Refined phosphatidylcholine from soybean lecithin: Purification, molecular species identification, and antioxidant activity evaluation

High-purity phosphatidylcholine (PC) finds wide applications in various fields including food, healthcare products, pharmaceuticals, feed, and cosmetics, due to its emulsifying properties, chemical stability, and biological activity‌. This study developed a novel one-step purification protocol utilizing macroporous resin column chromatography for high-purity PC (>95 %) from soybean lecithin, with comparative analysis of molecular speciation and bioactivity against yolk-PC. Adsorption isotherm analysis revealed better conformity with the Langmuir model (R 2 > 0.98) than the Freundlich model, indicative of monolayer adsorption mechanisms, while kinetic studies showed optimal fitting with the Pseudo-second-order model (R 2 > 0.99), suggesting multi-active sites involving in the adsorption process. Exceeding 95 % PC purity can be attained by one-step column chromatography method utilizing ADS-21 and NAK-2, with corresponding yield of 77.66 % and 63 %, respectively. Liquid chromatography-electrospray ionization quadrupole time-of-flight mass spectrometry (LC-ESI-QToF-MS) revealed distinct molecular species in purified soybean-derived PC (dominant C18:2/C18:2 species) compared to yolk-derived PC (prevalent C16:0/C18:1 species). Both purified soybean-PC and yolk-PC showed minimal impact on DPPH free radical scavenging and xanthine oxidase inhibitory activities as under 400 μg/mL in vitro. Overall, these findings offer valuable insights for efficiently purifying high-purity PC from soybean lecithin, distinguish molecular species and antioxidant activity of soybean and yolk-PC. • ADS-21 and NKA-2 have the highest adsorption capacity for phosphatidylcholine (PC) among twenty macroporous resins. • Adsorption behavior of ADS-21 and NKA-2 was well described by Langmuir isotherm and Pseudo-second-order in kinetics model. • Purity of ≥95 % PC was obtained by ADS-21 column chromatogryhy with yield of 77.66 % or by NKA-2 with the yield of 63 %. • Comparative analysis revealed significant diversity in molecular species of soybean-derived PC and yolk-derived PC.