Autor(es):
Carocho, Márcio 
; Antonio, Amilcar L. ; Kałuska, Iwona ; Bento, Albino ; Ferreira, Isabel C.F.R.
Data: 2012
Identificador Persistente: http://hdl.handle.net/10198/7822
Origem: Biblioteca Digital do IPB
Assunto(s): Chestnuts; E-beam; Irradiation; Antioxidant potential
Descrição
Chestnut fruits (Castanea sativa Mill.) are widely consumed all over the world,
and have been studied in terms of nutritional value and also for their antioxidant potential. In
Europe, Portugal is one of the leading producers of this nut, and its conservation is essential.
Irradiation might be an alternative conservation method, since methyl bromide, a widely used
fumigant, was prohibited as post-harvest technique by the European Union in 2010 due to its
toxicity. The alternatives, hot water dip treatment among others, still present some
disadvantages. Food treatment with radiation is environment friendly, poses no threat to
consumers and is nutritionally adequate. The present study reports the effect of e-beam
radiation (doses of 0, 0.5, 1 and 3 kGy, being 0 the control, non-irradiated) on the antioxidant
potential of Portuguese chestnuts, as an ongoing project with previous results for gamma
radiation. The antioxidant activity was evaluated through 2,2-diphenyl-1-pycryl-hydrazyl
(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. Total phenolics and flavonoids were performed by
spectrophotometric assays. Irradiated samples seemed to preserve total phenolics content (but
not flavonoids) and revealed higher antioxidant activity (lower EC50 values) than the control
samples. The most indicated dose to maintain antioxidants content, and to increase
antioxidant activity was 1 kGy.
