肃南牦牛不同部位脂肪中脂肪酸组成分析

Analysis of fatty acid composition in fat in different parts of Sunan yak

中文关键词:  牦牛脂肪  脂肪酸  品质评价  气相色谱-质谱法  主成分分析法

英文关键词:yak fat  fatty acids  quality evaluation  gas chromatography-mass spectrometry  principal component analysis

中文摘要:

      目的 评价肃南牦牛不同部位脂肪品质。方法 采集肃南牦牛5个不同部位脂肪(肋条表面脂肪、臀肌脂肪、肾周脂肪、肠周脂肪及皮下脂肪), 测定牦牛不同部位脂肪酸价(acid value, AV)、过氧化值(peroxide value, POV), 并采用气相色谱-质谱法(gas chromatography-mass spectrometry, GC-MS)对5个不同部位脂肪中脂肪酸含量进行测定, 采用面积归一化法进行定量, 探究肃南牦牛不同部位脂肪组成成分的差异性, 并结合多元统计分析讨论脂肪酸成分含量对不同部位脂肪品质的影响。结果 以脂肪酸种类及含量为评定指标, 在5个不同部位中均检出36种脂肪酸, 以硬脂酸为主; 其次是油酸、棕榈酸和亚油酸含量较高。对不同部位的饱和脂肪酸(saturated fatty acids, SFA)、单不饱和脂肪酸(monounsaturated fatty acids, MUFA)、多不饱和脂肪酸(polyunsaturated fatty acids, PUFA)含量分析表明, 皮下脂肪的不饱和脂肪酸/饱和脂肪酸(unsaturated fatty acid/saturated fatty acids, UFA/SFA)比值较大, 风味较佳。主成分分析(principal component analysis, PCA)表明前3个主成分的累积贡献率高达99.41%, 很好地实现了牦牛5个不同部位脂肪的区分。结论 牦牛脂肪中脂肪酸种类丰富, 富含多不饱和脂肪酸。不同部位脂肪酸含量有着显著性差异(P<0.05), 主成分分析对牦牛不同部位脂肪品质进行综合评价是客观、可行的, 为牦牛不同部位脂肪鉴别提供了有效的新方法。

英文摘要:

      Objective To evaluate the fat quality of different parts of Sunan yak. Methods Fat from 5 different parts (rib surface fat, gluteal muscle fat, perirenal fat, periintestinal fat and subcutaneous fat) of Sunan yak were collected, the fatty acid value (AV) and peroxide value (POV) of different parts of yak were measured, and the fatty acids content in the fat of 5 different parts were determined by gas chromatography-mass spectrometry (GC-MS), the area normalization method was used to explore the differences of fat components in different parts of Sunan yak, and combined with multivariate statistical analysis to discuss the effect of fatty acid content on fat quality in different parts. Results The type and content of fatty acids were used as evaluation indexes, 36 kinds of fatty acids were detected in 5 different parts, mainly stearic acid; this was followed by higher levels of oleic acid, palmic acid and linoleic acid. Analysis of saturated fatty acids (SFA), monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) content in different parts showed that the ratio of unsaturated fatty acid/saturated fatty acids (UFA/SFA) of the subcutaneous fat was larger, the flavor was better. Principal component analysis (PCA) showed that the cumulative contribution rate of the first 3 main components was as high as 99.41%, which made the distinction between fats in 5 different parts of yak. Conclusion There are many kinds of fatty acids in yak fat, which are rich in polyunsaturated fatty acids. There are significant differences in fatty acids content in different parts (P<0.05), and it is objective and feasible for PCA analysis to evaluate the fat quality of different parts of yak, which provides an effective new method for fat identification of different parts of yak.