Extraction and Identification of Phytosterols in Manketti (Schinziophyton rautanenii) Nut Oil

Phytosterols of manketti (Schinziophyton rautanenii) nut oil extracted by Soxhlet, mechanical shaking using hexane, screw press and supercritical carbon dioxide, were analyzed by gas chromatography with flame ionization detection and identified by gas chromatography–mass spectrometry. The presence of several phytosterols (campesterol, stigmasterol, β-sitosterol, ∆⁵-avenasterol, 22-dihydrospinasterol and ∆⁷-avenasterol) previously reported in manketti oil, was confirmed. In addition, another fourteen phytosterols (lanosterol, ∆⁵,²³-stigmastadienol, ∆⁷-campesterol, clerosterol, obtusifoliol, ∆⁵,²⁴⁽²⁵⁾-stigmastadienol, α-amyrin, gramisterol, cycloeucalenol, cycloartenol, stigmasta-8,24-dienol-3-β-ol, 28-methylobtusifoliol, 24-methylenecycloartenol and citrostadienol) were identified. The phytosterols, β-sitosterol, ∆⁵-avenasterol and campesterol, had the highest concentrations in oils extracted by all the methods, whereas stigmasterol and cycloartenol were abundant in oils extracted by mechanical shaking and supercritical carbon dioxide. Total phytosterols and the quantities of individual phytosterols differed significantly (p ≤ 0.05) in oils from the four extraction methods. Mechanical shaking extracted the highest levels of total sterols (22,100 mg/100 g oil), followed by supercritical fluid extraction (9,550 mg/100 g oil). Screw press and Soxhlet extracted oils contained the lowest levels of total sterols, 3,810 mg/100 g oil and 3,350 mg/100 g oil, respectively.