Chen Z Y, Pelletier G, Hollywood R, Ratnayake W M
Nutrition Research Division, Health Protection Branch, Health Canada, Ottawa, Ontario.
Lipids. 1995 Jan;30(1):15-21. doi: 10.1007/BF02537037.
The fatty acid composition, total trans content (i.e., sum of all the fatty acids which may have one or more trans double bonds) and geometric and positional isomer distribution of unsaturated fatty acids of 198 human milk samples collected in 1992 from nine provinces of Canada were determined using a combination of capillary gas-liquid chromatography and silver nitrate thin-layer chromatography. The mean total trans fatty acid content was 7.19 +/- 3.03% of the total milk fatty acids and ranged from 0.10 to 17.15%. Twenty-five of the 198 samples contained more than 10% total trans fatty acids, and thirteen samples contained less than 4%. Total trans isomers of linoleic acid were 0.89% of the total milk fatty acids with 18:2 delta 9c,13t being the most prevalent isomer, followed by 18:2 delta 9c,12t and 18:2 delta 9t,12c. Using the total trans values in human milk determined in the present study, the intake of total trans fatty acids from various dietary sources by Canadian lactating women was estimated to be 10.6 +/- 3.7 g/person/d, and in some individuals, the intake could be as high as 20.3 g/d. The 18:1 trans isomer distribution differed from that of cow's milk fat but was remarkably similar to that in partially hydrogenated soybean and canola oils, suggesting that partially hydrogenated vegetable oils are the major source of these trans fatty acids.
采用毛细管气液色谱法和硝酸银薄层色谱法相结合的方法，测定了1992年从加拿大9个省份采集的198份人乳样本中脂肪酸的组成、总反式含量（即所有可能含有一个或多个反式双键的脂肪酸的总和）以及不饱和脂肪酸的几何异构体和位置异构体分布。总反式脂肪酸含量平均占乳脂肪酸总量的7.19±3.03%，范围为0.10%至17.15%。198份样本中有25份总反式脂肪酸含量超过10%，13份样本含量低于4%。亚油酸的总反式异构体占乳脂肪酸总量的0.89%，其中18:2Δ9c,13t是最普遍的异构体，其次是18:2Δ9c,12t和18:2Δ9t,12c。根据本研究测定的人乳中总反式值，估计加拿大哺乳期妇女从各种饮食来源摄入的总反式脂肪酸为10.6±3.7克/人/天，在某些个体中，摄入量可能高达20.3克/天。18:1反式异构体的分布与牛乳脂肪不同，但与部分氢化大豆油和菜籽油中的分布非常相似，这表明部分氢化植物油是这些反式脂肪酸的主要来源。
