Changes in Furfural Compounds during Storage of Infant Milks

Abstract

The progress of the Maillard reaction in two infant milks (liquid and powdered forms of the same commercial brand) was monitored for 9 months of storage at 20, 30, and 37 °C. An increase in furfural compounds [hydroxymethylfurfural (HMF) and furfural (F)] was observed while no changes in available lysine occurred during storage at any temperature. In reconstituted powdered infant milk, at the three storage temperatures, the contents of free and total HMF ranged from 10.3 to 23.5 μmol/L and from 15.0 to 34.7 μmol/L, respectively. The content of free and total F ranged from 1.1 to 5.3 μmol/L and from 1.8 to 6.8 μmol/L, respectively. Free and total HMF content in liquid infant milk ranged from 0.6 to 1.6 μmol/L and from 9.0 to 12.2 μmol/L, respectively. The content of free and total F ranged from 0.3 to 0.6 μmol/L and from 1.4 to 2.3 μmol/L, respectively. Although free and total HMF and F were always higher in powdered milk than in liquid infant milk, in the latter the ratio total HMF/free HMF was more than 10 times that in powdered infant milk. On the basis of the increase in furfural compounds and by using the sum of free HMF and free F, an equation has been derived by which the shelf life of such products can be predicted. Keywords: HMF; F; furfural compounds; available lysine; infant milks