2.1. Rice samples
Two rice cultivars were selected for this study on the basis of
their pericarp colors. Sample rice 1 is a medium grain rice colored
with a brown bran layer; sample rice 2 is a long grain rice colored
with a dark bran layer. They were all cultivated in the 2009e2010
growing season in the South of China, and are abbreviated as LBR
(light brown rice) and DBR (dark brown rice), respectively in this
study. After the removal of hulls, aliquots of the two brown rice
samples (2 kg) were stored at 4 C and 37 C in sealed glass bottles,
and subsamples were withdrawn at different time intervals during
the six month storage period. Prior to analysis, the brown rice was
ground using a Cyclone Sample Mill (UDY Corporation, Fort Collins,
CO, USA) through a 0.5 mm sieve screen. All the analyses were
performed in triplicate.