A laboratory efficient method for intramuscular fat analysis

A new procedure to extract intramuscular fat (IMF) was developed to minimize sample amount, solvent use and time of analysis. Lyophilised samples (200 mg) were accurately weighed in a safe-lock micro test tube, homogenized in 1.5 mL dichloromethane-methanol (8:2) and mixed in a mixer mill (MM400, Retsch technology). The final biphasic system was separated by centrifugation (8 min, 10,000 rpm). The extraction was repeated three times. Solvent was evaporated under nitrogen stream and lipid content was gravimetrically determined. Results from 64 determinations were compared to those obtained with other referred method and showed a linear response over the whole range of IMF content (1.6–6.9 g/100 g sample). Moreover, the analysis with different methodology of six replica from the same sample showed lowest variability (standard deviation intra-method) for the new methodology proposed over a wide range of IMF content. A cost and time efficient lipid extraction procedure was developed without loss of precision and accuracy and with a fatty acid profile comparable to other protocols.