Anti- and pro-oxidant water soluble activity of Cichorium genus vegetables and effect of thermal treatment

Both the pro- and antiradical water soluble activity, toward DPPH¥, ROO¥, OH¥ radicals found in seven
diet vegetables belonging to the Cichorium genus, and the effects of boiling, freezing, and freezedrying
on such activities were investigated. The vegetables were three red cultivars of Cichorium
intybus var. silvestre from three different areas of production, that is, chicory from Chioggia, Treviso,
and Verona, C. intybus var. foliosum (Belgian chicory), C. endivia var. latifolium (escarole), C. endivia
var. crispum (“crispa”), and a hybrid vegetable obtained by the cross between C. intybus var. silvestre
and C. endivia var. latifolium (chicory from Castelfranco). The juices obtained by simple centrifugation
of vegetables operating at 2 or 25 °C and submitted to the thermal technological treatments were
assessed for antiradical activity using the DPPH¥ assay, the linoleic acid-â-carotene system, and
the deoxyribose assay. In all three assays used, each vegetable juice was shown to possess antiradical
activity; there was a significant level in the C. endivia and the Belgian chicories and higher levels in
the red C. intybus vegetables and the hybrid vegetable. All juice behaviors in the linoleic acid-â-
carotene system indicate that they also contain a thermally unstable component, which in a cold
medium promptly promoted and accelerated linoleic acid peroxidation, therefore masking the presence
of any thermally stable antiperoxyl radical components. The presence of these components, which
efficiently protect linoleic acid from peroxidation, can be singled out only after inactivation by heating,
or separation by dialysis, of the pro-oxidant components. Dialysis fractions showed that the prooxidant
component has MW > 50000 Da and that the juices contain a number of antioxidant
components which contribute to their antiradical activity.