All elements of the pistachio tree are considered raw pistachio by-products. The soft hull makes
up the majority of these by-products. It contains proteins, fats, minerals, vitamins, phenolics
contents (TPC), and antioxidants. Early smiling pistachios are one of the most important sources
of pistachio contamination with afatoxin in the garden and processing stages. The present study
aimed to evaluate pistachio hull essential oil (EO) composition, and antioxidant and antimicrobial
properties under in vitro conditions. TPC, antioxidant, and antimicrobial activity were measured
using the Folin–Ciocalteu reagent, 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging
method, and serial dilution titration method, respectively. A gas chromatography system with a mass
spectrometer (GC-MS) was utilized to determine the chemical components of the EO. The fndings
revealed that the quantity of TPC and anti-radical activity in IC50 were 245.43 mg gallic acid/mL and
206.32 µL/L, respectively. The free radical absorption activity of DPPH (%) increased with EO content.
The inhibitory activity of EO on Staphylococcus aureus and Bacillus subtilis was much lower than
that of streptomycin and penicillin. Aspergillus favus was efectively inhibited by pistachio hull EO,
comparable to fuconazole. The results obtained from GC-MS showed that the major compounds in
pistachio hull essential oil include α-pinene (47.36%), terpinolene (10.57%), limonene (9.13%), and
L-bornyl acetate (8.57%). antioxidant components and can be employed as a natural antimicrobial and antioxidant in food
systems.