Fatty acid composition of oils from fruits of three Pistacia species growing in Iran

Abstract

The Pistacia genus belongs to the Anacardiaceae family and consists of 11 species. Three Pistacia species occur naturally in Iran, including Pistacia vera, Pistacia atlantica, and Pistacia khinjuk [1]. P. khinjuk and P. atlantica grow wildly and largely in the southwest and west of Iran. P. atlantica var mutica is the most popular species of P. atlantica. P. vera is a single domestic species of Pistacia genus, too. The major pistachio producers in the world are Iran, USA, Turkey, and Syria [2]. Iran, with its 350,000 ha of P. vera growing area, is indeed the greatest pistachio producer in the world. The most popular cultivar of P. vera in Iran is Ohadi (more than 60%) [3]. The oil of pistachio contains linoleic and linolenic acids that are essential in human diet. Moreover, these fatty acids have been shown to reduce the level of cholesterol in blood. They prevent cardivascular diseases better than any other oil [4, 5]. Furthermore, pistachio nut oil is also used in the cosmetic and pharmaceutical industries [6]. In this investigation, the fatty acid composition of P. vera cv ohadi (PVO), P. atlantica var. mutica (PAM), and P. khinjuk (PKH) was studied. The fruit samples of PAM and PKH were collected from fields in Marvdasht and Kazeroon in Fars Province, respectively, and those of PVO were collected in Feizabad in Khorasan Razavi Province. All samples were stored at –18C until analysis. PVO and PAM grow in mild and cool climates and PKH grows in warm regions. The fatty acid compositions of the 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 (51.46–52.12%), linoleic acid (17.44–35.85%), palmitic acid (8.5–17.82%), palmitoleic acid (1.23–5.73%), stearic acid (1.48–2.61%), and linolenic acid (0.95–1.5%), but margaric acid (0.4%), margaroleic acid (0.43%), gadoleic acid (0.76%), and erucic acid (0.88%) were only identified in the fatty acid composition of PKH oil. Fatty acid components representing about 99.51–99.73% of total oil were characterized. The amount of saturated and unsaturated fatty acids in the kernel oils were found to be 10.04–20.83% and 71.6–84.9%, respectively. The main fatty acid component found in PKH, PVO, and PAM oils was oleic acid, and no significant difference was observe for the three pistachio varieties studied. Linoleic acid was a secondary fatty acid for PVO and PAM oils, but in PKH oil, there was no significant difference between linoleic acid and palmitic acid contents. The amount of palmitic acid and palmitoleic acid was greatest for PKH oil, followed by PAM and PVO oils, respectively. The amount of stearic acid in PKH and PAM oils was statistically the same, which was greater than that in PVO oil. The linoleic acid content of PKH oil was much lower than that of PVO and PAM. The percentage of linolenic acid in the three pistachio varieties studied was approximately the same. The PKH oil was characterized by its higher palmitic and palmitoleic acids in comparison with PVO and PAM oils. Margaric, margaroleic, gadoleic, and erucic acids were also identified in the fatty acid composition of PKH oil. From the viewpoint of nutritional value, PVO is the best Pistacia species (having the highest unsaturated fatty acids especially essential fatty acids, and the lowest saturated fatty acid), followed by PAM and PKH, respectively.