The structure of triglycerides, i.e. the positioning of the fatty acids on the glycerol backbone, is of key importance during digestion and absorption of fatty acids
Delplanque, B., Gibson, R., Koletzko, B., Lapillonne, A., & Strandvik, B. (2015). Lipid Quality in Infant Nutrition: Current Knowledge and Future Opportunities. In Journal of Pediatric Gastroenterology and Nutrition. https://doi.org/10.1097/MPG.0000000000000818
. LCSFAs such as palmitic acid are best absorbed when positioned in the sn-2 position of the glycerol backbone in triglycerides
Innis, S. M. (2011). Dietary triacylglycerol structure and its role in infant nutrition. In Advances in Nutrition. https://doi.org/10.3945/an.111.000448
. Fatty acids positioned at sn-1 and sn-3 position are released as free fatty acids during fat digestion. Free LCSFAs can potentially form insoluble fatty acid soap complexes with minerals such as calcium. Besides the limited bioavailability of calcium and fatty acids
López-López, A., Castellote-Bargalló, A. I., Campoy-Folgoso, C., Rivero-Urgel, M., Tormo-Carnicé, R., Infante-Pina, D., & López-Sabater, M. C. (2001). The influence of dietary palmitic acid triacylglyceride position on the fatty acid, calcium and magnesium contents of at term newborn faeces. Early Human Development. https://doi.org/10.1016/S0378-3782(01)00210-9
, fatty acid soap complexes are associated with constipation and gut discomfort in infants
Quinlan, P. T., Lockton, S., Irwin, J., & Lucas, A. L. (1995). Literature Reviews: Pediatric Gastroenterology: The Relationship Between Stool Hardness and Stool Composition in Breast- and Formula-Fed Infants Quinlan PT, Lockton S, Irwin J, et al. J Pediatr Gastroenterol Nutr. 1995;20:81-90. Clinical Pediatrics. https://doi.org/10.1177/000992289503400609
. Specific fat sources such as natural cow’s milk fat contain a higher percentage of sn-2 positioned LCSFAs in comparison to standard vegetable fat blends
Hageman, J. H. J., Danielsen, M., Nieuwenhuizen, A. G., Feitsma, A. L., & Dalsgaard, T. K. (2019). Comparison of bovine milk fat and vegetable fat for infant formula: Implications for infant health. International Dairy Journal, 92, 37–49. https://doi.org/10.1016/j.idairyj.2019.01.005
. Infant milk formulas with a higher sn-2 palmitate content have been shown to lead to lower fatty acid soap complexes in stool samples
Nowacki, J., Lee, H. C., Lien, R., Cheng, S. W., Li, S. T., Yao, M., Northington, R., Jan, I., & Mutungi, G. (2014). Stool fatty acid soaps, stool consistency and gastrointestinal tolerance in term infants fed infant formulas containing high sn-2 palmitate with or without oligofructose: A double-blind, randomized clinical trial. Nutrition Journal, 13(1), 1–11. https://doi.org/10.1186/1475-2891-13-105
, suggesting enhanced digestive comfort
Quinlan, P. T., Lockton, S., Irwin, J., & Lucas, A. L. (1995). Literature Reviews: Pediatric Gastroenterology: The Relationship Between Stool Hardness and Stool Composition in Breast- and Formula-Fed Infants Quinlan PT, Lockton S, Irwin J, et al. J Pediatr Gastroenterol Nutr. 1995;20:81-90. Clinical Pediatrics. https://doi.org/10.1177/000992289503400609
.