Linear discriminant analysis as a tool to assess the effects of irradiation treatment and storage time on antioxidant activity of Castanea sativa Miller skins and fruits.

Due to the high levels of chestnuts production in Portugal, and the economical importance of their industrial derivatives, it is essential to find technologies that increase chestnuts shelf-life. This kind of study must always be associated with the evaluation of the effects of those technologies in the final quality of the product. Herein, the effects of gamma irradiation and storage time in antioxidant potential of chestnut (Castanea sativa Miller) fruits and skins obtained in Trás-os-Montes, Northeast Portugal, was evaluated for the fist time. The irradiations were performed in a 60Co experimental equipment, for 1 h (0.27  0.04 kGy) and 2 h (0.54  0.04 kGy). Bioactive compounds (phenolics and flavonoids) and DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, reducing power and inhibition of -carotene bleaching capacity were determined at 0, 30 and 60 days of storage at 4ºC. The results were evaluated through Linear Discriminant Analysis (LDA) to evaluate if the differences induce by irradiation and storage could act as discriminant variables regarding antioxidant potential and bioactive compounds contents.