Extraction of Phospholipids From Crude Rapeseed Oil by n-Hexane/Alcohol System: Effects of Solvent Composition on...

Rapeseed oil contains endogenous phospholipids (PLs) and other minor bioactive components, but conventional PL extraction methods commonly rely on chloroform-based solvent systems that are unfavorable for green and food-related applications. In this study, n-hexane/methanol and n-hexane/ethanol extraction systems were evaluated as alternatives to the conventional Folch procedure for PL extraction from crude rapeseed oil. The effects of solvent type and water content on degumming performance, PL subclass composition, oil quality, and structural characteristics of the recovered PLs were systematically investigated. Compared with the Folch procedure, the n-hexane/ethanol systems showed significantly improved PL extraction efficiency while maintaining high PL purity. Among the tested conditions, n-hexane/ethanol (1:1, v/v) containing 7% water (HE7) gave the best overall performance, yielding 91.18% PLs with 96.54% purity, 90.18% oil recovery, and an undetectable phosphorus content. Compositional analysis showed that the recovered PL fractions were mainly composed of phosphatidylcholine (PC) and phosphatidylethanolamine (PE), although the subclass distribution varied with the extraction system. FTIR, polarized light microscopy, and scanning electron microscopy confirmed that structurally intact PL-rich fractions were obtained and that their microstructure depended on extraction conditions. Degumming substantially reduced acid value, but also altered oxidative stability and the retention of endogenous minor components in the oil phase. Correlation and hierarchical clustering analyses further identified HE7 as the most balanced green extraction condition. HE7 represents a promising and more sustainable alternative to the conventional Folch procedure for PL recovery from crude rapeseed oil.