A rapid and accurate extraction procedure for analysing free amino acids in meat samples by GC-MS

Abstract

This study evaluated the use of a mixer mill as the homogenization tool for the extraction of free amino acids in meat samples, with the main goal of analyzing a large number of samples in the shortest time and minimizing sample amount and solvent volume. Ground samples (0.2 g) were mixed with 1.5 mL HCl 0.1 M and homogenized in the mixer mill. The final biphasic system was separated by centrifugation. The supernatant was deproteinized, derivatized and analyzed by gas chromatography. This procedure showed a high extracting ability, especially in samples with high free amino acid content (recovery = 88.73-104.94%). It also showed a low limit of detection and quantification (3.8 · 10-4-6.6 · 10-4 g L-1 and 1.3 · 10-3-2.2 · 10-2 g L-1, resp.) for most amino acids, an adequate precision (2.15-20.15% for run-to-run), and a linear response for all amino acids (R 2 = 0.741-0.998) in the range of 1-100 μg mL-1. Moreover, it takes less time and requires lower amount of sample and solvent than conventional techniques. Thus, this is a cost and time efficient tool for homogenizing in the extraction procedure of free amino acids from meat samples, being an adequate option for routine analysis.