Sustainable recovery of phospholipid-enriched polar lipids from scallop processing wastes for multifunctional application.

This study developed sustainable extraction strategies for obtaining value-added scallop oil (SO) from processing waste using conventional solvents and subcritical solvents as dimethyl ether (SCDME), butane (SCB), and butane combined with ethanol (SCB-EtOH). Phospholipid (PL)-enriched polar lipids were further prepared from extracted scallop oil by ternary biphasic separation method, and their antioxidant and emulsifying properties were also evaluated. The results showed that solvent polarity critically influenced both extraction yield and compositional characteristics, including PL content, fatty acid profiles, sterols, and vitamins. Strong-polar ethanol and subcritical extraction methods showed superior total lipid recovery compared to conventional solvents, with both ethanol and SCBME exhibiting particular efficacy for polar PL extraction (194.94 and 194.52 mg/g, respectively). While SCB alone produced low-PL oil, its combination with ethanol significantly increased PL content (168.83 mg/g), and also oil yield (15.67 %). Additionally, it was also found that DHA content correlated positively with PL levels, and subcritical extraction better preserved heat-sensitive components like DHA and vitamins than conventional methods. The optimized hexane-ethanol-water (1:3:1) system achieved exceptional PL recovery (96.26 %). Subsequent characterization revealed significantly enhanced antioxidant capacity compared to ethanol-extracted scallop oil and neutral lipid fraction, along with emulsifying properties and storage stability comparable to those of commercial emulsifiers.