Liquid-Liquid Microextraction Method Coupled with GC-FID Analysis to Evaluate the Possible Adulteration of Corn Oil with Different Vegetable Oils

Corn oil, a widely used and affordable food ingredient, undergoes fatty acid analysis primarily through Gas Chromatography (GC) equipped with a Flame Ionization Detector (FID) after the liquid-liquid microextraction method. This efficient technique identifies and quantifies Fatty Acid Methyl Esters (FAMEs) in pure and contaminated corn oils. The process involves liquid-liquid microextraction and transesterification with methanol for fatty acid methylation. FAMEs separation utilizes a specialized cyano-column, enabling the detection of positional and geometrical isomers with carbon chain lengths ranging from C۸ to C۲۸. The GC-FID method successfully resolves partial FAMEs overlap and quantifies conjugated fatty acids like Conjugated Linoleic Acid (CLA). Analysis revealed linoleic acid as the predominant monounsaturated fatty acid, followed by saturated oleic acid and unsaturated palmitic acid. Palm oil (PaO) exhibited a high palmitic acid content, exceeding ۳۸%, while soybean oil (SoO) was characterized by α-linoleic acid (polyunsaturated) levels above ۴.۵%. The effect of important factors on the extraction efficiency including the type of extraction solvent, the volume of extraction solvent, extraction temperature, and extraction time were investigated, and the optimal values were determined. Under optimal conditions, the extraction process was used for the analysis FAMEs, and valuable results were obtained.

کلیدواژه ها:

Edible oils ، Vegetable oils ، Corn oil ، Fatty acid ، Liquid-liquid microextraction ، GC-FID