Raw veal, beef, pork, and chicken muscle tissues were extracted by a modified dry column. procedure in which silicic acid was incorporated in the trap of the column. This method separated cholesterol derivatives from the bulk of neutral lipids, phospholipids and cholesterol. Isolation of sterols by preparative thin layer chromatography followed by quantification by direct on-column capillary gas chromatography permitted measurement of 7-ketocholesterol, cholesterol 501, 6u-epoxide, and cholesterol 5P,6P-epoxide at concentrations less than 1 ppm. All muscle tissues contained the three cholesterol products in measurable quantities. 7-Ketocholesterol constituted more than 50% of the oxidation products in all samples.

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.

Polar lipids were extracted from raw, nitrite‐treated beef and pork by a dry column procedure. The polar‐lipid fraction had substantial activity in inhibiting the oxidation of linoleic acid as determined by a β‐carotene bleaching method and by conjugated diene formation. The antioxidant activity of the polar‐lipid fraction was stable over several months when stored in hexane at−20 C. Residual sodium nitrite, carbon‐nitroso and nitrogen‐nitroso compounds or products of the addition of nitrogen oxides to olefins do not seem to account for the antioxidant activity observed.

Safrole, isosafrole, and mixtures of the two compounds were added to boiled or cooked ham at the 100 ppm level to simulate products that might be obtained in a smoking process in which sassafras wood is used. Samples of the ham were extracted with mixtures of hexane:ethyl acetate by a modified "dry column" procedure and were freed from the bulk of the accompanying neutral lipids by HPLC or bv oreoarative TLC. Ouantitation was bv caoillarv GC with FID det&hon: Recoveries ranged from 85-956 depending on the procedure used.

The transesterification of cholesteryl stearate, oleate, linoleate, linolenate and arachidonate to the fatty acid methyl ester and free cholesterol under mild conditions is described. In adaptation of a published procedure the transesterification was carried out for two hr at room temperature in 1N NaOH in methanol:benzene (60:40, v/v). After addition of saturated sodium chloride solution the reaction mixture was extracted with ethyl acetate. The product mixture was checked for cholesterol oxides by HPLC fractionation followed by measurement of the oxides by direct on‐column capillary GC. Although transesterification of cholesteryl stearate and oleate was complete (>99%) in 30 min, a uniform reaction period of two hr, required by the polyunsaturated esters, was used for all cholesteryl esters. 7‐Ketocholesterol, a principal oxidation product, was unaffected by the reaction conditions.