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

The concentrations of several nutraceutical lipid components [tocol (i.e. tocopherol + tocotrienol) phytosterol, γ-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 α-tocopherol, α-tocotrienol, and γ-tocotrienol in brown rice and milled rice. β-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 γ-oryzanol, squalene, and octacosanol in rice decreased significantly (p < 0.05) as the degree of milling increased.