Depolymerization and Oxidation Events in Used Frying Oils Under Conditions Simulating Gastric Digestion.

Area of Science:

• Food Chemistry
• Nutritional Science
• Analytical Chemistry

Background:

• Chemical modifications in frying oils post-ingestion remain largely unknown.
• Understanding these changes is crucial for assessing dietary oil safety.

Purpose of the Study:

• To investigate depolymerization and oxidation of frying oil compounds under simulated gastric conditions.
• To quantify the chemical transformations occurring in used sunflower oil during in vitro digestion.

Main Methods:

• In vitro digestion of used sunflower oil at pH 1.2.
• Analysis of triacylglycerols (TAG), oxidized TAG monomers (oxTAGM), TAG dimers (TAGD), and higher oligomers (TAGO) using chromatography.
• Quantification of epoxy, hydroxy, and keto fatty acyls via gas-liquid chromatography after transesterification.

Main Results:

• Significant depolymerization (up to 70%) of oil compounds was observed under simulated gastric conditions.
• Increased levels of unoxidized TAG and hydroxy fatty acid methyl esters were detected post-digestion.
• Demonstrated substantial structural modifications in frying oil components during gastric digestion.

Conclusions:

• Gastric digestion induces significant chemical alterations in compounds found in frying oils.
• The formation of novel compounds warrants further research into their health implications.
• This study provides quantitative data on the fate of frying oil components in the digestive system.