Fatty Acid Composition of Meat Tissue Lipids

Abstract

The lipids extracted from beef and pork muscle were fractionated into triglycerides, cephalins, and a mixture of lecithins and sphingomyelins. The fatty acid composition of these fractions was determined, and the possible effect of phospolipids on meat flavor was evaluated.Cold-water extracts of lean beef and lean pork contain desirable meat-flavor precursors. These extracts do not, however, contain any appreciable proportion of the lipids present in the lean meat. Lipids, particularly the phospholipids, are among the more unstable constituents of lean meat; and Younathan and Watts (1960) have recently suggested that the phospholipids play a major role in accelerating flavor deterioration in cooked meats. This paper is concerned with the effect on flavor of the lipids present in lean meat prior to preparation for consumption. Our studies have therefore been made on aged lean beef and lean pork. The meat tissue lipids have been separated into neutral lipids and phospholipids, the fatty acids present in these fractions determined, and the possible contribution of these fractions to either desirable or undesirable flavor evaluated. EXPERIMENTAL Extraction of lipids from muscle. As in previous flavor studies (Hornstein and Crowe, 1960; Hornstein et al., 196Ob), fresh meat 'was aged 10 days at 36-38°F. Several of the muscles were then dissected and stored at 0°F.As needed, samples of meat were thawed, fat was removed, and the trimmed muscle was cut into small sections. The extraction procedure was essentially that of Folch et al. (1957). One hundred grams of the diced meat were blended for 5 min with 900 ml of cold 2:l chloroform-methanol (all solvents are reagent grade and all solvent ratios are v/v) in an Oster blender (mention of trade names is for identification and implies no endorsement). The slurry was immediately filtered, then mixed with 0.2 its volume of water in a Z-L separatory funnel, and allowed to stand overnight at >S"C. The separation into two phases was clean-cut. The lower phase was drained and, without further washing, dried over anhydrous sodium sulfate, concentrated to a small volume on a rotary evaporator at room temperature under partial vacuum, quantitatively transferred with several ml of chloroform to a tared 125-ml Erlenmeyer flask, and dried on the rotary evaporator.Residual solvent was removed under high vacuum. The weighed residue was redissolved in 20 ml of 2O:l chloroform-methanol.Small amounts of undissolved material were removed by centrifugation. Separationof neutral fat from phospholipids by column chromatography.Fifty grams of silicic acid (Mallinckrodt AR loo-mesh) heated overnight at 130°C were slurried with chloroform and poured into a 2.5 X 90-cm column fitted with a sintered-glass disc. Air bubbles were removed by stirring the mixture with a long glass rod. The silicic acid was allowed to settle and the chloroform drained under slight nitrogen pressure. When the column was compact and with at least 15 cm of liquid above the interface, anhydrous sodium sulfate was added to f...

Fatty Acid Composition of Goat Organ and Muscle Meat of Alpine and Nubian Breeds

“…The respective levels of oleic acid for the liver, heart, kidney, LD and BF muscles indicated that the skeletal muscles contained more than 1.5 times, in some instances nearly double, that in liver, heart and kidney. This agreed with previous studies with other species (Hornstein et al, 1961;Duncan and Garton, 1967;Eichhom et al, 1986;Sinclair and O'Dea, 1987). Analyses of triglycerides derived from various tissues of pig, horse, steer and sheep have shown that those of internal body tissues contained much higher proportion of saturated fatty acids than those of external or sub-cutaneous tissues (Hilditch and Williams, 1964;Eichhorn et al, 1986;Devendra, 1988).…”

Total Lipids and Phospholipids in Turkey Tissues

“…The variation, although small, shows that phosphatidylethanola mine tends to be present in greater quantities in the tis sues with less total lipid content while the sphingomyelin is relatively somewhat more abundant in the tissues with greater total lipid content. The lecithin content agrees quite well with the values reported by Hornstein et al (1961) for aged pork muscle, but the cephalin content found in this study is substantially lower than reported.…”

Nutrient Content of Variety Meats. III. Fatty Acid Composition of Lipids of Certain Raw and Cooked Variety Meatsa

“…The fatty acid distribution in beef tongue lipid approximated that foulid in beef and pork muscle tissue (Hornstein et al, 1961 ;Slover et al, 1964). The total polyunsaturated fatty acid content was relatively low, the fatty acids consisting of 5-6s linoleic plus arachidonic acids.…”