Introducing Pistacia khinjuk (Kolkhoung) Fruit Hull Oil as a Vegetable Oil with Special Chemical Composition and Unique Oxidative Stability

Abstract

The chemical and qualitative characteristics of P. khinjuk hull oil (PKHO), P. atlantica hull oil (PAHO), and Sesamum indicume L. cv. Dezful seed oil (SISO) were compared. The high values of wax and tocopherol compounds and low values of the saponification number of PKHO were interesting. PKHO was also unique due to its high content of tocotrienols (92.6% of total tocol compounds). Oxidation stability data showed that PKHO was the most stable oil against lipid oxidation, followed by PAHO and SISO. The conjugated diene hydroperoxides increase during heat treatment (8 h) at 170°C for PKHO, PAHO, and SISO and were 18.41, 25.28, and 300.66%, respectively. Moreover, the carbonyl value was significantly increased at the lowest speed for PKHO, followed by PAHO and SISO. During heat treatment, there was no difference between PKHO and PAHO concerning total polar compounds, whereas the parameter showed a linear increase for SISO. The antioxidative activity of PKHO at low concentration (0.0099%) in olive oil was also almost equal to that of TBHQ (100 ppm).