Work

Triacylglycerols are preferentially oxidized over free fatty acids in heated soybean oil

Year: 2021

Type: article

Abstract: In oil, free fatty acids (FFAs) are thought compared the efficiency of hydrolysis wto be the preferred substrate for lipid oxidation although triacylglycerols (TAGs) are the predominant lipid class. We determined the preferential oxidation substrate (TAGs versus FFAs) in soybean oil heated at 100 °C for 24 h, after validating a method for quantifying esterified and free lipid oxidation products (i.e., oxylipins) with mass-spectrometry. Reaction velocities and turnover (velocity per unit substrate) of FFA, and free and TAG-bound (esterified) oxylipins were determined. FFA hydrolysis rate and turnover were orders of magnitude greater (16-4217 fold) than that of esterified and free oxylipin formation. The velocity and turnover of TAG-bound oxylipins was significantly greater than free oxylipins by 282- and 3-fold, respectively. The results suggest that during heating, TAGs are preferentially oxidized over FFAs, despite the rapid hydrolysis and availability of individual FFAs as substrates for oxidation. TAG-bound oxylipins may serve as better markers of lipid oxidation.

Source: npj Science of Food

DOI: 10.1038/s41538-021-00086-3

Authors: Qing Shen, Zhichao Zhang, Shiva Emami, Jianchu Chen, Juliana Maria Leite Nobrega de Moura Bell, Ameer Y. Taha

Institutions: Zhejiang University, University of California, Davis

Language: English

Topic: Edible Oils Quality and Analysis

Subfield: Organic Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,190

Funders: U.S. Department of Agriculture, Zhejiang University, National Institute of Food and Agriculture, Center for Advanced Processing and Packaging Studies, Ohio State University