The flavor quality differences of infant formula: The synergistic effects of nutritional components and chemical reactions

This study elucidates the interplay between nutritional composition and chemical reactions governing off-flavor formation in infant formula powder (IF). Sample Z, which is an IF of a raw bovine milk base with vegetable lipids (1,3-diolein-2-palmitin [OPO], sunflower, and flaxseed oils), showed accelerated oxidation (the oxidation products are twice those of sample J), generating propanal, pentanal, and hexanal, leading to metallic, fishy, and algae-like odors. Unsaturated lipids also promoted particle aggregation, vitamin degradation, and pungent aldehydes or ketones (2,4-octadienal, 1-octen-3-one). Sample J (IF of a raw caprine milk base with vegetable lipids [OPO, soybean, and corn oils]), containing γ-dodecalactone, exhibited floral or sweet notes but still retained fishy or metallic off-flavors. These findings underscore the crucial role of lipid composition in maintaining flavor stability, offering a practical approach for optimizing IF. By selectively incorporating oxidation-stable vegetable oils with balanced UFA profiles, off-flavor formation during storage can be minimized while ensuring adequate delivery of essential nutrients (e.g., docosahexaenoic acid, arachidonic acid, and eicosapentaenoic acid).