Determination of total fat in meat and meat products by a rapid, dry column method

A rapid, dry column method is proposed for determining fat in meat and meat products. Unlike AOAC procedures 24.005 and 24.006, this procedure measures total rather than crude fat. A 5 g sample is blended with anhydrous sodium sulfate in a mortar and is then reduced to a fine powder with Celite 545. The fat is eluted on a glass column, using dichloromethane-methanol (9+1). Solvent is removed from the eluate, and the resulting residue is weighed to calculate total fat of the sample. A determination takes 2.5 hr or less. Fat levels ranged from 7 to 90% in 15 meat samples. Quadruplicate determinations by this method and duplicate determinations by 24.005(a) yielded overall means of 29.9 and 29.3% fat, respectively. Repeatability was 0.3% fat. The 0.6% mean difference is significant (P = 0.05) and represents a more complete extraction of polar lipids by the proposed method. Results of determinations by this method are compared with results by an accepted but laborious chloroform/methanol procedure for total fat recovery. Overall means and standard deviations of replicate determinations on 4 meats containing 4-30% fat were 12.8 +/- 0.1 with this method and 12.7 +/- 0.1 with the reference method.