Egg-Derived Lipids and Phospholipids as Emerging Functional Ingredients: Molecular Structure, Bioavailability, Metabolic Effects, and Food Applications

Summary

This narrative review synthesises evidence on the compartmentalised lipid structure of egg yolk, bridging molecular architecture, extraction methods, digestion pathways, and human metabolic outcomes. The authors argue that egg yolk should not be treated as compositionally uniform, and demonstrate how the distinct LDL plasma and HDL granule fractions differ in structure, digestibility, and metabolic effects. Whilst animal models show divergent effects between fractions, human evidence remains preliminary—a single crossover trial supports differential choline bioavailability from phospholipid-bound versus synthetic forms, but direct comparative digestion studies are lacking.

Regional applicability

The review addresses fundamental nutritional science applicable to any region consuming eggs, including the United Kingdom. However, most human evidence cited derives from controlled trials in healthy adults, and applicability to UK populations with varied dietary patterns or health conditions requires further investigation. The technological functionality findings may be directly relevant to UK food manufacturers developing egg-based functional ingredients.

Key measures

Molecular structure of egg-yolk lipids; bioaccessibility and gastrointestinal digestion kinetics; plasma choline and cholesterol response; emulsifying behaviour; technological functionality

Outcomes reported

A synthesis of egg-yolk lipid molecular architecture, extraction methods, gastrointestinal digestion, human bioavailability, metabolic fate, and technological functionality as stages of a single pathway. The review highlights compositional and metabolic differences between the triglyceride-dominant LDL plasma fraction and phospholipid-enriched HDL granule fraction of egg yolk.

Topic tags