Trigonella foenum‐graecum L. Seed Oil Obtained by Supercritical CO2 Extraction

Abstract

AbstractSupercritical CO2 extraction (SC‐CO2) of fenugreek (Trigonella foenum‐graecum L.) seed oil and its chemical composition and antioxidant activity were investigated. A central composite design combined with response surface methodology was used to study extraction conditions including pressure, temperature, and time. The optimum extraction conditions were 28.5 MPa extraction pressure, 41 °C extraction temperature, and 118 min extraction time, where 3.78 % yield was predicted. Fenugreek seed oil extracted under optimum conditions by SC‐CO2 was mainly composed of 28.3 % C18:3, 33.45 % C18:2, 9.89 % C16, 8.1 % C18:1, 3.7 % C18, 0.71 % C20, and 0.61 % C22. The fenugreek oil was rich in unsaturated fatty acids (nearly 70 % of the total fatty acids), and polyunsaturated fatty acids accounted for 61.42 % (mass percentage) of the total amount. The 2,2‐diphenyl‐1‐picrylhydrazyl radical‐scavenging activity increased from 12.5 to 88.4 % when the concentration was increased from 1 to 12 mg/ml. The reducing power of the seed oil was concentration‐dependent. The antioxidant activity of the supercritical fluid extraction extract was superior to those obtained by Soxhlet extraction.