Investigation on the effect of preserving epicarp during drying on physico-chemical, organoleptic and quanitative properties of pistachio kernel (Owhadi cultivar)

Pistachio is one of the most important strategic agricultural products of Iran which is extremely important from different economic and social aspects. Paying more attention to maintaining the quality of the crop after harvest is also important to other crops for higher yields. In this study, in order to evaluate the quality, physicochemical and organoleptic properties, pistachio cultivar Ohadi was prepared and dried with epicarp (outer skin) and conventional method (without epicarp). In the usual method, with water floatation, Sinkers (underwater) and floaters pistachios were isolated and treated as two separate treatments. At the end of the first, second and third month after pistachio drying, samples were taken from each treatment and randomized complete block design of physical properties (total weight, kernel weight, shell skin weight, moisture content and shell skin color). Chemical properties (fat percentage, carbohydrate, protein, fiber, ash, dry matter, percentage of phenolic compounds and oil peroxide number), organoleptic properties (taste, odor, appearance and texture) it placed. The results showed that processed with epicarp method and conventional method had no significant difference in physical and organoleptic properties at the 5% level of Duncan Multiple Range Test. There were no differences in chemical properties between percentages of carbohydrate, protein, fiber, ash and dry matter. But the percentage of fat was lower than the treated samples sinkers (under water). The presence of higher phenol content and lower peroxide content showed an increase in the quality of processed pistachios with epicarp. While this method saves water and energy consumption and reduces environmental hazards caused by waste and wastewater from conventional processing, it can improve the antimicrobial, antifungal and antioxidant properties of phenolic compounds present in our skin for producing healthy pistachios.