Kinetic study on the Maillard reaction. Consideration of sugar reactivity

The aim of the present study was to compare five reducing sugars (ribose, xylose, arabinose, glucose and fructose) with respect to their relative reactivity in the Maillard reaction (MR) (55 °C, pH 6.5) with a shrimp hydrolysate. For each system, the extent of the MR was assessed for a 24-h period by monitoring browning intensity, free amino group disappearance and sugar consumption. Results revealed the prevailing propensity of pentoses over hexoses to react in the MR, with a distinguishable behaviour for the ribose-hydrolysate system. Interestingly, pentoses were shown to mainly differ in terms of reaction rate. Complementary data on the chemical composition of the MR products (MRPs) were provided by size-exclusion chromatography, thus demonstrating the occurrence of some molecular rearrangements detected at 294 nm. The modification of protein substrates through the MR could represent a key step in the formation of new molecules and constitute a promising means to produce high value-added ingredients with biological and techno-functional properties.