Maillard Reaction and Lactose Structural Changes during Milk Processing

Abstract

Heat treatments often generate chemicals which are not present in the raw materials. Such is the Maillard reaction which, while heating combinations of protein and reducing sugars, produces substances known as melanoidins (aldehydes and ketones) that improve health, help the body expel harmful material and act as anti-aging compounds. During heating of milk, lactose undergoes reactions that have important consequencesfor the milk: changes in flavor, colour, nutritive value, and pH may result. For more severetreatments, lactose isomerization or reaction withproteins is more suitable and specific indicators such aslactulose or furosine, and hydroxymethylfurfural, correlated witheach other, have been related to the intensity of milk heattreatment. Although Maillard reaction in milk usually manifests undesired side effects, at the same time some reactions serve as indicators of the extent of the heat treatments used during production, since their concentrations increase with the heat treatment.