Extraction methods of fat from food samples and preparation of fatty acid methyl esters for gas chromatography: A review

Global trends moved towards fast food consumption due to the busy lifestyle of humans. Hence, the intake of fat-related food has exceeded the daily dietary reference intake (DRI) of fat, which caused multiple diseases. Analysis of the fatty acid profile plays a vital role in nutritional labelling and helps to understand the availability of diverse fatty acids among food commodities. This article reviews, general fatty acid extraction and derivatization techniques that have been developed in the past few decades due to the structural differences of fatty acids and briefed the steps involved in the complete process of fatty acid analysis using gas chromatography-mass spectrometry (GC–MS). Hence, the review mainly focused on conventional extraction methods, followed by microwave-assisted extraction (MAE), ultrasonic-assisted extraction (UAE), and supercritical fluid extraction (SFE) methods and widely used acid, base, and modified derivatization techniques. Importantly, this article compares the results of the previous studies in each section which assist to decide on the most appropriate pathway for the fatty acid analysis for different selected food types. Therefore, it is hoped that this review may help researchers to develop existing experimental methods and to improve ‘bad’ fatty acid level mitigation techniques in future.