Phytosteryl Esters Encapsulated in Liposomes as Bioactive Additives in Mayonnaise

Area of Science:

• Food Science
• Nutritional Biochemistry
• Lipid Chemistry

Background:

• Phytosterols offer cardiovascular benefits by reducing LDL cholesterol.
• Phytosterols are prone to degradation during food processing and storage.
• Liposomal encapsulation can improve phytosterol stability and bioavailability.

Purpose of the Study:

• To assess the stability of phytosterols within liposomes in mayonnaise under simulated storage and frying conditions.
• To evaluate the impact of liposomal encapsulation on phytosterol degradation during thermal processing.

Main Methods:

• Mayonnaise formulations with varying concentrations (2-8%) of liposomes encapsulating stigmasterol oleate were prepared.
• Samples were subjected to controlled heating: 60 °C for 8 hours and 180 °C for 30-120 minutes.
• Fat content, fatty acid profiles, oleic acid, and stigmasterol levels were quantified.

Main Results:

• Liposomal mayonnaise maintained high fat content (97-98%) at 60 °C, but it decreased to 75% after 120 min at 180 °C.
• Oleic acid levels remained stable in liposome-enriched mayonnaise.
• Stigmasterol loss was significantly reduced (3-25%) with liposomes at 60 °C compared to controls (79% loss).
• At 180 °C for 90-120 min, liposomal encapsulation offered limited protection, with stigmasterol loss ranging from 90% to 100%.

Conclusions:

• Liposomal encapsulation of phytosterol esters improves their thermal-oxidative stability in mayonnaise during short-term heating.
• Liposomes do not fully protect phytosterols from degradation during prolonged, high-temperature processing.
• Further strategies may be needed to preserve phytosterols under severe thermal stress.