Extrusion cooking gelatinises starch, and denatures protein-
aceous materials as they are plasticised and restructured to
create new shapes and varied textures (Harper and Tribehorn
1992
). The effect of extrusion on antioxidant capacity of corn
extrudates fortified with Chinese yams (Chiu et al.
2011
), and
the effect of storage on rice flour
–
fish coextrudates with
respect to sorption isotherm, vitamin A and total tocopherols
and lipid oxidation profile (Shankar et al.
2010
) has been
recently reported. Flavours and colours, if required, are
generally added after extrusion processing. This adds one
step in the processing line. Coloured extrudates would be a
welcome addition by both processors as well as consumers.
We have previously evaluated anthocyanin as a pre-extrusion
colour for rice flour (Durge et al.
2011
). Dehghan-Shoar et al.
(
2011
) investigated on extraction of lycopene from extruded
products containing 10% tomato skin.