Enzymatic Synthesis and Characterization of MLM-type Structured Lipid Using Grapeseed Oil and Capric Acid

Area of Science:

• Lipid chemistry and enzymology
• Food science and technology
• Biocatalysis

Background:

• Structured lipids (SL) offer potential health benefits by modifying fatty acid profiles.
• Grapeseed oil (GS oil) is a common edible oil source suitable for modification.
• Optimizing the incorporation of specific fatty acids like C10:0 is crucial for SL functionality.

Purpose of the Study:

• To optimize reaction conditions for C10:0 incorporation into grapeseed oil.
• To characterize the resulting structured lipid product, focusing on TAG species and fatty acid positions.
• To evaluate the impact of SL synthesis and purification on antioxidant activity.

Main Methods:

• Taguchi method was employed to optimize reaction parameters (substrate ratio, enzyme load, temperature, time).
• Acidolysis reactions were performed using immobilized lipases: Lipozyme® RM IM and Lipozyme® 435.
• High-Performance Liquid Chromatography (HPLC) and Gas Chromatography (GC) were used for analysis; scaled-up reactions and short path distillation (SPD) were utilized for purification and characterization.

Main Results:

• Optimal conditions (1:3 GS oil:C10:0 ratio, 5% enzyme load, 65°C, 12h) were identified for both enzymes.
• Lipozyme® RM IM demonstrated significantly higher total C10:0 incorporation (60.08 mol%) compared to Lipozyme® 435 (50.78 mol%).
• Purified SL (72.96 wt% yield) showed reduced antioxidant activity post-SPD due to tocopherol loss, but retained MLM-type TAG structure with high C10:0 content.

Conclusions:

• Lipozyme® RM IM is a superior biocatalyst for producing MLM-type structured lipids with high C10:0 content from grapeseed oil.
• The optimized 12-hour process yields a functional SL with potential nutritional and health advantages.
• Short path distillation effectively purifies SL but necessitates consideration of antioxidant component retention.