Evaluating the fatty acid composition of the oil from fruit hulls of two Pistacia species growing wild in Iran

Abstract

ingredients. They are round to oval, somewhat flat, and 0.5–0.7 cm and 0.3–0.5 cm in diameter in P. atlantica and P. khinjuk, respectively. Their wooden hard shells are covered with a rather dry hull, which could be easily removed by pressing between fingers. The color of these soft hulls is dark green [3] and their oil contents are 30% (P. atlantica) and 40% (P. khinjuk). The fatty acid compositions of the oils from the fruits of P. atlantica and P. khinjuk indicate that the nutritional value of P. atlantica fruit oil is better than that of P. khinjuk [4]. The amount of linoleic acid, which is essential in human diet, in P. atlantica fruit oil is greater than that in P. khinjuk. Moreover, essential fatty acids have been shown to reduce the level of cholesterol in the blood. They prevent cardivascular diseases better than any other oil [5, 6]. In this investigation, the fatty acid composition of P. atlantica hull (PAH) and P. khinjuk hull (PKH) oils was studied. The fatty acid compositions of these oils were analyzed by GC, and the results are given in Table 1. The major fatty acid components characterized in the oil were as follow: oleic acid (52.03–52.12%), palmitic acid (22.55–23.4%), palmitoleic acid (7.74–14.05 %), linoleic acid (5.35–12.02%), stearic acid (2.39–3%), and linolenic acid (1.16–1.5%), but negligible amounts of margaric acid (0.05–0.4%), margaroleic acid (0.2–0.24%), and gadoleic acid (0.25–0.76%) were identified in the fatty acid composition of these oils. Fatty acid (FA) components representing about 99.58–99.63% of total oil were characterized. The amounts of saturated (SFA), monounsaturated (MUFA), and polyunsaturated fatty acids (PUFA) in the studied oils were found to be 25.84–25.95, 60.22–67.17, and 6.51–13.52%, respectively. The main fatty acid found in PAH and PKH oils was oleic acid, and there was no significant difference in amounts of it between the two studied oils. The amounts of palmitic acid and linolenic acid in PAH and PKH oils were statistically the same, too. The percentage of linoleic acid in PKH oil was more than that in PAH oil, but the palmitoleic acid and stearic acid contents in PKH oil were lower than those in PAH oil.