Effects of Electron-Beam Radiation on Nutritional Parameters of Portuguese Chestnuts (Castanea sativa Mill.) uri icon

abstract

  • Chestnuts are a widely consumed fruit around the world, being Portugal the fourth biggest producer in Europe. Storage of these nuts is an important step during processing, and the most widely used fumigant was banned in the European Union under the Montreal protocol due to its toxicity. Recently, radiation has been introduced as a cheap and clean conservation method. Previous studies of our research group proved that gamma radiation had no negative effect on the nutritional value of chestnuts; in fact, storage time had a much bigger influence on the chestnut quality. In the present study, we report the effect of a less ionizing radiation, electron beam, with doses of 0, 0.5, 1, 3 and 6 kGy in the nutritional value of chestnuts (ash, energy, fatty acids, sugars and tocopherols), previously stored at 4 ºC during 0, 30 and 60 days. The storage time seemed to reduce fat and energetic values but reported a tendency for higher values of dry matter. Regarding fatty acids, there was a higher detected quantity of C20:2 in non-irradiated samples, and four fatty acids were only detected in trace quantities (C6:0; C8:0; C10:0 and C12:0). γ-tocopherol decreased during storage time but did not alter its quantity for all the radiation doses (as like α-,β- and δ-tocopherol); in fact these compounds were present in higher concentration in the irradiated samples. Sucrose and total sugars were lower in non-irradiated samples and raffinose was only detected in irradiated samples. Electron beam irradiation seems to be a suitable methodology, since the effects on chemical and nutritional composition are very low, while storage time seems to be quite important in chestnut deterioration.

publication date

  • January 2012