Résumé
Infancy is characterized by significant growth and development that leads to very specific nutritional requirements. During this period, lipids and more particularly long-chain polyunsaturated fatty acids play an important role. To comply with the recommendations, European regulation have recently evolved and now requires fortification of infant follow-on formulas (IFF) with docosahexaenoic acid (DHA) which strongly impacts their oxidative stability. The aim of this study was to improve the lipid profile and oxidative stability of DHA-enriched IFF by using structural and formulation lipid levers. To do so, a model IFF representative of marketed products was formulated and declined by varying the saturated fatty acids sources (refined (POM) or unrefined (RPOM) palm oil, coconut oil (COM), and dairy fat (DFOM)), the emulsifiers (soy lecithin or dairy phospholipids (DPL)) and the structure (droplet size). RPOM-IFF showed a higher stability than POM-IFF. This effect can be attributed to its content of provitamin A compounds (in the form of carotenoids) which act in synergy with tocopherols and have beneficial effects for infant nutrition. The combined use of DPL and DFOM led to a better oxidative stability with a peroxide value twice lower than POM (stabilized with lecithin) after 20 days of storage at 40°C and less important tocopherols degradation. This favorable effect was even reinforced for smaller droplet sizes. Dairy lipids also provide a complex lipid profile and high content of short and medium saturated chain fatty acids which is beneficial for infant nutrition. The introduction of dairy lipids and carotenoids in DHA-enriched IFF composition are interesting levers of stabilization.