In all vegetable oils, the composition can vary depending on the cultivar, environmental conditions, harvesting, and processing.
[1][2] The intense coloration, very characteristic of pistachio oil, is due to the content of chromophores, particularly chlorophyll and carotenoids.
The total carotenoid content has been reported to be 15 - 61 mg/kg, with the main components in order of concentration being lutein, β-carotene, neoxanthin, luteoxanthin, and violaxanthin.
[3] The high concentration of monounsaturated and polyunsaturated fatty acids makes it susceptible to auto-oxidation, which can be delayed by naturally present tocopherols or added antioxidants.
Other minor components of pistachio oil found in some studies include squalene, phenols with aldehydes, terpenes, and alcohols that give it a characteristic aromatic note.