUSION: The embryo and bran parts of giant embryo mutant TNG71-GE were found to be good sources of vitamin E and. -oryzanol. Therefore it could be used to produce high-value by-products from milled embryo and bran parts and as a genetic resource for rice improvement programmes. TNG71-GE can also be used as a nutrient-fortified rice cultivar. (C) 2011 Society of Chemical Industry