2.2.4. Oil-Soy Extraction. The oil-soy extraction method was performed in triplicate according to the procedure presented by Sachindra and Mahendrakar [11]. The extraction yield was evaluated using soybean oil as solvent. The method consisted of mixing 2.5 g cell biomass with 20 mL vegetable oil in a 250 mL flask (light protected), submitted to hot plates with 2 h agitation period at room temperature. Further, the oil extracts were recovered by cellulose filtration (0.22 m) and the extraction yield and content of astaxanthin was quantified by HPLC analysis.