Extraction of Lipids and Functional Properties of Defatted Egg Yolk Powder Obtained Using a One-Step Organic Solvent...

Area of Science:

• Food Science
• Protein Chemistry
• Lipid Extraction

Background:

• Spray-dried egg yolk is a valuable ingredient but contains significant lipids.
• Lipid content can affect the functional properties of egg yolk proteins.
• Efficient lipid extraction is crucial for creating value-added egg yolk ingredients.

Purpose of the Study:

• To evaluate the effectiveness of different organic solvents for lipid extraction from spray-dried egg yolk.
• To assess the impact of lipid extraction on the protein content and functional properties of the defatted egg yolk powder.
• To identify the optimal solvent for preserving protein functionality.

Main Methods:

• A one-step organic solvent lipid extraction method was employed.
• Tested solvents included chloroform:methanol (CM), methyl-tert-butyl ether (MTBE), and hexane:isopropanol (HI).
• Analyzed protein and lipid content, protein solubility, and gel properties (hardness, springiness, cohesiveness, gumminess) of the extracted powders.

Main Results:

• Defatted egg yolk powder showed increased protein (21-30%) and decreased lipid (22-25%) content (p < 0.05).
• Chloroform:methanol (CM) significantly reduced protein solubility (20% to 4%, p < 0.05), indicating denaturation.
• Gels from MTBE and HI extracts were harder than controls (p < 0.05), with MTBE gels exhibiting superior springiness, cohesiveness, and gumminess (p < 0.05).

Conclusions:

• Methyl-tert-butyl ether (MTBE) is the most effective solvent for lipid extraction from spray-dried egg yolk, preserving protein functionality.
• MTBE extraction yields a defatted egg yolk powder with enhanced protein content and desirable gel-forming properties.
• This optimized extraction process can lead to improved functional ingredients derived from egg yolk.