Chemical composition and antioxidant activity of cured chestnuts from three sweet chestnut (Castanea sativa Mill.) ecotypes from Italy

The composition of commercial marrons from three Italian sweet chestnut ecotypes, 'Marrone di Castel del Rio', 'Marrone di Marradi', and 'Marrone di Valle Castellana', from Emilia Romagna, Tuscany and Abruzzi region, respectively, was studied during two consecutive years (2003-2004). Results showed a great variability of moisture content. The average content in nutrients (expressed in dry weight) was in the normal range for this type of product, but compositional data showed great variability as a function both of variety and of harvest year. Marrone di Valle Castellana showed the highest content in sucrose and fibre. Marrone di Castel del Rio presented the highest protein content, probably due to the schistose soil of the region. Marrons of Valle Castellana presented the lowest calcium content as a result of the specific nature of the soil in the area of origin. Linear discriminant analysis achieved high recognition percentages for the classification of marrons according to the ecotype, with 100% recognition for each of the three ecotypes. The content in antioxidant compounds (ascorbic acid and total polyphenols) and the antioxidant activity of the nuts were investigated. All the ecotypes showed a low polyphenol content but were high in ascorbic acid level, which accounted for a discrete antioxidant activity (3.02 - 3.11 TEACg(f.w.)(-1)) of the nuts.