Investigation effects of extracted compounds from shell and cluster of pistachio nut on the inactivation of free radicals

Essential oils (EOs) are known for uses in various fields such as perfume, cosmetic, pharmaceutical and food industries. Agricultural wastes are among the resources of EOs that produced and disposed of in large quantities annually. Hence, in this study, for the first time, EOs available from pistachio fruit [fruit pistachio shells (FPS) and fruit pistachio cluster (FPC)] were used to the extraction of EOs. The Clevenger device and distilled water were used to extract EOs. The amount of total phenolic compounds (TPC) by Folin-ciocalteu reagent and the radical scavenging ability (RSA%) of FPS and FPC extracted by the soaking method were also measured. The RSA% of EOs and extracts in the presence of DPPH free radicals was evaluated by the IC(50) index. Chemical composition of EOs detected by mass spectrometric gas chromatography. Notwithstanding amounts of extraction efficiency by water in the soaking method from FPS and FPC was 4.6% and 3.2% respectively, EOs extraction efficiency from FPC and FPS was 2.10% and 0.13% respectively. TPC in FPS and FPC was 958.38 and 796.25 mgGA/100g dry material respectively. The amount of IC(50) of FPS was 3760.69 ppm and near to RSA% of BHT (2354.36 ppm). Statistical difference was observed between the RSA of EOs and positive control antioxidant (P < 0.05). The RSA of antioxidant extracts and TPC showed positively correlated. The major compounds identified in FPS were the D-limonene, α-thujene and terpinolene, abundance respectively, and the major components of FPC were α-thujene and α-pinene, abundance respectively.