Supercritical CO 2 extraction of residual oil from pressed sesame seed cake: Optimization and its physicochemical properties

Abstract

Supercritical CO2 extraction was selected to extract oil from pressed sesame seed cake. The effect of extraction parameters on the quantity and quality of extracted oil, namely temperature (40–60℃), pressure (175–225 bar) and time (1–5 hr), was studied. By using response surface methodology with the Box–Behnken design, the optimal extraction condition was achieved at 50℃, 220 bar, and 5 hr and provided 29.80% db of the oil yield. The extracted oil contained sesamin (225.79 mg/100 g cake), sesamolin (75.57 mg/100 g cake), tocopherols (7.03 mg/100 g cake) and Folin–Ciocalteu reducing capacity (29.11 mg GAE/100 g cake). Main fatty acids observed in the extracted oil were linoleic acid (36.18%–45.38%) and oleic acid (31.84%–39.40%). The experimental results indicated that supercritical CO2 extraction could be a viable technique to extract the residual oil from pressed sesame seed cake. Practical applications It is obvious that supercritical CO2 extraction technique could be used to recover a residual oil efficiently from pressed sesame seed cake. The extracted oil was obtained at the optimum extraction temperature of 50℃, extraction pressure of 220 bar and extraction time of 5 hr. The extracted oil samples had high scavenging activity containing bioactive compounds including tocopherols, sesamin, and sesamolin. The fatty acid compositions of extracted oil from pressed sesame seed cake by supercritical CO2 extraction were linoleic acid and oleic acid. It was implied that the unsaturated fatty acid of the sesame oil was more than the saturated fatty acid. On the basis of this result, the extracted oil from pressed sesame seed cake can be considered as potential source of linoleic acid and oleic acid and alternative source of edible vegetable oil.