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, vulgaris extracts composition We fractionated samples of total lipids extracts obtained from C. vulgaris under double extraction (ScCO 2 followed by ScCO 2 + ethanol 10% as co solvent added at t = 210 min) into NL, GL, and PPL, by the SPE technique (Fig. 8). It can be seen that during the first stage of double extraction that NL represented 70.2 ± 2.5% of the obtained extracts when using only ScCO 2 as solvent

, Moreover, the yield of extracted GL and PPL was relatively low (6.7 and 3.5%, respectively), whereas almost 35.8 ± 0.9% of the total NL originally contained in C. vulgaris were extracted. The addition of ethanol to the stabilized extraction (at t = 210 min) significantly increased the NL, PPL, and GL extraction yield. Almost 72.9 ± 1.3% of total NL, 26.4 ± 1.5% of total PPL, and 26.1 ± 1.2% of total GL were obtained by the end of extraction (Fig. 8B). These results may be due to the increase in the polarity of the medium after the injection of ethanol which may boost the extraction of both polar, ± 0.3%), whereas GL represented 25.3 ± 1.3% of the extracted material (Fig. 8A)

, Our results competed with Moradi Kheibari and Ahmadzadeh [33] who studied NL extraction from C. vulgaris using ScCO 2 with a disruption step and a higher pressure. Furthermore, the NL extraction yield was higher than that obtained by double extraction, 10% v/v) at the beginning of the extraction did not give the same results as those of the double extraction

, Using double extraction, the lipid molecules remaining in the matrix from the first stage become highly viscous and form agglomer ates that hindered their diffusion during the second step [34]. This could limit the extraction of NL remaining in the biomass which could not pass through the non disintegrated cell wall as shown by micro scopic observation

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