Bracco U
Nestlé Research Centre, Lausanne, Switzerland.
Am J Clin Nutr. 1994 Dec;60(6 Suppl):1002S-1009S. doi: 10.1093/ajcn/60.6.1002S.
Stereospecific distribution of fatty acids on triacylglycerol structures influences the technological behavior of fats as well as their absorption fate. Long-chain fatty acids in external (sn-1 and sn-3) positions may impair fat absorption and therefore the physiological response to dietary fats. Lower digestibility of bovine milk fat compared with that of human milk is related to the different position of palmitic acid in both fats. Stereospecific analysis of cocoa butter and fats containing stearic acid of the stearic-oleic-stearic acid (SOS) type showed that long-chain saturated fatty acids are almost exclusively present in sn-1 and sn-3 positions, which could explain their impaired absorption and therefore their neutral effect on serum lipid in humans despite their saturation and chain length. The true energy value of these fats therefore needs to be verified in mixed diets.
脂肪酸在三酰甘油结构上的立体特异性分布会影响脂肪的工艺性能及其吸收情况。处于外部（sn-1和sn-3）位置的长链脂肪酸可能会损害脂肪吸收，进而影响对膳食脂肪的生理反应。与母乳相比，牛乳脂肪的消化率较低，这与两种脂肪中棕榈酸的不同位置有关。对可可脂和含有硬脂酸-油酸-硬脂酸（SOS）型硬脂酸的脂肪进行立体特异性分析表明，长链饱和脂肪酸几乎只存在于sn-1和sn-3位置，这可以解释它们吸收受损的原因，因此尽管它们具有饱和性和链长，但对人体血清脂质仍具有中性作用。因此，这些脂肪在混合饮食中的真实能量值需要进行验证。
