Research on Relationship between Beef Marbling Standard and Fatty Acid Composition of Longissimus Dorsi

【Objective】The objective of this experiment was to determine fatty acids changes with different intramuscular or subcutaneous fat content of Chinese Yellow cattle.【Method】Thirty beef longissimus dorsi and the back fat from bulls of Chinese Yellow Cattle with marbling grade of 12, 3, and 4 were used, fat content and fatty acid profiles were detected. 【Result】 The results obtained show a great variability in the content of water and intramuscular fat and the percentages of fatty acids. Water content and intramuscular fat content (IMF) correlated with beef marbling. In intramuscular fat and subcutaneous fat as well, 18:1cis-9, which is one of the monounsaturated fatty acids (MUFA), was the main fatty acid, followed by two saturated fatty acids (SFA), 16:0 and 18:0. The percentage of polyunsaturated fatty acids (PUFA) was relatively lower. 【Conclusion】 The percentages of 16:0, 18:0 and SFA were not correlated with IMF, which showed that the percentage of 16:0, 18:0 and SFA in beef longissimus dorsi were absolutely the same with subcutaneous fat. The percentages of 18:1cis-9, MUFA and ratio of M/S were positively correlated with IMF, with beef marbling increased from Grade 4 to Grade 2, the percentages of 18:1cis-9 and MUFA and the ratio of M/S increased. However, the percentages of 18:2cis-9,12, PUFA and n-6PUFA and the ratio of P/S, n-6/n-3 were negatively correlated with IMF, and with beef marbling increased, the percentages of 18:2cis-9,11, PUFA, n-6PUFA and the ratio of P/S, n-6/n-3 decreased significantly. The composition of n-3PUFA in subcutaneous fat was significantly lower than that of beef intramuscular fat.