Abstract
The M. longissimus thoracis of horse which had liberal quantities of fat interspersed within lean (marbling meat) from 5 animals and had less fat within lean (lean meat) from 5 animals were used to compare the chemical composition and lipid and fatty acid composition.
The contents of moisture, crude protein and crude fat were 64.5%, 18.6% and 16.3% in marbling meat and 72.7%, 22.2% and 2.1% in lean meat.
The detectable components in intramuscular lipid in this experiment were triacylglycerol (TG), free fatty acid (FFA), cholesterol (CS), phosphatidyl choline (PC), phosphatidyl ethanolamine (PE), sphingomyeline (SPM) and lysophosphatidyl choline (LPC). The contents of neutral lipid fraction (NL) and phospholipid fraction (PL) were 88.8% (TG : 71.6%, FFA : 9.6% and CS : 7.6%) and 11.3% (PE : 1.8%, PC : 6.2%, SPM : 2.0% and LPC : 1.3%) in marbling meat, respectively, and 66.1% (TG : 57.7%, FFA : 2.7% and CS : 5.7%) and 33.9% (PE : 4.9%, PC : 18.4%, SPM : 6.2% and LPC : 4.4%) in lean meat, respectively. The contents of NL, TG and FFA were significantly higher in marbling meat than lean meat which was significantly richer in PL, PC and SPM.
The predominant fatty acids of TL were C14 : 0, C16 : 0, C16 : 1, C18 : 0, cis C18 : 1, C18 : 2 and C18 : 3. Although the marbling meat was significantly richer in cis C18 : 1, C18 : 3, n-3 group fatty acids and sum of unsaturated fatty acid than lean meat, the contents of C15 : 1, iso C18 : 0, C20 : 4, C22 : 5, and sum of saturated fatty acid were significantly higher in lean meat than in marbling meat. The concentration of C18 : 3 in animal lipids is usually low, but it was found in considerable quantity (9.9% for marbling meat and 4.5% for lean meat) in the intramusular lipid of the horses investigated.
The predominant fatty acids of NL were C14 : 0, C16 : 0, C16 : 1, C18 : 0, cis C18 : 1, C18 : 2 and C18 : 3. The amount of C18 : 3 in both meats was higher in NL than in PL. The NL of marbling meat was significantly higher in C14 : 0, C18 : 0, C18 : 2, n-3 and n-6 group fatty acids, but in lean meat, C16 : 0 and C16 : 1 were significantly higher.
The fatty acid composition in PL was considarably richer in C18 : 0, C18 : 2, C20 : 4, sum of unsaturated fatty acid and n-6 group fatty acids than in TL and NL. Compared with the fatty acid composition of lean meat, the marbling meat was significantly higher in cis C18 : 1 and less in C20 : 3, C20 : 4, C22 : 5, C22 : 6 and n-3 group fatty acids.
From the nutritional point of view, the large amounts of C18 : 2 and C18 : 3 in TL and NL and of C18 : 2, C18 : 3 and C20 : 4 in PL from horse intramuscular lipid should be paid much attention.
