Sample Preparation Methods for Fatty Acid Analysis in Different Raw Meat Products by GC-FID

In recent decades there has been a growing increase in meat consumption by the population worldwide, increasing from 30 kg/person/year in the 1980s to 43.4 kg in 2015. Fatty acid (FA) composition in raw meat products strongly influences their chemical and sensory characteristics and nutritional quality. Thus, analyzing the FA profile in meat products is considerably important. Analysis of the FA profile in meat products requires obtaining volatile FA methyl esters (FAMEs), which are analyzed by gas chromatography equipped with a flame ionization detector (GC-FID). Methodologies to prepare FAMEs are extremely varied and are constantly improving. Therefore, this review describes the main methodologies used for the sample preparation for FA analysis by GC-FID in raw meat products. Most of the articles evaluated presented the production of FAMEs in two steps (lipid extraction and derivatization). The most systematic methodologies in the first step were Folch and Bligh and Dyer methods, and KOH/methanol and acetyl-chloride/methanol were the most recurrent agents in the second step. Sample preparation showed yet substantial differences in the initial processing of the sample, thermal treatment conditions, use or not of sonication and microwave system, solvent evaporation methods, and the total time of sample preparation. We believe that this review will be relevant for researchers to find relevant information for choosing the most appropriate methodology for use in their laboratories, noting the reagents, equipment, and time required, as well as the sample studied, always looking for the development of faster methods, with low cost and environmental impact.