Supercritical fluid extraction of high-value natural products from buttermilk analyzed by a dynamic extraction model

Supercritical CO₂ with/without ethanol extraction of buttermilk was carried out at 50°C and various pressure and ethanol concentration conditions. Extracts were analyzed by TLC-FID and found to be mainly composed of triglycerides, obtained from both CO₂ and CO₂ with ethanol extractions, and polar lipids such phosphatidylcholine and sphingomyelin, obtained only from CO₂ with ethanol extraction. A dynamic extraction model was applied to the obtained data and could describe extraction curves of solutes in the buttermilk. Solubility of triglycerides in supercritical CO₂ obtained in this work was almost coincident with values in the literature. Although the solubilities of both phosphatidyl choline and sphingomyelin were not available in the literature because of the highly variable components, they could be estimated by applying the extraction model to the obtained extraction results.