Production of glycerylphosphorylcholine-enriched defatted egg yolk powder through integrated enzymatic and supercritical CO2 processing

Abstract

Glycerylphosphorylcholine (GPC) is a bioactive compound with potential health benefits, including cognitive support and cellular metabolism enhancement. In this study, GPC-enriched defatted egg yolk powder was prepared using an innovative combination of dual-enzyme hydrolysis and supercritical CO₂ extraction. Optimized conditions achieved a high conversion rate of phosphatidylcholine (PC) (89.9 %). Key parameters included a 2:1 enzyme ratio (phospholipase A₁ to lysophospholipase), 161 U/mL enzyme concentration, 3-h reaction time, 55 °C temperature, and a 1:2 yolk-to-water ratio. Furthermore, under the same conditions, the content of GPC reached 0.374 g per 10 g of egg yolk powder. Supercritical CO₂ extraction increased the protein content and GPC content of the egg yolk powder from 29.9 % to 68.68 % and 3.74 %–7.75 % while reducing the lipid content and cholesterol content from 50.1 % to 6.75 % and 4.21 %–0.16 %. Accelerated storage tests revealed that as the storage time increased, the changes in the particle size and secondary oxidation products of EYP161-SYE were less pronounced, which correlated with improved solubility and storage stability. These findings highlight the potential of this approach for producing high-value, stable GPC-enriched egg yolk powder for applications in food and nutraceuticals.