Value-added processing with respect to rice milling has
traditionally treated the rice bran layer as a homogenous
material that contains significant concentrations of highvalue
components. Rice bran fractionation allows for the
selective use of portions of the bran layer and is advantageous
for two reasons: (1) bran fractions contain much
higher concentrations of components of interest with
respect to the overall bran layer average, and (2) less bran Oryzanol and protein concentrations were found to be
the highest in the outer portion of the rice bran layer,
while RBS concentration was found to be the highest in
the inner portion of the bran layer. Vitamin E concentration
was highest at the 10-second milling time, but no significant
difference existed between milling times within a
variety.
This laboratory scale study illustrates the potential for
selectively fractionating the bran layer to obtain small,
nutrient rich bran samples. Additional studies involving
model development for industrial scale-up are warranted;
our hypothesis is that rice bran collected at the first milling
break will be oryzanol and protein rich. Future work
in this area could include rice variety development and
process optimization with a focus on increasing the concentration
of high value components, and retaining the
bio-activity of high-value components at the industrial
scale. Taken collectively, research indicates that milling
times, kernel-thickness, bran fraction, rice variety, and
environmental conditions can be used to select for high
concentrations of specific phytochemicals in rice bran,
including several not quantified in this study, e.g. rice
bran oil and waxes.
needs to be processed to obtain components of interest.
This research is important to the biological engineering
community because it uses bioprocess engineering methods
to isolate health related components of interest in a
biological product