Valorization of dairy by-products for milk-based infant formulas: A nutritional perspective review

The valorization of dairy by-products presents a sustainable approach to enhancing the nutritional quality of infant formulas while addressing environmental concerns. This review explores the potential of milk-derived components, including whey proteins, casein, lactose, galactooligosaccharides (GOS), and milk fat globule membrane (MFGM), in infant nutrition. These by-products, often sourced from dairy waste, exhibit functional and bioactive properties that mimic human breast milk, supporting infant growth, immune function, and gut health. MFGM, rich in phospholipids and bioactive peptides, promotes neurological development and reduces infection risks, while lactose and GOS foster beneficial gut microbiota. Besides, the review highlights biotechnological and physicochemical methods for valorizing dairy waste, such as enzymatic hydrolysis and membrane filtration, to recover high-value ingredients. Whey proteins, hydrolyzed for easier digestion, and casein derivatives, like A2 β-casein, offer hypoallergenic and growth-supporting benefits. GOS, synthesized from lactose, serves as a prebiotic, though its efficacy differs from human milk oligosaccharides (HMOs). Probiotics, derived from dairy or breast milk, further enhance gut microbiota and immune responses in formula-fed infants. Despite advancements, challenges remain in replicating breast milk's complexity, particularly in MFGM structure and HMO diversity. Regulatory standards and safety evaluations are critical for commercial application. Future research should focus on optimizing these components to bridge nutritional gaps and ensure safety, offering a promising pathway for sustainable and health-focused infant nutrition.