Black sesame (Sesamum indicum L.) seeds extracts by CO2 supercritical fluid extraction: Isotherms of global yield, kinetics data, total fatty acids, phytosterols and neuroprotective effects

Abstract In Brazilian folk medicine, black sesame ( Sesamum indicum L.) seeds are one of the most important ingredients present in the tea used to treat stroke victims. Nevertheless, extracts by supercritical extraction of black sesame seeds have not been applied in neuroprotection studies. The objective of this work was to investigate some process variables of supercritical fluid extraction in black sesame to generate extracts applicable in stroke research. Two isothermal (40 and 60 °C) were explored, combined with pressures that ranged from 200 to 400 bar, at a constant mass flow rate of 5.9 × 10 −5  kg/s. The global yields ranged from 37 to 53% in dry basis. The highest mass yield was obtained at 60 °C and 400 bar. The fatty acid composition comprised a high unsaturated/saturated ratio. Chromatographic analysis of phytosterol content in the high global yield extract revealed higher amounts of β-sitosterol + sitostanol, cholesterol, campesterol + campestanol + 24-methylene cholesterol, Δ-5 avenasterol and stigmasterol, while lower levels of Δ-5,24 stigmastadienol, brassicasterol, clerosterol + Δ-5-23 stigmastadienol, Δ-7 avenasterol, eritrodiol and Δ-7 stigmasterol were present in the black sesame extract. Overall extraction curves from the supercritical fluid extraction (SFE) in lower and higher global yields (200 and 400 bar at 60 °C) fitted the Tan and Liou, Goto et al. and Sovova models. These models presented the best residual sum of squares values. Pilot experiments suggest that black sesame extract is neuroprotective following endothelin-1-induced focal ischemia into the motor cortex of adult male rat, observing a decrease in leukocyte infiltration in the group treated with SFE of black sesame seeds when compared with control group.