Evaluation of trans fatty acids, carbonyl compounds and bioactive minor components in commercial linseed oils

Trans fatty acids (TFAs), associated with the risks of coronary heart disease and diabetes, are formed by isomerization of unsaturated fatty acids during refining of linseed oils. In this study, TFAs and the chemical characteristics (acid value, peroxide value, carbonyl compounds, bioactive minor components and fatty acids) in 32 commercial linseed oils were investigated, and the correlation among them were further analyzed. Results showed that C18:3 TFAs were predominant TFAs in linseed oils and about 9% of the samples had TFA contents above 2 g/100 g fat, as well as the average level of TFA in the refined samples was higher than that in the unrefined oils. The correlation analyses suggested C18:3 TFAs exhibited significant negative correlations with acid value, levels of acetone, trans-2-nonenal, campesterol and alpha-linolenic acid. These results provided a comprehensive insight of TFAs in linseed oil and had important implications for consumers and linseed oil industry.

Automated summary

The study found that C18:3 TFAs were the predominant TFAs in linseed oils, with about 9% of the samples having TFA contents above 2 g/100 g fat. The average level of TFAs in refined linseed oils was higher than that in unrefined oils. Correlation analyses showed that C18:3 TFAs exhibited significant negative correlations with acid value, levels of acetone, trans-2-nonenal, campesterol, and alpha-linolenic acid.