Öz
Aim of
this study was to investigate the effect of supplementary irrigation on the
total antioxidative capacity and total phenolic content of hazelnuts. Orchard
of hazelnut trees were irrigated at the different growth stages combinations.
To determine antioxidative capacity, the samples were analyzed by the
spectrophotometric assay using the stable DPPH radical. The total phenolic
content was determined by the Folin-Ciocalteu assay. The results indicated that
the total antioxidative capacity was affected by the irrigation conditions. The
hazelnut kernels and defatted hazelnut kernels from irrigated at all growth
stages showed the highest antioxidative capacity, while the lowest
antioxidative activity was observed in control (no irrigation applied). On the
contrary, the hazelnut kernel oil obtained from control induced higher
antioxidative capacity than irrigated at the first growth stage. These
spectrophotometrically measurements confirm that hazelnut kernels and their
oils contain antioxidative components having different structural properties
such as lipophilic and hydrophilic character and amounts of these compounds
were changed by irrigation conditions. In contrast, any notable change of total
phenolic content was observed in hazelnut samples, depending on the irrigation
condition.