Oats contain a range of functional ingredients; these are concentrated to a
greater or lesser extent in different parts of the kernel. Dry milling of
oats using roller milling offers the opportunity to produce, at a lower pro
cessing cost, fractions enriched in antioxidant activity.
Oats were roller milled and the stocks separated by size using sieving; the
fractions were analysed for compositional differences. A clear difference
was seen between the larger particles, which were richer in bran and its as
sociated components. and the smaller, starch-rich particles: with a natural
cut-off point occuring at 420 mu m. This established the feasibility of us
ing dry milling and sieving oats to yield enriched fractions.
Oats (cv. Gerald) from a variety of sources were dehulled then milled once
and fractionated to yield a bran-rich fraction (>420 mu m) and a starch-ric
h fraction (<420 mu m). Polar lipid extracts were derived from these fracti
ons and their antioxidant activity measured by chemiluminescence (CL). Bran
-rich fractions had significantly higher antioxidant activity than the corr
esponding starch-rich fraction and appealed to have a more potent populatio
n of phenolic antioxidant compounds. (C) 2000 Academic Press.