2.2. Sample preparation and free and bound polyphenolics and
flavonoids extraction
Two cultivars of black rice (Oryza sativa cv. Heugjinjubyeo and
O. sativa L. Heugkwangbyeo) were obtained from the Rural Development Administration, Korea. Whole black rice of the two
cultivars was milled into rice bran and endosperm using the gradual
milling system (85% milling degree). Milled samples were
passed through 80-mesh sieves and heated at 100 C for 30 min
to inactivate the endogenous lipase. Free and bound polyphenolic
compounds were extracted from the samples as described by