Comparison of analytical techniques for the determination of the positional distribution of fatty acids in triacylglycerols. Relationship with pig fat melting point and hardness

Abstract

This study was conducted to compare two of the most widely used methods for the determination of the positional distribution of fatty acids within the triacylglycerol molecules from fats of animal origin. Method A involves incubation of the triacylglycerol fraction with an aqueous suspension of the lipase enzyme, separation of the reaction products by thin-layer chromatography (TLC), and analysis of fatty acid methyl esters by gas-liquid chromatography. Method B eliminates the need for TLC. This technique makes use of the fact that methanolic-NaOH methylates only fatty acids esterified to glycerol. Our results demonstrated that method A data were in line with previous literature. Additionally, method A showed good correlations between fatty acid positional distribution and fat melting point and hardness. However, method B showed an underestimation of palmitic acid and lacked correlation with selected physical properties.

Keywords

• basic methylation
• fatty acids
• positional distribution
• tlc
• triacylglycerides