Quantitative analysis of sorbic acid in cereal products using GC-MS-SIM

Abstract

Sorbic acid is a natural organic acid added to food and beverages as a preservative agent. Although sorbic acid is widely used as a mould inhibitor in a variety of foods, an off-odour might develop due to the catabolism of sorbic acid by sorbate resistant strains of yeasts and moulds. The concentration of sorbic acid in eight packaged cereal samples (commercial lavash bread, flour tortillas, biscuit dough, bread crumbs, English muffin, Scottish white plain bread, wheat bread, whole meal bread) were investigated by gas chromatography with mass spectrometry detection in the selected ion monitoring mode (GC-MS-SIM). Five specific molecular ions (39, 41, 67, 97, 112) were monitored. The ion 97 was selected as a target ion (m/z) for quantification. Vacuum dried tarhana, with no sorbate preservative, was used as a control. Seven units of the same product were purchased and used. Gas chromatography olfactometry (GC-O) was utilized to determine detection and odour activity values for sorbic acid. Lavash bread showed the highest sorbate concentration (5.12±1.43 mg/L) and odour activity value (64.0) among analysed samples.