Changes in nutraceutical lipid components of rice at different degrees of milling

Abstract

The concentrations of several nutraceutical lipid components [tocol (i.e. tocopherol + tocotrienol) phytosterol, gamma-oryzanol, octacosanol, and squalene] in milled rice and brown rice were determined. The lipid content decreased significantly (P < 0.05) as the degree of milling increased, as did the total tocol content. Significant differences (p < 0.05) were observed in the relative percentages of alpha-tocopherol, alpha-tocotrienol, and gamma-tocotrienol in brown rice and milled rice. beta-Sitosterol was the most abundant sterol, representing 50-56% of the total sterol content of all samples analyzed. There were no significant differences in the relative percentages of the sterol isomers as the degree of milling increased. The concentrations of gamma-oryzanol, squalene, and octacosanol in rice decreased significantly (p < 0.05) as the degree of milling increased.