In this work, COSMO-SAC was used to calculate infinite dilution activity coefficients (γ^∞) of carotenoids in CO₂+ethanol mixtures as a theoretical approach to evaluate the effect of solvent composition on solute solubility. In an experimental approach, a central composite design was employed to evaluate the use of supercritical mixtures of CO₂+ethanol to extract chlorophylls and carotenoids from the microalga Chlorella sorokiniana. The carotenoid profiles of extracts were fully evaluated, and the optimal conditions for the extraction of chlorophyll a, chlorophyll b, carotenes, lutein, zeaxanthin and violaxanthin were differentiated. Extraction temperature, pressure and the composition of the solvent proved to be relevant factors, as the experimental conditions rendered fundamentally different extraction results. The presence of ethanol proved to be essential for the efficient extraction of chlorophylls and to substantially improve the recovery of carotenoids. Scanning electron microscopy (SEM) was used to evaluate cell integrity, and indicated that the increase of pressure may have positively affected the extraction of compounds by causing disruption of the particles. The theoretical approach in this work was able to corroborate experimental results for the extraction of carotenoids from C. sorokiniana, reinforcing the hypothesis that carotenoids are extracted from the microalgal biomass as aggregates, and showing that COSMO-SAC is an important tool for the selection of the supercritical solvent.

在这项工作中，COSMO-SAC 用于计算CO ₂ +乙醇混合物中类胡萝卜素的无限稀释活度系数 (γ ^∞ )，作为评估溶剂组成对溶质溶解度影响的理论方法。在实验方法中，采用中心复合设计来评估使用 CO ₂ +乙醇的超临界混合物从微藻Chlorella sorokiniana 中提取叶绿素和类胡萝卜素。充分评估了提取物的类胡萝卜素谱，确定了叶绿素a、叶绿素b提取的最佳条件、胡萝卜素、叶黄素、玉米黄质和紫黄质被区分。萃取温度、压力和溶剂组成被证明是相关因素，因为实验条件呈现出根本不同的萃取结果。乙醇的存在被证明对于有效提取叶绿素和显着提高类胡萝卜素的回收率是必不可少的。扫描电子显微镜 (SEM) 用于评估细胞完整性，并表明压力的增加可能通过导致颗粒破裂对化合物的提取产生积极影响。这项工作中的理论方法能够证实从C. sorokiniana 中提取类胡萝卜素的实验结果，加强了类胡萝卜素作为聚集体从微藻生物质中提取的假设，并表明 COSMO-SAC 是选择超临界溶剂的重要工具。