Triacylglycerol structure and interesterification of palmitic and stearic acid-rich fats: an overview and implications for cardiovascular disease

Abstract

The position of fatty acids in the TAG molecule (sn-1, sn-2 and sn-3) determines the physical properties of the fat, which affects its absorption, metabolism and distribution into tissues, which may have implications for the risk of CHD. The TAG structure of fats can be manipulated by the process of interesterification, which is of increasing commercial importance, as it can be used to change the physical characteristics of a fat without the generation of trans-fatty acids. Interesterified fats rich in long-chain SFA are commercially important, but few studies have investigated their health effects. Evidence from animal and human infant studies suggests that TAG structure and interesterification affect digestibility, atherogenicity and fasting lipid levels, with fats containing palmitic and stearic acid in the sn-2 position being better digested and considered to be more atherogenic. However, chronic studies in human adults suggest that TAG structure has no effect on digestibility or fasting lipids. The postprandial effects of fats with differing TAG structure are better characterised but the evidence is inconclusive; it is probable that differences in the physical characteristics of fats resulting from interesterification and changes in TAG structure are key determinants of the level of postprandial lipaemia, rather than the position of fatty acids in the TAG. The present review gives an overview of TAG structure and interesterified palmitic and stearic acid-rich fats, their physical properties and their acute and chronic effects in human adults in relation to CHD.

Effect of sex, dietary glycerol or dietary fat during late fattening, on fatty acid composition and positional distribution of fatty acids within the triglyceride in pigs

“…The possibility of altering the FA composition at the Sn-2 location of the TAG by dietary intervention during the fattening phase is very limited. This observation has important practical application, because saturated FA in the Sn-2 position might have more detrimental effect on human health than those located in the external Sn-1,3 location (Berry, 2009), thus reducing pork consumer acceptability. More research efforts are needed to elucidate the potential effect of management conditions, including genetics and more prolonged feeding regimens, on Sn-2 fatty acid composition in pig fat.…”

Effect of sex and dietary treatment on the composition and rheological properties of dry-cured ham subcutaneous fat

“…This finding supports the theory that there is a limited possibility of altering FA composition at the sn-2 location of the TAG by dietary intervention during the fattening phase (Segura et al 2015a). This is a matter of interest, because it is believed that SFA in the sn-2 position have a more detrimental health effect than those located in the external sn-1,3 location (Berry 2009), thus negatively affecting pork consumer acceptability. Nevertheless, further studies are needed.…”

<i>sn</i>-2 Hypothesis: a Review of the Effects of Palm Oil on Blood Lipid Levels

“…Conversely, fatty acids that are situated at the sn-2 position of TG are prone to be transported to the liver instead of adipose tissue, attributed to the stereospecific activity of lipoprotein lipase for the sn-1 and sn-3 positions of TG 21,22 .…”