The Maillard Reaction in Powdered Infant Formula

Abstract

Powdered infant formulas are manufactured by dissolving dried ingredients in water or skimmed milk, which is then followed by pasteurization, homogenization, concentration in a vacuum evaporator and drying in spray dryer. Due to this large number of thermal processes, the formulas are subject to a series of reactions that can negatively impact their quality, among them the Maillard reaction. It is the result of chemical reactions between a carbonyl group of the reducing sugar and a free amino group of the protein or amino acid. During prolonged heating or storage of the powdered infant formula, a wide variety of reactive compounds are formed, which can then polymerize with protein residues and form dark pigments or melanoidins. The Maillard reaction is affected by several factors including pH, temperature, water activity, type of reducing sugar and presence of metals. It can result in numerous consequences, such as: an unavailability of amino acids, solubility loss, increase the allergenicity of certain proteins, and even impediment of mineral absorption. Much research is still needed to understand the consequences of the Maillard reaction in powdered infant formulas in order to find solutions that provide foods with high nutritional properties and are safe for the consumer.