Antioxidant Activity and Phenolic Compounds Profile of Pistachio Skins (Pistacia vera L., cultivars Kallehghuchi and Ohadi)

Background: Pistachio with scientific name Pistacia vera L., a native plant in Asia, is a member of Anacardiaceae family. Pistachio nuts and skins are known as a rich source of phenolic compounds with antioxidant, anti-inflammatory and antimicrobial properties.Objectives: In current study industrial production of phenolic compounds with antioxidant activity was investigated because of high mass production of Pistachio skin in Iran.Method: The extraction of two pistachio cultivars, namely Kallehghuchi and Ohadi were carried out by using two methods (maceration and ultrasonic extraction) and four solvents (acetone ۷۰%, ethanol ۵۰%, methanol ۵۰% and water). Antioxidant properties of pistachio skins were determined by three methods (Folin-Ciocalteu colorimetric method, DPPH assay, TLC/DPPH analysis).Results: The results showed that the highest content of total phenolic compounds were measured by ultrasonic and maceration methods related to Ohadi and Kallehghuchi in acetone solvents ۱۷.۴ ± ۰.۰۴ and ۱۷.۲۶ ± ۰.۱ mg/g DW respectively. The highest antioxidant activity in were measured by ultrasonic and maceration methods related to Ohadi in acetone and water solvents IC۵۰ = ۰.۰۵۷ ± ۰.۰۰۱ and ۰.۰۵۹ ± ۰.۰۰۲ μg/mL respectively. By TLC/DPPH analysis, gallic acid, ۴-hydroxy-۳, ۵-dimethoxy benzoic acid, tannic acid and some unidentified compounds were determined. By HPLC analysis, gallic acid, coumaric acid, cinnamic acid, ۴-hydroxy-cinnamic acid and ۴-hydroxy benzoic acid were determined.Conclusion: In conclusion, this study clarifies some special biochemical characteristics of pistachio skins. Therefore, according to results of the study pistachio skins could be successfully used in food and pharmaceutical industries.

Keywords:

Pistacia vera L. , Antioxidant activity , Extraction , Phenol compounds