Chromatographic Determination of Bound Hydroxymethylfurfural as an Index of Milk Protein Glycosylation

Abstract

5-(Hydroxymethyl)-2-furfuraldehyde (HMF) is formed upon heat treatment of milk and milk-resembling systems by the Maillard reaction, via its Amadori product, and also by isomerization and subsequent degradation of sugars. Traditionally, the HMF content has been used as an indicator of both degradation routes. A new analytical approach has been developed for determining the HMF formed only by the acidic degradation of Amadori products, called bound HMF, and that could be related to the extent of the Maillard reaction due to heat treatment or long-term storage of foods. Optimal conditions for the acidic digestion procedure were determined. Reversed-phase HPLC is applied for accurate measurement of bound HMF. Keywords: Hydroxymethylfurfural; milk; Maillard reaction; HPLC analysis