Simultaneous texturization and extraction of phospholipids from liquid egg yolk using renewable solvents

Abstract

A simultaneous texturization and extraction of phospholipids (STEP) technique was developed to extract phospholipids (PL) from liquid egg yolk. Three solvents, 100% butanol, 80% butanol, and 95% ethanol, were tested. All solvents can texturize the liquid yolk at the same time recover the lipid with greater than 90% total lipid recovery after five sequential extractions. It is shown that 100 and 80% butanol can extract the total lipid faster (i.e., more at the earlier stage) than the ethanol, and they are more effective in extracting total yolk lipids but with little preference for PL. On the contrary, 95% ethanol has high preference for PL than for neutral lipids. PL can be enriched to 80% purity directly from liquid yolk with a total PL yield of 78% using 95% ethanol under the first stage of the STEP conditions. Therefore, this 95% ethanol solvent has a great potential to process liquid yolk into a yolk lecithin concentrate, a neutral lipid‐rich fraction, and a defatted and texturized yolk protein. The uniqueness of this study is the simultaneous texturization and the strengthening of the yolk protein network that allows the extraction of lipids without the generation of the protein fines which could greatly reduce processing efficiency.Practical applications: The pharmaceutical, cosmetic, and infant formula industry can adopt this technology to more efficiently extract the highly nutritional and functional yolk lecithin or phospholipids from liquid yolk. Yolk drying is not necessary and ethanol is a desirable green solvent for yolk protein and lipid fractionation.Texturized egg yolk and total lipid extract at three stages of extraction using alcohol.