Effect of Sun-Drying and Roasting on Pistachio Quality and Health Benefits

Since processing may affect the quality and benefits of foods, a study was conducted to compare some properties of fresh, sun-dried (constant water content of 4%) and oven-roasted (130 °C for 25 min) pistachio nuts of two cultivars. Carotenoid, iron, copper, manganese, and total saturated, total unsaturated, palmitic and linolenic fatty acids showed no statistical difference (P ≤ 0.05) among the samples. Comparing ‘Akbari’ cultivar, ‘Ahmadaghaei’ cultivar had less anthocyanin and less palmitoleic acid. Drying and roasting reduced antioxidant activity, flavonoid content, and arachidonic acid content, while increased kernel firmness, malondialdehyde and hydrogen peroxide. Chlorophyll content was higher in dried and roasted than fresh status in both cultivars. Stearic acid had a stable content in ‘Ahmadaghaei’, but increased by drying and roasting in ‘Akbari’. Oleic acid increased by drying and roasting in ‘Ahmadaghaei’. In ‘Akbari’, oleic acid first decreased by drying and then increased to the initial level by roasting. Linoleic acid decreased by drying and roasting in ‘Ahmadaghaei’. In ‘Akbari’, it revealed an increasing trend by drying, but again decreased to the initial content after roasting. It was concluded that the condition which was used in this experiment for drying and roasting the pistachios was not harmful and had some advantages which lead to better storage of pistachios.