Chestnuts (Castanea sativa Mill.) are widely consumed all over the world, and have
been recently studied for their antioxidant potential. The present study reports the effect
of e-beam and gamma radiation (doses of 0, 0.5, 1 and 3 kGy) on the antioxidant
potential of Portuguese chestnuts. Irradiation might be an alternative preservation
method, since Methyl Bromide, a widely used fumigant, was banished by the European
Union in 2010 due to its toxicity. The antioxidant activity was evaluated through 2,2-
diphenyl-1-pycrylhydrazyl (DPPH) free radical scavenging activity assay, reducing
power by the Ferricyanide/Prussian blue assay, and lipid peroxidation inhibition by β-
carotene/linoleate and thiobarbituric acid reactive substances (TBARS) assays. The
analysis of total phenolics and flavonoids was performed by spectrophotometric assays.
Irradiated samples preserved total phenolics content (but not flavonoids) and revealed
higher antioxidant activity (lower EC50 values) than the control samples. The most
indicated doses to maintain antioxidants content, and to increase antioxidant activity
were 1 kGy and 3 kGy for electron beam and gamma radiation, respectively.
